Transposable elements (TEs) are an abundant and rich genetic resource of regulatory sequences

OBJECTIVE: The aim of this study was to analyze the expression, biological role and clinical relevance of cancer stem cell markers in high-grade serous carcinoma (HGSC).
METHODS: mRNA expression by qRT-PCR of NANOG, OCT4, SOX2, SOX4, SOX9, LIN28A and LIN28B was analyzed in 134 HGSC specimens (84 effusions, 50 surgical specimens). Nanog, OCT3/4, SOX2 and SOX9 protein expression by immunohistochemistry was analyzed in 52 HGSC effusions. Nanog protein expression in exosomes from 80 HGSC effusions was studied by Western Blotting. OVCAR3 cells underwent CRISPR/Cas9 Nanog knockout (KO), and the effect of Nanog KO on migration, invasion, proliferation and proteolytic activity was analyzed in OVCAR3 and OVCAR8 cells.
RESULTS: OCT4 mRNA was overexpressed in effusions compared to solid specimens (p = 0.046), whereas SOX9 was overexpressed in the ovarian tumors compared to effusions and solid metastases (p = 0.003). Higher SOX2 and SOX9 expression was associated with primary (intrinsic) chemoresistance (p = 0.009 and p = 0.02, respectively). Higher SOX9 levels were associated with shorter overall survival in univariate (p = 0.04) and multivariate (p = 0.049) analysis. OCT3/4, SOX2 and SOX9 proteins were found in HGSC cells, whereas Nanog was detected only in exosomes. Higher SOX2 protein expression was associated with shorter overall survival in univariate analysis (p = 0.049). OVCAR cells exposed to OVCAR3 NANOG KO exosomes had reduced migration, invasion and MMP9 activity.
CONCLUSIONS: SOX2 and SOX9 mRNA levels in HGSC effusions may be markers of clinically aggressive disease. Nanog is secreted in HGSC exosomes in effusions and modulates tumor-promoting cellular processes in vitro.

BACKGROUND: The lethal-7 (
AIM: To investigate the role of
METHODS: A total of 898 gastric cancer patients and 992 tumor-free controls were recruited into this study from 2008 to 2013. Gastric cancer patients were followed periodically. Ten single nucleotide polymorphisms (SNPs) in the
RESULTS: All the ten SNPs were in Hardy-Weinberg equilibrium. The C allele of the rs3811463 polymorphism in the 3'-untranslated region (UTR) of
CONCLUSION: The

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer. Previous studies have found that many microRNAs (miRNAs), including miRNA‑126‑3p, may play a critical role in the development of LUAD. However, no study of LUAD has researched the synergistic effects and co‑targets of both miRNA‑126‑3p and miRNA‑126‑5p. The present study used real‑time quantitative polymerase chain reaction (RT‑qPCR) to explore the expression values of miRNA‑126‑3p and miRNA‑126‑5p in 101 LUAD and 101 normal lung tissues. Ten relevant microarray datasets were screened to further validate the expression levels of miRNA‑126‑3p and ‑5p in LUAD. Twelve prediction tools were employed to obtain potential targets of miRNA‑126‑3p and miRNA‑126‑5p. The results showed that both miRNA‑126‑3p and ‑5p were expressed significantly lower in LUAD. A significant positive correlation was also present between miRNA‑126‑3p and ‑5p expression in LUAD. In addition, lower expression of miRNA‑126‑3p and ‑5p was indicative of vascular invasion, lymph node metastasis (LNM), and a later tumor/node/metastasis (TNM) stage of LUAD. The authors obtained 167 targets of miRNA‑126‑3p and 212 targets of miRNA‑126‑5p; 44 targets were co‑targets of both. Eight co‑target genes (IGF2BP1, TRPM8, DUSP4, SOX11, PLOD2, LIN28A, LIN28B and SLC7A11) were initially identified as key genes in LUAD. The results of the present study indicated that the co‑regulation of miRNA‑126‑3p and miRNA‑126‑5p plays a key role in the development of LUAD, which also suggests a fail‑proof mode between miRNA‑3p and miRNA‑126‑5p.

BACKGROUND Lin28 is a gene involved in many biological processes, including development, glucose metabolism, and tumorigenesis. Let-7 miRNA is a tumor-suppressor gene that is frequently inactivated in cancer cells. The role of c-Myc (a target gene of let-7) and the Lin28-let-7-c-Myc pathway in the growth and malignancy of thyroid cancer is unclear. The purpose of the present study was to evaluate the expression of Lin28A, let-7a, and c-Myc in human papillary thyroid carcinoma (PTC) and to investigate their potential mechanisms in the progression of PTC. MATERIAL AND METHODS Lin28A and c-Myc expression were assessed in PTC tissues and PTC cell lines using immunohistochemistry, Western blotting, and real-time PCR. CCK-8 and Transwell assays were performed to evaluate PTC cell proliferation, migration, and invasion in cells in which the expression of Lin28A was downregulated by RNA interference or in which let-7a was overexpressed after transfection with let-7a mimics. RESULTS The expression of Lin28A and c-Myc was upregulated in PTC tissues and cell lines, whereas the expression of let-7a was downregulated in PTC cell lines. Clinically, Lin28A was linked to a higher tumor/node/metastasis stage and the presence of lymph node metastases. Moreover, knockdown of Lin28A activated let-7a processing and inhibited the expression of the downstream gene c-Myc, suppressing cell proliferation, migration, and invasion. Similar results were obtained after let-7a overexpression. CONCLUSIONS The Lin28A/let-7a/c-Myc pathway is involved in cancer growth and malignant behavior in PTC and is a potential target for therapeutic intervention in this disease.

OBJECTIVES: Cancer-testis antigens (CTAs) are defined as proteins that are specifically expressed in testis or placenta and their expression is frequently activated in cancer. Due to their ability to induce an immune response, CTAs may serve as suitable targets for immunotherapy. The aim of this study was to evaluate if there is reactivity against CTAs in the plasma of non-small cell lung cancer (NSCLC) patients through the detection of circulating antibodies.
MATERIALS AND METHODS: To comprehensively analyze autoantibodies against CTAs the multiplexing capacities of suspension bead array technology was used. Bead arrays were created with 120 protein fragments, representing 112 CTAs. Reactivity profiles were measured in plasma samples from 133 NSCLC patients and 57 cases with benign lung diseases.
RESULTS: Altogether reactivity against 69 antigens, representing 81 CTAs, was demonstrated in at least one of the analyzed samples. Twenty-nine of the antigens (45 CTAs) demonstrated exclusive reactivity in NSCLC samples. Reactivity against cancer-testis antigen family 47; member A (CT47A) genes, P antigen family member 3 (PAGE3), variable charge X-linked (VCX), melanoma antigen family B1 (MAGEB1), lin-28 homolog B (LIN28B) and chromosome 12 open reading frame 54 (C12orf54) were only found in NSCLC patients at a frequency of 1%-4%. The presence of autoantibodies towards these six antigens was confirmed in an independent group of 34 NSCLC patients.
CONCLUSION: We identified autoantibodies against CTAs in the plasma of lung cancer patients. The reactivity pattern of autoantibodies was higher in cancer patients compared to the benign group, stable over time, but low in frequency of occurrence. The findings suggest that some CTAs are immunogenic and that these properties can be utilized as immune targets.

Neuroblastoma, a pediatric tumor of the sympathetic nervous system, is predominantly driven by copy number aberrations, which predict survival outcome in global neuroblastoma cohorts and in low-risk cases. For high-risk patients there is still a need for better prognostic biomarkers. Via an international collaboration, we collected copy number profiles of 556 high-risk neuroblastomas generated on different array platforms. This manuscript describes the composition of the dataset, the methods used to process the data, including segmentation and aberration calling, and data validation. t-SNE analysis shows that samples cluster according to MYCN status, and shows a difference between array platforms. 97.3% of samples are characterized by the presence of segmental aberrations, in regions frequently affected in neuroblastoma. Focal aberrations affect genes known to be involved in neuroblastoma, such as ALK and LIN28B. To conclude, we compiled a unique large copy number dataset of high-risk neuroblastoma tumors, available via R2 and a Shiny web application. The availability of patient survival data allows to further investigate the prognostic value of copy number aberrations.

Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy. LIN28 homolog A (LIN28A) is a RNA‑binding protein, which serves a fundamental role in cell development and pluripotency. Polo‑like kinase 4 (PLK4) is a member of the polo‑like kinase family, which primarily takes part in the mitotic regulation. Overexpression of LIN28A has been demonstrated in ovarian cancer; however, the expression of PLK4 and the correlation between the expression of LIN28A and PLK4 in EOC has not been discussed. In the present study, the mRNA and protein levels of LIN28A and PLK4 were evaluated by reverse transcription‑quantitative polymerase chain reaction and immunohistochemistry in ovarian tissues of patients. Results demonstrated significantly increased expression in EOC compared with benign epithelial ovarian tumors. High expression of LIN28A and PLK4 was detected at the advanced pathological stage. Furthermore, PLK4 expression was positively correlated with LIN28A (r=0.555; P=0.039). The median survival analysis of patients with EOC with LIN28A and PLK4 double positive expression was 14 months, compared with 30 months in single positive and 60 months in double negative patients by Kaplan‑Meier analysis (P<0.05). The expressions of LIN28A and PLK4 was elevated in different EOC cell lines compared to with a normal ovarian cell line. The 293T cells transfected with LIN28A plus a PLK4 plasmid were the fastest‑growing group. These results suggest that co‑expression of LIN28A and PLK4 may be associated with poor prognosis of EOC and could serve as promising prognostic biomarkers and therapeutic targets in EOC. LIN28A and PLK4 may be used along with traditional morphological and clinical characteristics for predicting prognosis.

Our previous work found cancer-testis (CT) genes as a new source of epi-driver candidates of cancer. LIN28B was a CT gene, but the "driver" ability and the activation mechanism in lung adenocarcinoma (LUAD) remain unclear. We observed that LIN28B expression was restricted in testis. It was re-activated in LUAD patients without known genomic alterations in oncogenes and was related to poorer survival. In vitro and In vivo experiments confirmed that the activation of LIN28B could promote the proliferation and metastasis of LUAD cells and can influence cell cycle, DNA damage repair, and genome instability. In addition to the known let-7-LIN28B regulation loop, our results further revealed a let-7-independent Cis-regulator of LIN28B: LIN28B-AS1. LIN28B-AS1 is a CT long non-coding RNA (CT-lncRNA). It altered the messenger RNA stability of LIN28B by directly interacting with another CT protein IGF2BP1 but not with LIN28B and constituted a novel regulation network. In sum, we identify that LIN28B is an "epi-driver" of LUAD and clarify a new lncRNA-activated mechanism of LIN28B, which provide new candidate targets for precise anticancer therapy in the future.

Ovarian cancer (OC) is the leading cause of death among women with gynecologic malignant diseases, however, the molecular mechanism of ovarian cancer is not well defined. Previous studies have found that RNA binding protein Lin28A is a key factor of maintain the pluripotency of stem cells, and it is positively correlated with the degree of several cancers (breast, prostate, liver cancer, etc). Our previous study shows that Lin28A is highly expressed in OC tissues and is involved in the regulation of OC cell biological behavior. In this study, we confirmed that high expression of Lin28A promoted the survival, invasion, metastasis, and inhibited the apoptosis of OC cells. Lin28A interacts with Rho associated coiled-coil containing protein kinase2 (ROCK2) but not ROCK1 and upregulates the expression of ROCK2 in OC cells. The binding sites of each other were identified by truncated mutations and Immuno-precipitaion (IP) assay. After knock down of ROCK2 in cells with high expression of Lin28A, the survival, invasion, metastasis was significantly inhibited and early apoptosis was increased in OC cells and OC xenograft in nude mice. Our experimental data also showed that knock down of ROCK2 but not ROCK1 inhibited the invasion by decreasing the expression of N-cadherin, Slug, β-catenin and increasing ZO-1 expression. Simultaneously, knock down of ROCK2 induced cell apoptosis by increasing cleaved Caspase-9,cleaved Caspase-7, and cleaved Caspase-3. Taken together, Lin28A regulated the biological behaviors in OC cells through ROCK2 and the interaction of Lin28A/ROCK2 may be a new target for diagnosis and gene therapy of OC.

RNA-binding proteins (RBPs) are expressed broadly during both development and malignant transformation, yet their mechanistic roles in epithelial homeostasis or as drivers of tumor initiation and progression are incompletely understood. Here we describe a novel interplay between RBPs LIN28B and IMP1 in intestinal epithelial cells. Ribosome profiling and RNA sequencing identified

BACKGROUND: Long non-coding RNAs (lncRNAs) have emerged as important regulators of human cancers. However, the functional roles of lncRNAs and the mechanisms responsible for their aberrant expression in gastric cancer (GC) have not been well characterized.
METHODS: In this study, we examined the expression of lncRNA UFC1 in GC by qRT-PCR and explored its correlation with clinicopathological parameters. In vitro cell functional assays and in vivo animal studies were performed to determine the roles of UFC1 in GC progression.
RESULTS: UFC1 was elevated and predicted poorer prognosis in GC. UFC1 knockdown inhibited while UFC1 overexpression promoted GC cell proliferation, migration, and invasion. UFC1 bound to miR-498 to antagonize its tumor suppressive effect on Lin28b. Suppression of Lin28b by miR-498 could be rescued by UFC1 overexpression, whereas Lin28b overexpression partially rescued UFC1 knockdown-mediated inhibition of GC cell function. Lin28b expression was increased in GC and suggested a co-expression pattern with UFC1.
CONCLUSIONS: UFC1 has a promoting role in GC progression, at least in part, by acting as a miR-498 sponge and derepressing Lin28b expression, which would provide a novel biomarker for GC diagnosis and prognosis and offer a potential target for GC therapy.

This work aims to explore the roles and related mechanisms of RNA binding protein Lin28B in gastric cancer cells stemness. We found that Lin28B expression was negatively correlated with the overall survival (OS) of gastric cancer patients, and significantly increased in gastric cancer cells compared with that in gastric epithelial cells. Lin28B overexpression increased spheroid formation, expression of gastric cancer stemness-related markers, and decreased cisplatin sensitivity in gastric cancer cells. Mechanistically, Lin28B could directly bind to NRP-1 3'UTR, thus increasing NRP-1 mRNA stability and expression, and activate the downstream Wnt/β-catenin signaling. Knockdown of NRP-1 or treatment with Wnt/β-catenin antagonist could rescue the promotive effects of Lin28B on gastric cancer stemness. Thus, thes results indicate that Lin28B could facilitate gastric cancer stemness via directly binding to NRP-1 3'UTR and activating the downstream Wnt/β-catenin signaling.

TGF-β/Activin induces epithelial-to-mesenchymal transition and stemness in pancreatic ductal adenocarcinoma (PDAC). However, the microRNAs (miRNAs) regulated during this response have remained yet undetermined. Here, we show that TGF-β transcriptionally induces MIR100HG lncRNA, containing miR-100, miR-125b and let-7a in its intron, via SMAD2/3. Interestingly, we find that although the pro-tumourigenic miR-100 and miR-125b accordingly increase, the amount of anti-tumourigenic let-7a is unchanged, as TGF-β also induces LIN28B inhibiting its maturation. Notably, we demonstrate that inactivation of miR-125b or miR-100 affects the TGF-β-mediated response indicating that these miRNAs are important TGF-β effectors. We integrate AGO2-RIP-seq with RNA-seq to identify the global regulation exerted by these miRNAs in PDAC cells. Transcripts targeted by miR-125b and miR-100 significantly overlap and mainly inhibit p53 and cell-cell junctions' pathways. Together, we uncover that TGF-β induces an lncRNA, whose encoded miRNAs, miR-100, let-7a and miR-125b play opposing roles in controlling PDAC tumourigenesis.

An abnormality in the Lin28/let-7a axis is relevant to the progression of hepatitis B virus (HBV)-positive hepatocellular carcinoma (HCC), which could be a novel therapeutic target for this malignant tumor. The present study aimed to investigate the antiproliferative and anti-invasive effects of urolithin A in a stable full-length HBV gene integrated cell line HepG2.2.15 using CCK-8 and transwell assays. The RNA and protein expressions of targets were assessed by quantitative PCR and western blot, respectively. Results revealed that urolithin A induced cytotoxicity in HepG2.2.15 cells, which was accompanied by the cleavage of caspase-3 protein and down-regulation of Bcl-2/Bax ratio. Moreover, urolithin A suppressed the protein expressions of Sp-1, Lin28a, and Zcchc11, and elevated the expression of microRNA let-7a. Importantly, urolithin A also regulated the Lin28a/let-7a axis in transient HBx-transfected HCC HepG2 cells. Furthermore, urolithin A decelerated the HepG2.2.15 cell invasion, which was involved in suppressing the let-7a downstream factors HMGA2 and K-ras. These findings indicated that urolithin A exerted the antiproliferative effect by regulating the Lin28a/let-7a axis and may be a potential supplement for HBV-infected HCC therapy.

OBJECTIVE: Infantile hemangiomas (IHs) are the most common benign vascular neoplasms of infancy, characterized by a rapid growth phase followed by a spontaneous involution, or triggered by propranolol treatment by poorly understood mechanisms. LIN28/let-7 axis plays a central role in the regulation of stem cell self-renewal and tumorigenesis. However, the role of LIN28B/let-7 signaling in IH pathogenesis has not yet been elucidated.
APPROACH AND RESULTS: LIN28B is highly expressed in proliferative IH and is less expressed in involuted and in propranolol-treated IH samples as measured by immunofluorescence staining and quantitative RT-PCR. Small RNA sequencing analysis of IH samples revealed a decrease in microRNAs that target LIN28B, including let-7, and an increase in microRNAs in the mir-498(46) cistron. Overexpression of LIN28B in HEK293 cells induced the expression of miR-516b in the mir-498(46) cistron. Propranolol treatment of induced pluripotent stem cells, which express mir-498(46) endogenously, reduced the expression of both LIN28B and mir-498(46) and increased the expression of let-7. Furthermore, propranolol treatment reduced the proliferation of induced pluripotent stem cells and induced epithelial-mesenchymal transition.
CONCLUSIONS: This work uncovers the role of the LIN28B/let-7 switch in IH pathogenesis and provides a novel mechanism by which propranolol induces IH involution. Furthermore, it provides therapeutic implications for cancers in which the LIN28/let-7 pathway is imbalanced.

MicroRNA-125a exhibits an antiproliferative activity and is downregulated in several types of tumors, including hepatocellular carcinoma where it targets sirtuin-7, matrix metalloproteinase-11, and c-Raf. Another target of miR-125a is Lin28, a pluripotency factor that is generally undetectable in differentiated cells but is often upregulated/reactivated in tumors where it acts as an oncogenic factor promoting cell proliferation and tumor progression. In this study we show that downregulation of Lin28b by miR-125a partially accounts for its antiproliferative activity toward hepatocellular carcinoma cells. We also found that Lin28b is able to bind a conserved GGAG motif of pre-miR-125a and to inhibit its maturation in hepatocellular carcinoma cells. Reciprocal inhibition between miR-125a and Lin28b reasonably generates a positive feedback loop where reactivation of Lin-28b inhibits the expression of both miR-125a and let-7, reinforcing its own expression and leading to a marked overexpression of the mitogenic targets of the two miRNAs. On the other hand, perturbation of these circuits by overexpression of miR-125a suppresses Lin28b leading to a decreased cell proliferation. Overall, these data support a tumor suppressive role for miR-125a and contribute to the elucidation of its molecular targets.

RNA-binding protein LIN28B is frequently overexpressed in human colon cancer and is associated with the tumor progression and poor prognosis. The potential molecular mechanisms underlying the role of LIN28B in colon cancer remain unclear. The present study aimed to explore the role of B-cell lymphoma 2 (BCL-2) in promoting colon cancer development associated with LIN28B. The expression pattern of LIN28B in colon cancer tissues and cell lines was detected by RT-PCR, Western blotting analysis, and immunohistochemical staining. A log rank test was carried out to compare the survival times of patients with high/low levels of LIN28B. The effects of LIN28B on cell clonal formation, growth, and apoptosis were detected by clone formation, MTT and flow cytometry assays, respectively. BCL-2 expression and protein stability after LIN28B up-regulation were assessed by Western blotting. The effects of LIN28B and BCL-2 on tumorigenesis were evaluated by an in vivo xenograft assay. The results showed that LIN28B was highly expressed in colon cancer tissues and cell lines, which could promote cell clonal formation and growth and inhibit cell apoptosis. Up-regulation of LIN28B increased BCL-2 expression, enhanced its stability, and reduced its ubiquitination. Overexpression of LIN28B promoted cell tumorigenesis, whereas this effect was repressed by knockdown of BCL-2. This study suggests that overexpression of LIN28B promotes colon cancer development by increasing BCL-2 expression, potentially opening up new avenues for therapeutic approaches to colon cancer treatment.

HOXB7 is a homeodomain (HOX) transcription factor involved in regional body patterning of invertebrates and vertebrates. We previously identified HOXB7 within a ten-gene prognostic signature for lung adenocarcinoma, where increased expression of HOXB7 was associated with poor prognosis. This raises the question of how HOXB7 overexpression can influence the metastatic behavior of lung adenocarcinoma. Here, we analyzed publicly available microarray and RNA-seq lung cancer expression datasets and found that HOXB7-overexpressing tumors are enriched in gene signatures characterizing adult and embryonic stem cells (SC), and induced pluripotent stem cells (iPSC). Experimentally, we found that HOXB7 upregulates several canonical SC/iPSC markers and sustains the expansion of a subpopulation of cells with SC characteristics, through modulation of LIN28B, an emerging cancer gene and pluripotency factor, which we discovered to be a direct target of HOXB7. We validated this new circuit by showing that HOXB7 enhances reprogramming to iPSC with comparable efficiency to LIN28B or its target c-MYC, which is a canonical reprogramming factor.

Background: Hepatoblastoma (HB) is the most common liver tumor of childhood and occurs predominantly within the first 3 years of life. In accordance to its early manifestation, HB has been described to display an extremely low mutation rate. As substitute, epigenetic modifiers seem to play an exceptional role in its tumorigenesis, which holds promise to develop targeted therapies and establish biomarkers for patient risk stratification.
Results: We examined the role of a newly described protein complex consisting of three epigenetic regulators, namely E3 ubiquitin-like containing PHD and RING finger domain 1 (UHRF1), ubiquitin-specific-processing protease 7 (USP7), and DNA methyltransferase 1 (DNMT1), in HB. We found the complex to be located on the promoter regions of the pivotal HB-associated tumor suppressor genes (TSGs)
Conclusion: These findings suggest that UHRF1 is critical for aberrant TSG silencing and sustained growth signaling in HB and that

LIN28B is a RNA-binding protein regulating predominantly let-7 microRNAs with essential functions in inflammation, wound healing, embryonic stem cells, and cancer. LIN28B expression is associated with tumor initiation, progression, resistance, and poor outcome in several solid cancers, including lung cancer. However, the functional role of LIN28B, especially in non-small cell lung adenocarcinomas, remains elusive. Here, we investigated the effects of LIN28B expression on lung tumorigenesis using LIN28B transgenic overexpression in an autochthonous KRAS

The diversity and complexity of the cancer transcriptome may contain transcripts unique to the tumor environment. Here, we report a LIN28B variant, LIN28B-TST, which is specifically expressed in hepatocellular carcinoma (HCC) and many other cancer types. Expression of LIN28B-TST is associated with significantly poor prognosis in HCC patients. LIN28B-TST initiates from a de novo alternative transcription initiation site that harbors a strong promoter regulated by NFYA but not c-Myc. Demethylation of the LIN28B-TST promoter might be a prerequisite for its transcription and transcriptional regulation. LIN28B-TST encodes a protein isoform with additional N-terminal amino acids and is critical for cancer cell proliferation and tumorigenesis. Our findings reveal a mechanism of LIN28B activation in cancer and the potential utility of LIN28B-TST for clinical purposes.

Juvenile myelomonocytic leukemia (JMML), a rare and aggressive myelodysplastic/myeloproliferative neoplasm that occurs in infants and during early childhood, is characterized by excessive myelomonocytic cell proliferation. More than 80% of patients harbor germ line and somatic mutations in RAS pathway genes (eg,

BACKGROUND: The let-7 microRNAs (miRNAs) are frequently dysregulated in carcinogenic processes, including cervical cancer. LIN28 proteins regulate let-7 biogenesis by binding to conserved sequences within the pre-miRNA structure. Nevertheless, recent research has shown that some let-7 miRNAs may escape LIN28 regulation.
OBJECTIVE: Correlate pre-let-7 miRNAs and LIN28B levels in cervical cell lines with different malignancy and HPV content.
METHODS: Pre-let-7 levels were determined by RTqPCR. LIN28B and other let-7 targets were analyzed by immunoblot. In silico tools were used to correlate let-7 and LIN28B expression and to analyze prelet- 7 sequences and structures.
RESULTS: Lin28B protein was detected in all tested cell lines although it was more expressed in tumor cell lines. High levels of pre-let-7c/f-1 and pre-miR-98 were present in almost all cell lines regardless malignancy and LIN28B expression. Pre-let-7g/i were mainly expressed in tumor cell lines, pre-let-7e and pre-let-7-a3 were absent in all cell lines and pre-let-7a-2 showed indistinct expression. LIN28B showed positive correlation with pre-let-7i/g/f-1 and pre-miR-98 in tumor cell lines, suggesting escape from regulation. Sequence alignment and analysis of pre-let-7 miRNAs showed distinctive structural features within the preE region that may influence the ideal pre-let-7 structuring for LIN28B interaction. Short preE-stems were present in pre-let-7 that may escape LIN28B regulation, but long preEstems were mostly associated with high-level pre-let-7 miRNAs.
CONCLUSION: The observed differences of pre-let-7 levels in cervical cell lines may be the result of alternative preE structuring affecting interaction with LIN28B thus resulting in differential let-7 regulation.

The RNA-binding protein LIN28B plays an important role in development, stem cell biology, and tumorigenesis. LIN28B has two isoforms: the LIN28B-long and -short isoforms. Although studies have revealed the functions of the LIN28B-long isoform in tumorigenesis, the role of the LIN28B-short isoform remains unclear and represents a major gap in the field. The LIN28B-long and -short isoforms are expressed in a subset of human colorectal cancers and adjacent normal colonic mucosa, respectively. To elucidate the functional and mechanistic aspects of these isoforms, colorectal cancer cells (Caco-2 and LoVo) were generated to either express no LIN28B or the -short or -long isoform. Interestingly, the long isoform suppressed

BACKGROUND: Lin28B and its paralog Lin28A are small RNA binding proteins that have similar inhibitory effects, although they target separate steps in the maturation of let-7 miRNAs in mammalian cells. Because Lin28B participates in the promotion and development of tumors mostly by blocking the let-7 tumor suppressor family members, we sought to explore the associated mechanisms to gain insights into how Lin28B might be decreased in human cancer cells to increase let-7 levels and reverse malignancy.
RESULTS: We demonstrated that the histone acetyltransferase PCAF, via its cold shock domain, directly interacts with and subsequently acetylates Lin28B in lung adenocarcinoma-derived H1299 cells. RT-qPCR assays showed that both let-7a-1 and let-7g were increased in PCAF-transfected H1299 cells. Lin28B is acetylated by ectopic PCAF and translocates from the nucleus to the cytoplasm in H1299 cells.
CONCLUSIONS: The effects of acetylated Lin28B on let-7a-1 and let-7g are similar to that of stable knockdown of Lin28B in H1299 cells. The new role of PCAF in mediating Lin28B acetylation and the specific release of its target microRNAs in H1299 cells may shed light on the potential application of let-7 in the clinical treatment of lung cancer patients.

Ornithine Decarboxylase (ODC) is a key enzyme involved in polyamine synthesis and is reported to be up regulated in several cancers. However, the effect of ODC gene silencing in retinoblastoma is to be understood for utilization in therapeutic applications. Hence, in this study, a novel siRNA (small interference RNA) targeting ODC was designed and validated in Human Y79 retinoblastoma cells for its effects on intracellular polyamine levels, Matrix Metalloproteinase 2 & 9 activity and Cell cycle. The designed siRNA showed efficient silencing of ODC mRNA expression and protein levels in Y79 cells. It also showed significant reduction of intracellular polyamine levels and altered levels of oncogenic LIN28b expression. By this study, a regulatory loop is proposed, wherein, ODC silencing in Y79 cells to result in decreased polyamine levels, thereby, leading to altered protein levels of Lin28b, MMP-2 and MMP-9, which falls in line with earlier studies in neuroblastoma. Thus, by this study, we propose ODC silencing as a prospective strategy for targeting retinoblastoma.

Exposure to ambient particulate matter (PM) has been linked to the increasing incidence and mortality of lung cancer, but the principal toxic components and molecular mechanism remain to be further elucidated. In this study, human lung adenocarcinoma A549 cells were treated with serial concentrations of water-extracted PM

OBJECTIVES: To explore the effects of Lin28A on progression of osteocarcinoma (OS) cells.
RESULTS: Lin28A mRNA and protein expressions were significantly increased in OS tissues compared with that in normal adjacent tissues. Expressions of Lin28A and long noncoding RNA MALAT1 were positively correlated. Patients with higher Lin28A expression had shorter overall survival. Moreover, Lin28A knockdown inhibited OS cells proliferation, migration, invasion and promoted cell apoptosis; Lin28A was found to harbor binding sites on MALAT1 sequences and associated with MALAT1, and increased MALAT1 stability and expression. Notably, the inhibition of Lin28A knockdown was attenuated or even reversed by MALAT1 overexpression.
CONCLUSIONS: RNA binding protein Lin28A could facilitate OS cells progression by associating with the long noncoding RNA MALAT1.

Lung carcinoma tops the categories of cancer related motility, and has been treated as the main threat to human health. The functions and related mechanism of FBXW7 controlled lung cancer stem cells' signatures is barely unknown, and the miR-367 regulations of FBXW7 via Wnt signaling have not been explored. Cancer stem cells of either ALDH1+ or CD133+ phenotype were found to be referred to advanced stages in patients with NSCLC (non-small cell lung carcinoma). To study the roles of miR-367, we found greater miR-367 level or FBXW7 level was reserved in NSCLC than that of paired adjacent normal tissues, and their upregulations were positively correlated with Wnt signaling activation. On the contrary, increased miR-367 was correlated with Let-7 repression. MiR-367 was related to stronger sphere forming ability in stem cells of NSCLC. We then explored the functions of the endogenous miR-367 in stem-like cells isolated from NSCLC cell lines. In HEK-293 cells, we identified FBXW7 as the direct downstream gene of miR-367, which consequently released the LIN-28 dependent inhibition of suppressive Let-7. Through informatics analysis, miR-367 was predicated to function through Wnt signaling, and decreased Let-7 played the pivotal role to maintain TCF-4/Wnt pathway activity. The reintroduction of FBXW7 abolished the oncogenic stimulation of miR-367 on TCF-4 activity, with Wnt signaling factors depression. In conclusion, our findings demonstrated the oncogenic roles of miR-367 exerting on the self-renewal ability of cancer stem-like cells through degrading the suppressive FBXW7, eventually helping to maintain Wnt signaling activation through a LIN28B/Let-7 dependent manner.