PPP1R13L

Gene Summary

Gene:PPP1R13L; protein phosphatase 1, regulatory subunit 13 like
Aliases: RAI, RAI4, IASPP, NKIP1
Location:19q13.32
Summary:IASPP is one of the most evolutionarily conserved inhibitors of p53 (TP53; MIM 191170), whereas ASPP1 (MIM 606455) and ASPP2 (MIM 602143) are activators of p53.[supplied by OMIM, Mar 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:relA-associated inhibitor
HPRD
Source:NCBIAccessed: 16 March, 2015

Ontology:

What does this gene/protein do?
Show (16)

Cancer Overview

Research Indicators

Publications Per Year (1990-2015)
Graph generated 16 March 2015 using data from PubMed using criteria.

Literature Analysis

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Tag cloud generated 16 March, 2015 using data from PubMed, MeSH and CancerIndex

Specific Cancers (4)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: PPP1R13L (cancer-related)

Rai TS, Cole JJ, Nelson DM, et al.
HIRA orchestrates a dynamic chromatin landscape in senescence and is required for suppression of neoplasia.
Genes Dev. 2014; 28(24):2712-25 [PubMed] Article available free on PMC after 15/06/2015 Related Publications
Cellular senescence is a stable proliferation arrest that suppresses tumorigenesis. Cellular senescence and associated tumor suppression depend on control of chromatin. Histone chaperone HIRA deposits variant histone H3.3 and histone H4 into chromatin in a DNA replication-independent manner. Appropriately for a DNA replication-independent chaperone, HIRA is involved in control of chromatin in nonproliferating senescent cells, although its role is poorly defined. Here, we show that nonproliferating senescent cells express and incorporate histone H3.3 and other canonical core histones into a dynamic chromatin landscape. Expression of canonical histones is linked to alternative mRNA splicing to eliminate signals that confer mRNA instability in nonproliferating cells. Deposition of newly synthesized histones H3.3 and H4 into chromatin of senescent cells depends on HIRA. HIRA and newly deposited H3.3 colocalize at promoters of expressed genes, partially redistributing between proliferating and senescent cells to parallel changes in expression. In senescent cells, but not proliferating cells, promoters of active genes are exceptionally enriched in H4K16ac, and HIRA is required for retention of H4K16ac. HIRA is also required for retention of H4K16ac in vivo and suppression of oncogene-induced neoplasia. These results show that HIRA controls a specialized, dynamic H4K16ac-decorated chromatin landscape in senescent cells and enforces tumor suppression.

Qiu S, Cai Y, Gao X, et al.
A small peptide derived from p53 linker region can resume the apoptotic activity of p53 by sequestering iASPP with p53.
Cancer Lett. 2015; 356(2 Pt B):910-7 [PubMed] Related Publications
One of the most important tumor suppression functions of p53 is its ability to induce apoptosis. iASPP is an inhibitory member of the ASPP protein family. It can specifically inhibit the normal function of p53 as a suppressor. The mechanism of iASPP suppressing the cell apoptotosis is through inhibiting the transactivation function of p53 on the promoters of proapoptotic genes by binding with p53. Therefore, relieving the combination of iASPP with p53 and leaving p53 free may be a useful strategy to activate p53 function. We therefore use A34, a small peptide derived from p53 linker region, to investigate the possibility of resuming the apoptosis activity of p53 by sequestering iASPP with p53 and derepressing p53. The results show that A34 can competitively combine with iASPP and therefore release p53 from iASPP; A34 can enhance the transcriptional activity of p53 on the promoters of Bax and PUMA; A34 can increase cell apoptosis and slow tumor growth in vitro and vivo. This study will open the way for using small molecule peptides that directly disturb the interaction of p53 with iASPP, thereby resume function of p53 as a suppressor.

Agarwal A, Cooke L, Riley C, et al.
Genetic and cytokine changes associated with symptomatic stages of CLL.
Leuk Res. 2014; 38(9):1097-101 [PubMed] Related Publications
The pathogenesis and drug resistance of symptomatic CLL patients involves genetic changes associated with the CLL clone as well as changes within the microenvironment. To further understand these processes, we compared early stage CLL to symptomatic late stage using gene expression and serum cytokine profiling to gain insight of the genetic and microenvironment changes associated with the most severe form of the disease. Patients were classified into low stage (Rai stage 0/I/II) and high stage (Rai stage III/IV). Gene expression profiles were obtained on pretreatment samples using the HG-U133A 2.0 Affymetrix platform. A comparison of low versus high stage CLL revealed a set of 21 genes differentially expressed genes. 15 genes were up regulated in the high stage compared to low stage while 6 genes were down regulated. Analysis of GO molecular function revealed 9 of 21 genes were involved in transcription factor activity. Serum cytokine profiles showed six cytokines to be significantly different in high stage patients. Two chemokines, SDF-1/CXCL12 and uPAR known to be involved in stem cell mobilization and homing were increased in serum of high stage patients. This study has identified therapeutic targets for symptomatic CLL patients.

Chen J, Xiao H, Huang Z, et al.
MicroRNA124 regulate cell growth of prostate cancer cells by targeting iASPP.
Int J Clin Exp Pathol. 2014; 7(5):2283-90 [PubMed] Article available free on PMC after 15/06/2015 Related Publications
Protein phosphatase 1, regulatory subunit 13 like PPP1R13L, also coined iASPP, was found high expression in prostate cancer tissues and cell lines. In previous research, in vitro and in vivo RNAi mediated by artificial lentiviral shRNAs which proved that suppression of iASPP decrease the proliferation of cancer cells. Endogenous interference RNAs, microRNAs play key roles in cell proliferation by post-transcriptional regulation of gene expression. Natural base pair matched microRNA for iASPP is mir124, which was found high expression in growth factorloss prostate cancer cell lines. In this study we examined effect of mir124 upon iASPP and proliferation of prostate cells in vitro with lentiviral infection and use artificial shRNA as control. In vitro reporter assay confirmed that mir124 binding the 3'UTR of iASPP and suppress mRNA expression. Lentivirus mediated mir124 expression decreased the proliferation and viability of PC3 while endogenous iASPP were knocked down.

Sharma KL, Rai R, Srivastava A, et al.
A multigenic approach to evaluate genetic variants of PLCE1, LXRs, MMPs, TIMP, and CYP genes in gallbladder cancer predisposition.
Tumour Biol. 2014; 35(9):8597-606 [PubMed] Related Publications
Gallbladder cancer (GBC) is a violent neoplasm associated with late diagnosis, unsatisfactory treatment, and poor prognosis. The disease shows complex interplay between multiple genetic variants. We analyzed 15 polymorphisms in nine genes involved in various pathways to find out combinations of genetic variants contributing to GBC risk. The genes included in the study were matrix metalloproteinases (MMP-2, MMP-7, and MMP-9), tissue inhibitor of metalloproteinases (TIMP-2), cytochrome P450 (CYP)1A1, CYP1B1, phospholipase C epsilon 1 (PLCE1), liver X receptor (LXR)-alpha, and LXR-beta. Genotypes were determined by PCR-RFLP and TaqMan probes. Statistical analysis was done by SPSS version 16. Multilocus analysis was performed by Classification and Regression Tree (CART) analysis and multifactor dimensionality reduction (MDR) to gene-gene interactions in modifying GBC risk. In silico analysis was done using various bioinformatics tools (F-SNP, FAST-SNP). Single locus analysis showed association of MMP-2 (-735 C > T, -1306 C > T), MMP-7 - 181 A > G, MMP-9 (P574R, R668Q), TIMP-2 - 418 G > C, CYP1A1-MspI, CYP1A1-Ile462Val, PLCE1 (rs2274223 A > G, rs7922612 T > C) and LXR-beta T > C (rs3546355 G > A, rs2695121 T > C) polymorphisms with GBC risk (p < 0.05) whereas CYP1B1 and LXR-α variants were not associated with GBC risk. Multidimensional reduction analysis revealed LXR-β (rs3546355 G > A, rs2695121 T > C), MMP-2 (-1306 C > T), MMP-9 (R668Q), and PLCE1 rs2274223 A > G to be key players in GBC causation (p < 0.001, CVC = 7/10). The results were further supported by independent CART analysis (p < 0.001). In silico analysis of associated variants suggested change in splicing or transcriptional regulation. Interactome and STRING analysis showed network of associated genes. The study found PLCE1 and LXR-β network interactions as important contributory factors for genetic predisposition in gallbladder cancer.

Lu M, Miller P, Lu X
Restoring the tumour suppressive function of p53 as a parallel strategy in melanoma therapy.
FEBS Lett. 2014; 588(16):2616-21 [PubMed] Related Publications
The tumour suppressor p53 is a master sensor of stress and it controls the expression of hundreds to thousands of genes with diverse biological functions including cell cycle arrest, apoptosis, and senescence. Consequently p53 is the most mutated gene found in human cancer and p53 mutation rate varies from 5% to 95%. Importantly p53 activity is often inactivated in tumours expressing structurally wild type p53. Thus one of the major challenges in cancer research is to restore the tumour suppressive function of p53. Intensive studies in the past decade have demonstrated that in addition to mutation, p53 activities are largely regulated by cellular factors that control the expression level and/or transcriptional activities of p53. MDM2, MDM4, p14(ARF) and the ASPP family of proteins are among the most studied regulators of p53. With increased understanding of the complexity of p53 regulation, various p53 reactivating approaches are being developed. This review will focus on the recent understanding of p53 inactivation in melanoma and the approaches to reactivate p53 in preclinical studies. Recent success in the therapeutic targeting of the BRAFV600E oncogenic protein was accompanied with subsequent relapse caused by acquired drug resistance. Restoration of the tumour suppressive function of p53 presents a parallel cancer therapeutic opportunity alongside BRAFV600E inhibition. Thus targeted therapy and concurrent reactivation of p53 may be a fertile ground to achieve synergistic killing of the 50% of cancer cells that express structurally wild type p53.

Gentile M, Cutrona G, Mosca L, et al.
Prospective validation of a risk score based on biological markers for predicting progression free survival in Binet stage A chronic lymphocytic leukemia patients: results of the multicenter O-CLL1-GISL study.
Am J Hematol. 2014; 89(7):743-50 [PubMed] Related Publications
A risk score based on three biological features (CD38, ZAP-70, and IGHV mutational status) was previously developed to predict progression-free survival (PFS) in untreated Binet A CLL patients. Here we perform a score validation analysis in a prospective and independent cohort of patients. Biological markers (CD38, ZAP-70, and IGHV mutational status) and gene expression profiles (GEP) of leukemic cells from CLL patients included in a prospective multicenter observational study (O-CLL1-GISL protocol, clinicaltrial.gov ID:NCT00917549) were used to assess the value and reproducibility of this score. To date, 468 Binet A patients were classified as low- (0 positive marker), intermediate- (1 positive marker), or high-risk (2 or 3 positive markers) using the progression risk score. The 3-year PFS probability was 91.7%, 82.9%, and 57.4% for low-, intermediate-, and high-risk (P < 0.0001) cases, respectively. These values were similar to those found in the original cohort. At Cox multivariate analysis, Rai stage, absolute lymphocyte count, progression risk score, and β-2 microglobulin maintained an independent prognostic impact on PFS. This score remained a predictor of progression when analysis was limited to 371 Rai 0 cases (P < 0.0001). Finally, the cells from the different CLL risk groups showed differences in their gene expression patterns. These results confirm the ability of this progression risk score to predict PFS among Binet A patients. The utility of the score was also extended by demonstrating that it retains prognostic value when applied exclusively to Rai 0 patients. Specific transcriptional patterns were significantly associated with risk groups.

Rai R, Sharma KL, Misra S, et al.
CYP17 polymorphism (rs743572) is associated with increased risk of gallbladder cancer in tobacco users.
Tumour Biol. 2014; 35(7):6531-7 [PubMed] Related Publications
Gallbladder cancer (GBC) involves interplay of sex steroids, including estrogen and progesterone. Since CYP17 is a key enzyme involved in estrogen and testosterone hormone biosynthesis as well as in xenobiotic metabolism, it may be a potential candidate gene in the carcinogenesis of the gallbladder. Hence, the present study aimed to investigate the association of CYP17 (rs2486758, and rs743572) polymorphisms with GBC susceptibility. The present study included a total of 414 histologically confirmed GBC and 230 healthy controls. The CYP17 (rs2486758 and rs743572) polymorphisms were genotyped by TaqMan-Allele discrimination assays. Statistical analysis was performed by using SPSS ver. 16. Overall, both the CYP17 SNPs did not indicate any association with GBC risk at genotype, haplotype, or at the genotypic interaction levels. However, in the case-only analysis, CYP rs743572 showed association with increased risk of GBC in tobacco users at hetero genotype and dominant models, as compared to non-user GBC patients. The TCrs2486758-AGrs743572 genotypic combination was also associated with increased GBC susceptibility in tobacco users. CYP17 rs743572 is associated with increased risk of GBC in tobacco users in the North Indian population. However, the study requires confirmation in other populations.

Jia Y, Peng L, Rao Q, et al.
Oncogene iASPP enhances self-renewal of hematopoietic stem cells and facilitates their resistance to chemotherapy and irradiation.
FASEB J. 2014; 28(7):2816-27 [PubMed] Related Publications
iASPP is a member of the apoptosis-stimulating proteins of p53 (ASPP) family and negatively regulates the apoptotic function of p53. In a hematopoietic system, overexpression of iASPP results in blockage of apoptosis, which may play a role in regulating hematopoietic stem cell (HSC) numbers. To address this, we first analyzed the expression of iASPP in patients with acute leukemia (AL) and found it was highly expressed in patients with AL. We further established a transgenic mouse model in which human iASPP was specifically expressed in hematopoietic cells. Overexpression of iASPP led to an increase in the proportion of long-term HSCs, short-term HSCs, multipotent progenitors, and common myeloid progenitor. HSCs from iASPP transgenic mice had an advantage in long-term reconstitution potential. In addition, the hematopoietic cells from iASPP transgenic mice exhibited a significantly lower level of p53 dependent apoptosis. After irradiation damage, hematopoietic cells of iASPP transgenic mice had a higher level of γ-H2AX expression, which lasted for a longer time. These results provide the first evidence that the iASPP can increase HSC populations and reconstitution capacity. Interestingly, in response to cell damage stimuli, hematopoietic cells can be protected against apoptosis by iASPP; meanwhile these apoptosis-resistant cells would have more mutation accumulation, which might be the potential risk for malignant transformation.-Jia, Y., Peng, L., Rao, Q., Xing, H., Huai, L., Yu, P., Chen, Y., Wang, C., Wang, M., Mi, Y., Wang, J. Oncogene iASPP enhances self-renewal of hematopoietic stem cells and facilitates their resistance to chemotherapy and irradiation.

Offenmüller S, Ravindranath Y, Goyette G, et al.
Focused screening of a panel of cancer-related genetic polymorphisms reveals new susceptibility loci for pediatric acute lymphoblastic leukemia.
Pediatr Blood Cancer. 2014; 61(8):1411-5 [PubMed] Related Publications
BACKGROUND: A genetic predisposition to acute lymphoblastic leukemia (ALL) in childhood is well established. Currently known risk loci, however, explain only one third of the estimated total risk related to common genetic variations.
PROCEDURE: We genotyped 1,421 polymorphisms in 407 candidate genes from the SNP500Cancer database (National Cancer Institute) using the Illumina Cancer SNP Panel. We investigated 78 cases (aged 0-19 years at diagnosis, and mixed ethnic background) of childhood B-precursor ALL and compared genotype data with those of 1,417 HapMap controls. To account for the ethnic diversity of the study population, structured association by genetically matching cases and controls using identity-by-state similarity was used. Case-control association analyses were performed using Cochran-Mantel-Haenszel tests, adjusted for the population substructure.
RESULTS: Common variations rs6966 (3' UTR of PPP1R13L, chr 19q13.32, P = 4.55 × 10(-9)) and rs414580 (intron 2 of MSR1, chr 8p22, P = 6.09 × 10(-8)) were significantly associated with ALL. These SNPs remained significant after adjustment for multiple testing. The SNP rs6966 tags a haplotype block which includes SNPs in PPP1R13L and ERCC2 genes, which are related to DNA repair and cell survival. rs6966 and rs414580 conferred allelic odds ratios of 3.74 (95% confidence interval [CI] 2.31-6.04) and 3.93 (95% CI 2.31-6.69), respectively.
CONCLUSIONS: These findings reveal two independent novel susceptibility loci for childhood ALL.

Rai R, Sharma KL, Sharma S, et al.
Death receptor (DR4) haplotypes are associated with increased susceptibility of gallbladder carcinoma in north Indian population.
PLoS One. 2014; 9(2):e90264 [PubMed] Article available free on PMC after 15/06/2015 Related Publications
BACKGROUND AND AIM: Defective apoptosis is a hallmark of cancer development and progression. Death receptors (DR4, FAS) and their ligands (TRAIL, FASL) are thought to mediate the major extrinsic apoptotic pathway in the cell. SNPs in these genes may lead to defective apoptosis. Hence, the present study aimed to investigate the association of functional SNPs of DR4 (rs20575, rs20576 and rs6557634), FAS (rs2234767) and FASL (rs763110) with gallbladder cancer (GBC) risk.
METHODS: This case-control study included 400 GBC and 246 healthy controls (HC). Genotyping was carried out by Taqman genotyping assays. Statistical analysis was performed by using SPSS ver16. Meta-analysis was performed using Comprehensive Meta-analysis software (Version 2.0, BIOSTAT, Englewood, NJ) to systematically summarize the possible association of SNP with cancer risk. Functional prediction of these variants was carried out using Bioinformatics tools (FAST-SNP, F-SNP). False discovery rate (FDR test) was used in multiple comparisons.
RESULTS: The DR4 C rs20575 A rs20576 A rs6557634, G rs20575 A rs20576 G rs6557634 and G rs20575 C rs20576 G rs6557634 haplotypes conferred two-fold increased risk for GBC. Among these, the DR4 C rs20575 A rs20576 A rs6557634 haplotype emerged as main factor influencing GBC susceptibility as the risk was not modulated by gender or gallstone stratification. Our meta-analysis results showed significant association of DR4 rs6557634 with overall cancer risk, GI cancers as well as in Caucasians. We didn't find any association of FAS and FASL SNPs with GBC susceptibility.
CONCLUSIONS: The DR4 haplotype C rs20575 A rs20576 A rs6557634 represents an important factor accounting the patients susceptibility to GBC probably due to decreased apoptosis. However, additional well-designed studies with larger sample size focusing on different ethnicities are required to further validate the results.

Kabekkodu SP, Bhat S, Radhakrishnan R, et al.
DNA promoter methylation-dependent transcription of the double C2-like domain β (DOC2B) gene regulates tumor growth in human cervical cancer.
J Biol Chem. 2014; 289(15):10637-49 [PubMed] Article available free on PMC after 11/04/2015 Related Publications
Double C2-like domain β (DOC2B) gene encodes for a calcium-binding protein, which is involved in neurotransmitter release, sorting, and exocytosis. We have identified the promoter region of the DOC2B gene as hypermethylated in pre-malignant, malignant cervical tissues, and cervical cancer cell lines by methylation-sensitive dimethyl sulfoxide-polymerase chain reaction and bisulfite genome sequencing; whereas, it was unmethylated in normal cervical tissues (p < 0.05). The promoter hypermethylation was inversely associated with mRNA expression in SiHa, CaSki, and HeLa cells and treatment with demethylating agent 5-aza-2-deoxycytidine restored DOC2B expression. The region -630 to +25 bp of the DOC2B gene showed robust promoter activity by a luciferase reporter assay and was inhibited by in vitro artificial methylation with Sss1 methylase prior to transient transfections. Overexpression of the DOC2B gene in SiHa cells when compared with controls showed significantly reduced colony formation, cell proliferation, induced cell cycle arrest, and repressed cell migration and invasion (p < 0.05). Ectopic expression of DOC2B resulted in anoikis-mediated cell death and repressed tumor growth in a nude mice xenograft model (p < 0.05). DOC2B expressing cells showed a significant increase in intracellular calcium level (p < 0.05), impaired AKT1 and ERK1/2 signaling, and induced actin cytoskeleton remodeling. Our results show that promoter hypermethylation and silencing of the DOC2B gene is an early and frequent event during cervical carcinogenesis and whose reduced expression due to DNA promoter methylation may lead to selective cervical tumor growth.

Rai R, Sharma KL, Misra S, et al.
Association of adrenergic receptor gene polymorphisms in gallbladder cancer susceptibility in a North Indian population.
J Cancer Res Clin Oncol. 2014; 140(5):725-35 [PubMed] Related Publications
PURPOSE: Gallbladder cancer (GBC), the most common gastrointestinal and biliary tract malignancy, often coincides with gallstone disease (GSD). The genetic variants of adrenergic receptor (ADR) have been previously reported to be associated with hypomotility disorder of cardiovascular system and GSD. Since GSD may function as GBC precursor, the present study aimed to investigate the association of common functional genetic variants of ADRA2A C-1291G, ADRβ3 T190C or Trp64Arg, and ADRβ1 C1165G or Arg389Gly with GBC and GSD susceptibility.
METHODS: The present study included a total of 400 histologically confirmed GBC, 230 GSD, and 268 healthy controls. The ADRA2A C-1291G, ADRβ3 T190C, and ADRβ1 C1165G polymorphisms were determined by PCR-RFLP. Statistical analysis was performed by using SPSS version 16.
RESULTS: ADRβ3 T190C polymorphism was significantly associated with increased risk of GBC (CT: Pcorr = 0.015, OR 2.87; CC: Pcorr = 0.038, OR 10.33; C allele: Pcorr = 0.014, OR 2.7; CT + CC: Pcorr = 0.017, OR 3.05). These associations existed even after gallstone and gender stratification. Similarly, ADRβ3 T190C polymorphism was also associated with GSD risk, though limited only to female GSD patients. In contrary, ADRA2A C-1291G conferred a marginally increased risk only in GSD patients. ADRβ1 C1165G polymorphism was not associated with GBC and GSD susceptibility when compared to controls.
CONCLUSION: ADRβ3 T190C polymorphism is significantly associated with GBC and GSD susceptibility. The ADRβ3 T190C may be involved in the pathophysiology of GBC by both gallstone-dependent pathway and by some other independent mechanisms.

Rai PS, Pai GC, Alvares JF, et al.
Intraindividual somatic variations in MTHFR gene polymorphisms in relation to colon cancer.
Pharmacogenomics. 2014; 15(3):349-59 [PubMed] Related Publications
AIM: MTHFR mediates the one carbon metabolism pathway. Two common genetic variants, C677T and A1298C, of MTHFR are associated with number of human diseases, including cancer, as well as being involved in the modulation of therapy outcome to antifolate drugs. To understand the distribution pattern of SNPs among different tissues of an individual, we examined MTHFR polymorphisms in normal and colon cancer tissues and compared the genotype frequencies in peripheral blood samples.
MATERIALS & METHODS: DNA was isolated from tumor tissue and matched normal tissues from 155 colon cancer patients. These samples as well as DNA from blood samples of the control group (n = 294) were analyzed for MTHFR polymorphisms by PCR-RFLP and confirmed by a direct DNA sequencing method.
RESULTS: Our data suggest that the allele and genotype frequencies of C677T and A1298C were significantly different between tumor tissues and both types of normal tissues. We have established that MTHFR variants that exist in tumor and matched normal tissues of colon cancer patients differ suggesting somatic variation in MTHFR polymorphisms among different tissues of an individual. The MTHFR A1298C polymorphism was associated with risk of colon cancer.
CONCLUSION: Different MTHFR variants may exist in different tissues to maintain physiological functions and may have implications for disease susceptibility and pharmacogenomics based therapies. Original submitted 21 January 2013; Revision submitted 3 January 2014.

Fröhlich E, Wahl R
The current role of targeted therapies to induce radioiodine uptake in thyroid cancer.
Cancer Treat Rev. 2014; 40(5):665-74 [PubMed] Related Publications
Targeted therapy pinpointing specific alteration in cancer cells has gained an important role in the treatment of cancer. Compounds that re-induce thyroid-specific functions could be particularly useful in differentiated thyroid cancers by rendering them susceptible to radioiodine treatment, which is relatively specific and has few adverse effects. This review describes the rationale for radioiodine treatment, considering the targets of compounds with differentiation-inducing effects, and the impact of these drugs on the expression of thyroid-specific proteins and on iodine-uptake. We survey the results from the clinical trials thus far performed. We conclude that although retinoids, thiazolidinediones, histone deacetylase inhibitors and DNA methyltransferase inhibitors do increase the expression of thyroid-specific proteins, their clinical efficacy is limited. The relatively low rate of remissions in clinical trials with re-differentiating compounds could be due to low levels of the target, heterogeneity of iodine uptake into the tumor, poor correlation of radioiodine uptake and clinical remission, and/or the slow onset of the therapeutic effect. Although the mode of action is not clear, the combination of tyrosine kinase inhibitors and RAI treatment could improve clinical responses in non-radioiodine avid metastatic thyroid carcinoma.

Wang LQ, Kwong YL, Kho CS, et al.
Epigenetic inactivation of miR-9 family microRNAs in chronic lymphocytic leukemia--implications on constitutive activation of NFκB pathway.
Mol Cancer. 2013; 12:173 [PubMed] Article available free on PMC after 11/04/2015 Related Publications
BACKGROUND: The miR-9 family microRNAs have been identified as a tumor suppressor miRNA in cancers. We postulated that miR-9-1, miR-9-2 and miR-9-3 might be inactivated by DNA hypermethylation in chronic lymphocytic leukemia (CLL).
METHODS: Methylation of miR-9-1, miR-9-2 and miR-9-3 was studied in eight normal controls including normal bone marrow, buffy coat, and CD19-sorted peripheral blood B-cells from healthy individuals, seven CLL cell lines, and seventy-eight diagnostic CLL samples by methylation-specific polymerase chain reaction.
RESULTS: The promoters of miR-9-3 and miR-9-1 were both unmethylated in normal controls, but methylated in five (71.4%) and one of seven CLL cell lines respectively. However, miR-9-2 promoter was methylated in normal controls including CD19 + ve B-cells, hence suggestive of a tissue-specific but not tumor-specific methylation, and thus not further studied. Different MSP statuses of miR-9-3, including complete methylation, partial methylation, and complete unmethylation, were verified by quantitative bisulfite methylation analysis. 5-Aza-2'-deoxycytidine treatment resulted in miR-9-3 promoter demethylation and re-expression of pri-miR-9-3 in I83-E95 and WAC3CD5+ cells, which were homozygously methylated for miR-9-3. Moreover, overexpression of miR-9 led to suppressed cell proliferation and enhanced apoptosis together with downregulation of NFκB1 in I83-E95 cells, supporting a tumor suppressor role of miR-9-3 in CLL. In primary CLL samples, miR-9-3 was detected in 17% and miR-9-1 methylation in none of the patients at diagnosis. Moreover, miR-9-3 methylation was associated with advanced Rai stage (≥ stage 2) (P = 0.04).
CONCLUSIONS: Of the miR-9 family, miR-9-3 is a tumor suppressor miRNA relatively frequently methylated, and hence silenced in CLL; whereas miR-9-1 methylation is rare in CLL. The role of miR-9-3 methylation in the constitutive activation of NFκB signaling pathway in CLL warrants further study.

Rosenfeldt MT, O'Prey J, Morton JP, et al.
p53 status determines the role of autophagy in pancreatic tumour development.
Nature. 2013; 504(7479):296-300 [PubMed] Related Publications
Macroautophagy (hereafter referred to as autophagy) is a process in which organelles termed autophagosomes deliver cytoplasmic constituents to lysosomes for degradation. Autophagy has a major role in cellular homeostasis and has been implicated in various forms of human disease. The role of autophagy in cancer seems to be complex, with reports indicating both pro-tumorigenic and tumour-suppressive roles. Here we show, in a humanized genetically-modified mouse model of pancreatic ductal adenocarcinoma (PDAC), that autophagy's role in tumour development is intrinsically connected to the status of the tumour suppressor p53. Mice with pancreases containing an activated oncogenic allele of Kras (also called Ki-Ras)--the most common mutational event in PDAC--develop a small number of pre-cancerous lesions that stochastically develop into PDAC over time. However, mice also lacking the essential autophagy genes Atg5 or Atg7 accumulate low-grade, pre-malignant pancreatic intraepithelial neoplasia lesions, but progression to high-grade pancreatic intraepithelial neoplasias and PDAC is blocked. In marked contrast, in mice containing oncogenic Kras and lacking p53, loss of autophagy no longer blocks tumour progression, but actually accelerates tumour onset, with metabolic analysis revealing enhanced glucose uptake and enrichment of anabolic pathways, which can fuel tumour growth. These findings provide considerable insight into the role of autophagy in cancer and have important implications for autophagy inhibition in cancer therapy. In this regard, we also show that treatment of mice with the autophagy inhibitor hydroxychloroquine, which is currently being used in several clinical trials, significantly accelerates tumour formation in mice containing oncogenic Kras but lacking p53.

Jochemsen AG
Reactivation of p53 as therapeutic intervention for malignant melanoma.
Curr Opin Oncol. 2014; 26(1):114-9 [PubMed] Related Publications
PURPOSE OF REVIEW: Targeted therapy of malignant melanoma recently experienced remarkable advances with gene mutation-based therapies with signaling pathway inhibitors (kinase inhibitors). The treatments prolong patients' survival, but in general resistance is acquired and progression of disease occurs. Therefore, additional therapeutic targets are desperately needed.
RECENT FINDINGS: The p53 tumor suppressor gene is rarely mutated in melanoma, but its functional attenuation is needed for tumor development. Recently, it was found that the essential p53 inhibitor Mdmx is very frequently overexpressed in melanoma. Mdmx displays both p53-dependent and p53-independent oncogenic effects needed for melanoma growth
SUMMARY: Current melanoma therapy based upon kinase inhibitors shows robust initial clinical effect, but the duration of effect is limited. Inactivation of Mdmx in melanoma inhibits tumor growth also of kinase-inhibitor-resistant tumors. An observed synergistic effect of kinase-inhibition and Mdmx targeting can lead to better and more durable treatment of melanoma patients.

Pilarski R, Cebulla CM, Massengill JB, et al.
Expanding the clinical phenotype of hereditary BAP1 cancer predisposition syndrome, reporting three new cases.
Genes Chromosomes Cancer. 2014; 53(2):177-82 [PubMed] Article available free on PMC after 11/04/2015 Related Publications
The clinical phenotype of BAP1 hereditary cancer predisposition syndrome (MIM 614327) includes uveal melanoma (UM), cutaneous melanoma (CM), renal cell carcinoma (RCC), and mesothelioma. However, the frequency of the syndrome in patients with UM and the association with other cancers are still not clear. In this study, we screened 46 previously untested, unrelated UM patients with high risk for hereditary cancer for germline mutation in BAP1. We also studied four additional patients with a personal or family history suggestive of BAP1 hereditary cancer syndrome. We identified three patients with germline pathogenic mutations (c.2050 C>T, pGln684*; c.1182C>G, p.Tyr394*, and c.1882_1885delTCAC, p. Ser628Profs*8) in BAP1. Two of these three patients presented with UM and the third with a metastatic adenocarcinoma likely from a hepatic cholangiocarcinoma. Reported family histories included UM, mesothelioma, RCC, CM, and several other internal malignancies. The results of this study confirm the association between germline BAP1 mutation and predisposition to UM, mesothelioma, CM and RCC. However, other cancers, such as cholangiocarcinoma and breast carcinoma may be part of the phenotype of this hereditary cancer predisposition syndrome. In addition, the results support the existence of other candidate genes in addition to BAP1 contributing to hereditary predisposition to UM.

Hus I, Bojarska-Junak A, Chocholska S, et al.
Th17/IL-17A might play a protective role in chronic lymphocytic leukemia immunity.
PLoS One. 2013; 8(11):e78091 [PubMed] Article available free on PMC after 11/04/2015 Related Publications
Th17 cells, a recently discovered subset of T helper cells that secrete IL-17A, can affect the inflammation process autoimmune and cancer diseases development. The purpose of this study was to evaluate the role of Th17 cells and IL17A in biology of CLL. The study group included 294 untreated CLL patients in different clinical stages. Here, we show that higher Th17 and IL-17A values were associated with less advanced clinical stage of CLL. Th17 cells' percentages in PB were lower in patients who died due to CLL during follow-up due to CLL (as compared to surviving patients) and in patients responding to first-line therapy with fludarabine-based regimens (as compared to non-responders). IL-17A inversely correlated with the time from CLL diagnosis to the start of therapy and was lower in patients who required treatment during follow-up. Th-17 and IL-17A values were lower in patients with adverse prognostic factors (17p and 11q deletion, CD38 and ZAP-70 expression). CLL patients with detectable IL-17A mRNA in T cells were in Rai Stage 0 and negative for both ZAP-70 and CD38 expression. Th17 percentages positively correlated with iNKT and adversely with Treg cells. The results of this study suggest that Th17 may play a beneficial role in CLL immunity.

Yin J, Vogel U, Wang H, et al.
HapMap-based study identifies risk sub-region on chromosome 19q13.3 in relation to lung cancer among Chinese.
Cancer Epidemiol. 2013; 37(6):923-9 [PubMed] Related Publications
BACKGROUND: Chromosome 19q13.3 has been identified as one of the regions that associate with cancer risk in previous studies.
METHODS: We systematically examined the 70.772kb region comprising four genes on chromosome 19q13.3 among Chinese using the haplotype-tagging SNP (htSNP) approach and the HapMap platform. The study involved 339 lung cancer cases and 358 non-cancer controls. Two htSNPs (rs1046282 and rs735482) captured most of the common haplotypes of CD3EA and the combined effects of sixteen htSNPs provided high coverage of common haplotypes of ERCC2, PPP1R13L, CD3EAP and ERCC1.
RESULTS: Both carriers of variant CC genotype [adjusted OR (95% CI)=1.28 (1.02-1.60), P=0.04] and variant C-allele among >20 years' smokers [OR (95% CI)=2.13 (1.24-3.67), P=0.006] for CD3EAP rs735482 were at increased risk of lung cancer. Four haplotype blocks of strong linkage disequilibrium were identified. The haplotype ERCC2 rs3916874(G) and rs238415(C) [OR (95% CI)=1.26 (1.02-1.57), P=0.03] in block 1 and the haplotype PPP1R13L rs4803817(A), CD3EAP rs1046282(T), rs735482(C), ERCC1 rs3212980(A), rs3212964(G) [OR (95% CI)=3.56 (1.55-8.18), P=0.005] in block 3 were associated with lung cancer risk. MDR (multifactor dimensionality reduction) analysis demonstrated the best significant model of two-attributes containing smoking duration and rs2298881 in ERCC1 (P=0.004-0.005) and suggested that the effects of high-order interactions among smoking duration and ERCC2, PPP1R13, ERCC1 htSNPs could modulate lung cancer risk.
CONCLUSIONS: HapMap-based study of 19q13.3 identified that genetic variation of CD3EAP and two loci were associated with lung cancer risk and interaction of smoking duration and genetic variants was the strongest predictor of lung cancer risk in a Chinese population.

Yoon JH, Kim Y, Yahng SA, et al.
Validation of Western common recurrent chromosomal aberrations in Korean chronic lymphocytic leukaemia patients with very low incidence.
Hematol Oncol. 2014; 32(4):169-77 [PubMed] Related Publications
In Asia, the incidence of chronic lymphocytic leukaemia (CLL) is lower than in Western countries. Only a few studies of CLL have been conducted in Korea, and no long-term clinical outcome data are available. We assessed the frequency of common chromosomal aberrations in Korean CLL patients using interphase fluorescence in situ hybridization (FISH) and investigated their relationship to clinical outcomes. Between 2000 and 2011, conventional cytogenetic studies were performed in 58 patients, and FISH results were available in 48 patients. We used six DNA probes for the detection of del(13q14), trisomy 12, del(11q22), del(17p13), IGH rearrangement and del(6q23). Chromosomal aberrations were identified in 15 of 58 patients (26%) with conventional cytogenetic studies and in 25 of 48 patients (52%) with interphase FISH, including six patients with complex karyotypes. In contrast with the results of Western studies, trisomy 12 was the most common aberration, followed by IGH rearrangement, del(13q14), del(11q22) and del(17p13). Deletion of 6q23 was not observed, and isolated del(13q14) was less frequent than in Western studies. Compared with the other types of chromosomal aberrations, patients with del(11q22) and del(17p13) were more likely to be Rai stage 3-4 and Binet stage C, resulting in poor responses to chemotherapy and worse outcomes. In contrast, patient with trisomy 12 and isolated del(13q14) showed better responses and superior survival outcomes. The incidence of CLL is lower in Korea than in Western countries, and the frequency of chromosomal aberrations differs, perhaps reflecting differences in the pathogenic mechanism between ethnicities. Large prospective studies are needed to further assess the prognostic value of these results in Korean CLL patients.

Morabito F, Mosca L, Cutrona G, et al.
Clinical monoclonal B lymphocytosis versus Rai 0 chronic lymphocytic leukemia: A comparison of cellular, cytogenetic, molecular, and clinical features.
Clin Cancer Res. 2013; 19(21):5890-900 [PubMed] Related Publications
PURPOSE: To investigate the incidence and clinical relevance of classic and new prognostic markers, IGHV gene mutational status, and chromosomal abnormalities in clinical monoclonal B lymphocytosis (cMBL) compared with Rai stage 0 chronic lymphocytic leukemia (Rai0-CLL).
EXPERIMENTAL DESIGN: A group of 136 patients with cMBL and a group of 216 Rai0-CLL cases were investigated prospectively.
RESULTS: IGHV-mutated cases were significantly more frequent among cMBLs (P = 0.005), whereas the distribution of CD38 and ZAP-70 positive cases, of patients with NOTCH1 and SF3B1 mutations or exhibiting the major CLL cytogenetic abnormalities, was similar in the two groups. Moreover, no significant differences were found either in IGHV/IGHD/IGHJ gene usage or in the overall prevalence of stereotyped IGHV gene sequences. Cells from cMBL and Rai0-CLL exhibited similar gene and microRNA (miRNA) signatures; in addition, when grouped according to the IGHV mutational status, IGHV-unmutated cases showed different transcriptional signatures compared with IGHV-mutated patients, irrespective of the cMBL or Rai0-CLL classification. cMBL diagnosis per se was predictive of longer progression-free survival.
CONCLUSIONS: Our study based on a prospective series of patients indicates that no major differences exist between the circulating cells from cMBL and Rai0-CLL, at least based on a comparison of the markers used in the study. This possibly suggests that the two conditions mainly differ in the initial size of the monoclonal cell population, which may influence the subsequent timing of clonal expansion and clinical manifestations.

Kanaan Z, Roberts H, Eichenberger MR, et al.
A plasma microRNA panel for detection of colorectal adenomas: a step toward more precise screening for colorectal cancer.
Ann Surg. 2013; 258(3):400-8 [PubMed] Related Publications
OBJECTIVE: The main objective of this study was to investigate the potential use of circulating microRNAs (miRNAs) as biomarkers of colorectal (CR) adenomas.
BACKGROUND: Detection of precancerous lesions such as CR adenoma is a key to reduce CR cancer (CRC) mortality. There is a great need for accurate, noninvasive biomarkers for detection of CR adenoma and CRC. MiRNAs are non-protein-coding RNAs that regulate gene expression. Our prior work investigated the dysregulation of 5 plasma miRNAs in CRC patients. As intended, we undertook a more comprehensive plasma-miRNA screening study in patients with CR adenoma and CRC.
METHODS: We screened for 380 plasma-miRNAs using microfluidic array technology (Applied BioSystems) in a screening cohort of 12 healthy controls, 9 patients with CR adenomas, and 20 patients with CRC. A panel of the most dysregulated miRNAs (P < 0.05, False Discovery Rate: 5%) was then validated in a blinded cohort of 26 healthy controls, 16 patients with large adenomas, and 45 patients with CRC.
RESULTS: A panel of 8 plasma miRNAs (miR-532-3p, miR-331, miR-195, miR-17, miR-142-3p, miR-15b, miR-532, and miR-652) distinguished polyps from controls with high accuracy [area under curve (AUC) = 0.868 (95% confidence interval [CI]: 0.76-0.98)]. In addition, a panel of 3 plasma miRNAs (miR-431, miR-15b, and miR-139-3p) distinguished Stage IV CRC from controls with an [AUC = 0.896 (95% CI: 0.78-1.0)]. Receiver-operating-characteristic curves of miRNA panels for all CRC versus controls and polyps versus all CRC showed AUC values of 0.829 (95% CI: 0.73-0.93) and 0.856 (95% CI: 0.75-0.97), respectively.
CONCLUSIONS: Plasma miRNAs are reliable, noninvasive, and inexpensive markers for CR adenomas. This miRNA panel warrants study in larger cohorts. Plasma-based assays could provide better screening compliance compared to fecal occult blood or endoscopic screening.

Rai R, Sharma KL, Misra S, et al.
PSCA gene variants (rs2294008 and rs2978974) confer increased susceptibility of gallbladder carcinoma in females.
Gene. 2013; 530(2):172-7 [PubMed] Related Publications
BACKGROUND AND AIM: PSCA is a tissue specific tumor suppressor or oncogene which has been found to be associated with several human tumors including gallbladder cancer. It is considered to be involved in the cell-proliferation inhibition and/or cell-death induction activity. Therefore, we aimed to investigate the role of PSCA gene polymorphisms in gallbladder cancer risk in North Indian population.
METHODOLOGY: A total of 405 gallbladder cancer patients and 247 healthy controls were included in the case-control study for risk prediction. We examined the association of two functional SNPs, rs2294008 and rs2978974 in PSCA gene by genotyping using Taqman allelic discrimination assays. Statistical analysis was done using SPSS software, version 17. Linkage disequilibrium and haplotype analysis was done with the help of SNPstats software. FDR test was used to correct for multiple comparisons.
RESULTS: No significant associations of rs2294008 and rs2978974 genetic variants of the PSCA gene were found with GBC risk at allele, genotype or haplotype levels. Stratifying the subjects on the basis of gallstone also did not show any significant result. However, on gender stratification, we found a significant association of Trs2294008-Grs2978974 haplotype with higher risk of GBC in females (FDR Pcorr=0.021, OR=1.6). In contrary, Trs2294008-A rs2978974 haplotype conferred significant lower risk in males (FDR Pcorr=0.013; OR=0.25).
CONCLUSIONS: These findings suggest that PSCA genetic variants may have a significant effect on GBC susceptibility in a gender specific manner.

Liu Y, Higgins CD, Overstreet CM, et al.
Peptides that bind specifically to an antibody from a chronic lymphocytic leukemia clone expressing unmutated immunoglobulin variable region genes.
Mol Med. 2013; 19:245-52 [PubMed] Article available free on PMC after 11/04/2015 Related Publications
Chronic lymphocytic leukemia (CLL) is a clonal disease of a subset of human B lymphocytes. Although the cause of the disease is unknown, its development and evolution appear to be promoted by signals delivered when B-cell receptors (BCRs) engage (auto)antigens. Here, using a peptide phage display library of enhanced size and diverse composition, we examined the binding specificity of a recombinant monoclonal antibody (mAb) constructed with the heavy chain and light chain variable domains of a CLL BCR that does not exhibit somatic mutations. As determined by testing the peptides identified in the selected peptide phage pool, this CLL-associated unmutated mAb bound a diverse set of sequences, some of which clustered in families based on amino acid sequence. Synthesis of these peptides and characterization of binding with the CLL-associated mAb revealed that mAb-peptide interactions were generally specific. Moreover, the mAb-peptide interactions were of lower affinities (micromolar KD), as measured by surface plasmon resonance, than those observed with a CLL mAb containing somatic mutations (nanomolar KD) and with immunoglobulin heavy chain variable (IGHV)-mutated antibodies selected by environmental antigens. This information may be of value in identifying and targeting B lymphocytes expressing specific BCRs in CLL patients and healthy subjects with monoclonal B lymphocytosis.

Burton DG, Giribaldi MG, Munoz A, et al.
Androgen deprivation-induced senescence promotes outgrowth of androgen-refractory prostate cancer cells.
PLoS One. 2013; 8(6):e68003 [PubMed] Article available free on PMC after 11/04/2015 Related Publications
Androgen deprivation (AD) is an effective method for initially suppressing prostate cancer (PC) progression. However, androgen-refractory PC cells inevitably emerge from the androgen-responsive tumor, leading to incurable disease. Recent studies have shown AD induces cellular senescence, a phenomenon that is cell-autonomously tumor-suppressive but which confers tumor-promoting adaptations that can facilitate the advent of senescence-resistant malignant cell populations. Because androgen-refractory PC cells emerge clonally from the originally androgen-responsive tumor, we sought to investigate whether AD-induced senescence (ADIS) affects acquisition of androgen-refractory behavior in androgen-responsive LNCaP and LAPC4 prostate cancer cells. We find that repeated exposure of these androgen-responsive cells to senescence-inducing stimuli via cyclic AD leads to the rapid emergence of ADIS-resistant, androgen-refractory cells from the bulk senescent cell population. Our results show that the ADIS phenotype is associated with tumor-promoting traits, notably chemoresistance and enhanced pro-survival mechanisms such as inhibition of p53-mediated cell death, which encourage persistence of the senescent cells. We further find that pharmacologic enforcement of p53/Bax activation via Nutlin-3 prior to establishment of ADIS is required to overcome the associated pro-survival response and preferentially trigger pervasive cell death instead of senescence during AD. Thus our study demonstrates that ADIS promotes outgrowth of androgen-refractory PC cells and is consequently a suboptimal tumor-suppressor response to AD.

Jeon HS, Jin G, Kang HG, et al.
A functional variant at 19q13.3, rs967591G>A, is associated with shorter survival of early-stage lung cancer.
Clin Cancer Res. 2013; 19(15):4185-95 [PubMed] Related Publications
PURPOSE: This study was conducted to investigate the associations between single-nucleotide polymorphisms (SNP) in 19q13.3 and survival of patients with early-stage non-small cell lung cancer (NSCLC), and to define the causative functional SNP of the association.
EXPERIMENTAL DESIGN: A two-stage study design was used to evaluate five SNPs in relation to survival outcomes in 328 patients and then to validate the results in an independent patient population (n = 483). Luciferase assay and real-time PCR were conducted to examine functional relevance of a potentially functional SNP.
RESULTS: Of the five SNPs, three SNPs (rs105165C>T, rs967591G>A, and rs735482A>C) were significantly associated with survival outcomes in a stage I study. The rs967591A allele had significantly higher activity of the CD3EAP promoter compared with the rs967591G allele (P = 0.002), but the SNP did not have an effect on the activity of PPP1R13L promoter. The rs967591G>A was associated with the level of CD3EAP mRNA expression in lung tissues (P = 0.01). The rs967591G>A exhibited consistent associations in a stage II study. In combined analysis, the rs967591 AA genotype exhibited a worse overall survival (adjusted HR = 1.69; 95% confidence interval = 1.29-2.20; P = 0.0001).
CONCLUSION: The rs967591G>A affects CD3EAP expression and thus influences survival in early-stage NSCLC. The analysis of the rs967591G>A polymorphism can help identify patients at high risk of a poor disease outcome.

Amiri-Kordestani L, Luchenko V, Peer CJ, et al.
Phase I trial of a new schedule of romidepsin in patients with advanced cancers.
Clin Cancer Res. 2013; 19(16):4499-507 [PubMed] Article available free on PMC after 11/04/2015 Related Publications
PURPOSE: Romidepsin is a potent histone deacetylase inhibitor (HDI) with activity in T-cell lymphoma. Given preclinical data showing greater induction of gene expression with longer exposures to HDIs, a phase I study of a day 1, 3, and 5 romidepsin schedule was evaluated. A secondary objective was to assess the effect of romidepsin on radioactive iodine (RAI) uptake in thyroid cancers.
EXPERIMENTAL DESIGN: Open-label, single-arm, phase I, 3 + 3 dose escalation study. Romidepsin was administered as a 4-hour infusion on days 1, 3, and 5 of a 21-day cycle. Pharmacokinetics (PK) and pharmacodynamics (PD) were assessed, including histone acetylation in peripheral blood mononuclear cells (PBMC), RAI uptake in refractory thyroid cancer, and HDI-related ECG changes.
RESULTS: Twenty-eight patients with solid tumors, including 11 patients with thyroid cancer were enrolled. Six dose levels were explored, and 7 mg/m(2) on days 1, 3, and 5 was identified as tolerable. No Response Evaluation Criteria In Solid Tumors-defined objective responses were recorded although 9 patients had stable disease a median 30 weeks (range, 21-112) including 6 with thyroid cancer a median of 33 weeks. PD studies detected acetylated histones in PBMCs and ECG changes beginning at low dose levels. Follow-up RAI scans in patients with RAI refractory thyroid cancer did not detect meaningful increases.
CONCLUSIONS: A romidepsin dose of 7 mg/m(2) administered on days 1, 3, and 5 was found tolerable and resulted in histone acetylation in PBMCs. Although there were no objective responses with romidepsin alone, this schedule may be useful for developing combination studies in solid tumors.

Hallek M
Chronic lymphocytic leukemia: 2013 update on diagnosis, risk stratification and treatment.
Am J Hematol. 2013; 88(9):803-16 [PubMed] Related Publications
DISEASE OVERVIEW: Chronic lymphocytic leukemia (CLL) is the commonest leukemia in western countries. The disease typically occurs in elderly patients and has a highly variable clinical course. Leukemic transformation is initiated by specific genomic alterations that impair apoptosis of clonal B-cells.
DIAGNOSIS: The diagnosis is established by blood counts, blood smears, and immunophenotyping of circulating B-lymphocytes, which identify a clonal B-cell population carrying the CD5 antigen as well as B-cell markers.
PROGNOSIS: Two prognostic staging systems exist, the Rai and Binet staging systems, which are established by physical examination and blood counts. Various biological and genetic markers also have prognostic value. Deletions of the short arm of chromosome 17 (del(17p)) predict resistance to most available therapies.
THERAPY: Patients with active or symptomatic disease or with advanced Binet or Rai stages require therapy. For physical fit patients, chemoimmunotherapy with fludarabine, cyclophosphamide and rituximab represents the current standard therapy. For unfit patients, treatment with an anti-CD20 antibody plus a milder chemotherapy (chlorambucil) is currently established as standard treatment. At relapse, the initial treatment may be repeated, if the treatment-free interval exceeds two years. If the disease relapses earlier, alternative therapies such as bendamustine alone or with rituximab, alemtuzumab, lenalidomide, or ofatumumab should be used. Patients with a del(17p) or TP53 should be considered for an allogeneic SCT.
FUTURE CHALLENGES: Several new agents (e.g., ibrutinib, obinutuzumab) hold the potential to change standard of CLL treatment in the next 6-12 months. Therefore, CLL patients should be included into current clinical trials whenever possible.

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