MAP2K1 | Cancer Genetics Web

Xu F, Song Y, Guo A
Anti-Apoptotic Effects of Docosahexaenoic Acid in IL-1β-Induced Human Chondrosarcoma Cell Death through Involvement of the MAPK Signaling Pathway.
Cytogenet Genome Res. 2019; 158(1):17-24 [PubMed] Related Publications

Osteoarthritis (OA) is a degenerative disease characterized by progressive articular cartilage destruction and joint marginal osteophyte formation with different degrees of synovitis. Docosahexaenoic acid (DHA) is an unsaturated fatty acid with anti-inflammatory, antioxidant, and antiapoptotic functions. In this study, the human chondrosarcoma cell line SW1353 was cultured in vitro, and an OA cell model was constructed with inflammatory factor IL-1β stimulation. After cells were treated with DHA, cell apoptosis was measured. Western blot assay was used to detect protein expression of apoptosis-related factors (Bax, Bcl-2, and cleaved caspase-3) and mitogen-activated protein kinase (MAPK) signaling pathway family members, including extracellular signal-regulated kinase (ERK), c-JUN N-terminal kinase (JNK), and p38 MAPK. Our results show that IL-1β promotes the apoptosis of SW1353 cells, increases the expression of Bax and cleaved caspase-3, and activates the MAPK signaling pathway. In contrast, DHA inhibits the expression of IL-1β, inhibits IL-1β-induced cell apoptosis, and has a certain inhibitory effect on the activation of the MAPK signaling pathway. When the MAPK signaling pathway is inhibited by its inhibitors, the effects of DHA on SW1353 cells are weakened. Thus, DHA enhances the apoptosis of SW1353 cells through the MAPK signaling pathway.

Related:

Colorectal (Bowel) Cancer

Bone Cancers

Chondrosarcoma

Jia H, Xu M, Bo Y, et al.
Ras-ERK1/2 signaling accelerates the progression of colorectal cancer via mediation of H2BK5ac.
Life Sci. 2019; 230:89-96 [PubMed] Related Publications

AIMS: Extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) is a key downstream gene of Ras pathway. Activation of Ras-ERK1/2 has been testified to be linked to the progression of diverse cancers. Nonetheless, whether Ras-ERK1/2-tumorigenic pathway is mediated by epigenetic factors remains indistinct. The purpose of the research attempted to disclose the functions of H2BK5ac in Ras-ERK1/2-evoked CRC cell phenotypes.
MATERIALS AND METHODS: Western blot assay was implemented for exploration of the relevancy between Ras-ERK1/2 and H2BK5ac. H2BK5Q was established and its functions in cell viability, colony formation and migration were appraised via utilizing MTT, soft-agar colony formation and Transwell assays. The mRNA and transcription of ERK1/2 downstream genes were estimated via RT-qPCR and ChIP assays. HDAC2 functions in SW48 cell phenotypes were evaluated after co-transfection with pEGFP-Ras
KEY FINDINGS: H2BK5ac expression was evidently repressed by Ras-ERK1/2 pathway in SW48 cells. Moreover, Ras-ERK1/2-elevated cell viability, the number of colonies and migration were both impeded by H2BK5ac. The mRNA and transcriptions of CYR61, IGFBP3, WNT16B, NT5E, GDF15 and CARD16 were both mediated by H2BK5ac. Additionally, HDAC2 silence overtly recovered H2BK5ac expression inhibited by Ras-ERK1/2, meanwhile abated Ras-ERK1/2-affected SW48 cell phenotypes. Beyond that, restrained H2BK5ac induced by Ras-ERK1/2 was concerned with MDM2-mediated ATF2 degradation.
SIGNIFICANCE: These investigations testified that Ras-ERK1/2 pathway affected SW48 cell phenotypes through repressing H2BK5ac expression. Otherwise, declined H2BK5ac might be linked to MDM2-mediated ATF2 degradation.

Related:

MDM2

Colorectal (Bowel) Cancer

GDF15

Zhan T, Ambrosi G, Wandmacher AM, et al.
MEK inhibitors activate Wnt signalling and induce stem cell plasticity in colorectal cancer.
Nat Commun. 2019; 10(1):2197 [PubMed] Free Access to Full Article Related Publications

In colorectal cancer (CRC), aberrant Wnt signalling is essential for tumorigenesis and maintenance of cancer stem cells. However, how other oncogenic pathways converge on Wnt signalling to modulate stem cell homeostasis in CRC currently remains poorly understood. Using large-scale compound screens in CRC, we identify MEK1/2 inhibitors as potent activators of Wnt/β-catenin signalling. Targeting MEK increases Wnt activity in different CRC cell lines and murine intestine in vivo. Truncating mutations of APC generated by CRISPR/Cas9 strongly synergize with MEK inhibitors in enhancing Wnt responses in isogenic CRC models. Mechanistically, we demonstrate that MEK inhibition induces a rapid downregulation of AXIN1. Using patient-derived CRC organoids, we show that MEK inhibition leads to increased Wnt activity, elevated LGR5 levels and enrichment of gene signatures associated with stemness and cancer relapse. Our study demonstrates that clinically used MEK inhibitors inadvertently induce stem cell plasticity, revealing an unknown side effect of RAS pathway inhibition.

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Liu J, Wang T, Creighton CJ, et al.
JNK
Nat Commun. 2019; 10(1):2148 [PubMed] Free Access to Full Article Related Publications

Mechanisms of lung squamous cell carcinoma (LSCC) development are poorly understood. Here, we report that JNK1/2 activities attenuate Lkb1-deficiency-driven LSCC initiation and progression through repressing ΔNp63 signaling. In vivo Lkb1 ablation alone is sufficient to induce LSCC development by reducing MKK7 levels and JNK1/2 activities, independent of the AMPKα and mTOR pathways. JNK1/2 activities is positively regulated by MKK7 during LSCC development. Pharmaceutically elevated JNK1/2 activities abates Lkb1 dependent LSCC formation while compound mutations of Jnk1/2 and Lkb1 further accelerate LSCC progression. JNK1/2 is inactivated in a substantial proportion of human LSCC and JNK1/2 activities positively correlates with survival rates of lung, cervical and head and neck squamous cell carcinoma patients. These findings not only determine a suppressive role of the stress response regulators JNK1/2 on LSCC development by acting downstream of the key LSCC suppresser Lkb1, but also demonstrate activating JNK1/2 activities as a therapeutic approach against LSCC.

Related:

Lung Cancer

STK11

Li D, Hao S, Zhang J
Long non-coding RNA UCA1 exerts growth modulation by miR-15a in human thyroid cancer TPC-1 cells.
Artif Cells Nanomed Biotechnol. 2019; 47(1):1815-1822 [PubMed] Related Publications

Thyroid cancer is widely diagnosed as malignancy in endocrine system. This study attempted to validate UCA1 possessed modulatory function on cell proliferation and epithelial mesenchymal transition (EMT) in human thyroid cancer cell line TPC-1. Ectopic expression of UCA1 was induced in TPC-1 cells by transfection. CCK-8 assays were employed to value cell viability. Cell apoptosis analysis was conducted through flow cytometry. We found that overexpressed UCA1 strongly promoted cell proliferation. However, the knockdown of UCA1 suppressed cell proliferation and induced obvious cell apoptosis. Besides, cell EMT was promoted by overexpressed UCA1 and was inhibited by the knockdown of UCA1. Further study revealed that miR-15a level in TPC-1 cells was suppressed by overexpressed UCA1. Simultaneous overexpression of UCA1 and miR-15a partly alleviated UCA1-induced growth, identifying that miR-15a was a possible target of UCA1. At last, the Hippo and JNK signal pathways were activated by overexpressed UCA1 but were then weakened by the adding of miR-15a. In conclusion, our study revealed UCA1/miR-15a axis implicated in thyroid cancer cells EMT, exposing a novel mechanism of thyroid cancer progression.

Related:

MicroRNAs

Thyroid Cancer

Sale MJ, Balmanno K, Saxena J, et al.
MEK1/2 inhibitor withdrawal reverses acquired resistance driven by BRAF
Nat Commun. 2019; 10(1):2030 [PubMed] Free Access to Full Article Related Publications

Acquired resistance to MEK1/2 inhibitors (MEKi) arises through amplification of BRAF

Related:

BRAF

KRAS

MAPK1

Zhang Q, Lu S, Li T, et al.
ACE2 inhibits breast cancer angiogenesis via suppressing the VEGFa/VEGFR2/ERK pathway.
J Exp Clin Cancer Res. 2019; 38(1):173 [PubMed] Free Access to Full Article Related Publications

BACKGROUND: Breast cancer angiogenesis is key for metastasis and predicts a poor prognosis. Angiotensin-converting enzyme 2 (ACE2), as a member of the renin-angiotensin system (RAS), was reported to restrain the progression of hepatocellular carcinoma (HCC) and non-small cell lung cancer (NSCLC) through inhibiting angiogenesis. However, the relationship between ACE2 and breast cancer angiogenesis remains unclear.
METHODS: The prognosis and relative gene selection were analysed using the GEPIA, GEO, TCGA and STRING databases. ACE2 expression in breast cancer tissue was estimated by reverse transcription-quantitative polymerase chain reaction (qPCR). Breast cancer cell migration, proliferation and angiogenesis were assessed by Transwell migration, proliferation, tube formation, and wound healing assays. The expression of vascular endothelial growth factor A (VEGFa) was detected by qPCR and Western blotting. The phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2), mitogen-activated protein kinase 1/2 (MEK1/2), and extracellular signal-regulated protein kinase 1/2 (ERK1/2) was examined by Western blotting. Breast cancer metastasis and angiogenesis in vivo were measured using a zebrafish model.
RESULTS: ACE2 was downregulated in breast cancer patients. Patients with higher ACE2 expression had longer relapse-free survival (RFS). In vitro, ACE2 inhibited breast cancer migration. Meanwhile, ACE2 in breast cancer cells inhibited human umbilical vascular endothelial cell (HUVEC) proliferation, tube formation and migration. In the zebrafish model, ACE2 inhibited breast cancer cell metastasis, as demonstrated by analyses of the number of disseminated foci and the metastatic distance. Neo-angiogenesis was also decreased by ACE2. ACE2 downregulated the expression of VEGFa in breast cancer cells. Furthermore, ACE2 in breast cancer cells inactivated the phosphorylation of VEGFR2, MEK1/2, and ERK1/2 in HUVECs.
CONCLUSIONS: Our findings suggest that ACE2, as a potential resister to breast cancer, might inhibit breast cancer angiogenesis through the VEGFa/VEGFR2/ERK pathway.
TRIAL REGISTRATION: Retrospectively registered.

Related:

Breast Cancer

Angiogenesis and Cancer

VEGFA

Kang FC, Wang SC, So EC, et al.
Propofol may increase caspase and MAPK pathways, and suppress the Akt pathway to induce apoptosis in MA‑10 mouse Leydig tumor cells.
Oncol Rep. 2019; 41(6):3565-3574 [PubMed] Related Publications

In the western world, there is an increasing trend of occurrence in testicular cancer. Treatment of malignant testicular cancer is primarily combined surgery with various chemical drugs. Propofol has been frequently used as an anesthetic and sedative induction agent, which could modulate different γ‑aminobutyric acid receptors in the central nervous system. Studies demonstrated that propofol activates endoplasmic reticulum stress to induce apoptosis in lung cancer. However, it remains elusive whether propofol regulates caspase and/or mitogen‑activated protein kinase (MAPK) pathways to induce apoptosis in Leydig tumor cells. In the present study, MA‑10 mouse Leydig tumor cells were treated with propofol, and possible signal pathways associated with apoptosis were investigated. Results demonstrated that increasing dosage of propofol (300‑600 µM) for 24 h significantly decreased cell viability in MA‑10 cells (P<0.05). In flow cytometry analysis, the amount of sub‑G1 phase cell numbers in MA‑10 cells was significantly increased by propofol (P<0.05). Additionally, Annexin V/propidium iodide double staining further confirmed that propofol could induce MA‑10 cell apoptosis. Furthermore, cleaved caspase‑8, ‑9 and ‑3, and/or poly(ADP‑ribose) polymerase were significantly activated following treatment of propofol in MA‑10 cells. In addition, c‑Jun N‑terminal kinase, extracellular signal‑regulated kinase 1/2, and p38 were significantly activated by propofol in MA‑10 cells (P<0.05), indicating that propofol may induce apoptosis through the MAPK pathway. Additionally, propofol diminished the phosphorylation of Akt to activate apoptosis in MA‑10 cells. In conclusion, propofol may induce MA‑10 cell apoptosis by activating caspase and MAPK pathways, and inhibiting the Akt pathway in MA‑10 cells, demonstrating that propofol may be a potential anticancer agent against Leydig cell cancer.

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Sur S, Nakanishi H, Steele R, Ray RB
Depletion of PCAT-1 in head and neck cancer cells inhibits tumor growth and induces apoptosis by modulating c-Myc-AKT1-p38 MAPK signalling pathways.
BMC Cancer. 2019; 19(1):354 [PubMed] Free Access to Full Article Related Publications

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) represents one of the most common malignancies worldwide with a high mortality rate mainly due to lack of early detection markers, frequent association with metastasis and aggressive phenotype. Recently, long non-coding RNAs (lncRNAs) have been shown to have important regulatory roles in human cancers. The lncRNA prostate cancer-associated transcript 1 (PCAT-1) showed potential oncogenic roles in different cancers, however its role in HNSCC is not known. In this study, we evaluated the role of the PCAT-1 in HNSCC.
METHODS: The expression of PCAT-1 was measured by quantitative real-time PCR in 23 paired human HNSCC tissues and adjacent non-tumor tissue specimens. Cell proliferation after depleting PCAT-1 was determined. Effect of PCAT-1 depletion in HNSCC cell lines was determined by qRT-PCR and Western blot analyses. Finally, JHU029 HNSCC cells was implanted subcutaneously into athymic nude mice and therapeutic potential of PCAT-1 was investigated.
RESULTS: Up-regulation of PCAT-1 in TCGA dataset of HNSCC was noted. We also observed increased expression of PCAT-1 in archived HNSCC patient samples as compared to adjacent non-tumor tissues. Knockdown of PCAT-1 significantly reduced cell proliferation in HNSCC cell lines. Mechanistic study revealed significant down regulation of c-Myc and AKT1 gene in both RNA and protein levels upon knockdown of PCAT-1. We observed that c-Myc and AKT1 positively correlate with PCAT-1 expression in HNSCC. Further, we observed activation of p38 MAPK and apoptosis signal-regulating kinase 1 upon knockdown of PCAT-1 which induces Caspase 9 and PARP mediated apoptosis. Targeted inhibition of PCAT-1 regresses tumor growth in nude mice.
CONCLUSION: Together our data demonstrated an important role of the PCAT-1 in HNSCC and might serve as a target for HNSCC therapy.

Related:

Head and Neck Cancers - Molecular Biology

Head and Neck Cancers

AKT1

Chen M, Xu M, Zhu C, et al.
Sirtuin2 enhances the tumoricidal function of liver natural killer cells in a mouse hepatocellular carcinoma model.
Cancer Immunol Immunother. 2019; 68(6):961-971 [PubMed] Related Publications

Hepatocellular carcinoma (HCC) is the third most lethal cancer in the world. Natural killer (NK) cell-mediated immunity is crucial for tumor surveillance and therapy. Characterization of the regulatory mechanisms of NK cell function is important for developing novel immunotherapies against HCC. In this study, we used a chemical-induced mouse HCC model to identify the upregulation of Sirtuin2 (SIRT2) in liver NK cells. In particular, SIRT2 was predominantly expressed in liver CD94

Related:

Cytokines

Chen MK, Peng CC, Maner RS, et al.
Geniposide ameliorated fluoxetine-suppressed neurite outgrowth in Neuro2a neuroblastoma cells.
Life Sci. 2019; 226:1-11 [PubMed] Related Publications

AIM: Fluoxetine (FXT), a selective serotonin reuptake inhibitor (SSRI), is one of the most common psychiatric medications clinically prescribed; while over-produced serotonin may suppress neurite development. The role of major iridoids like geniposide (GPS) and genipin (GNP) from Gardenia jasminoides Ellis fruit (family Rubiaceae) in ameliorating the anti-neurite outgrowth effect of FXT is poorly understood. In this study, the effects of these iridoids on FXT-suppressed neurite outgrowth in Neuro2a neuroblastoma cells were investigated.
MAIN METHODS: Neuro2a cells were treated with FXT and GPS. The effect of GPS-FXT co-treatment on neurite outgrowth was observed using inverted phase-contrast microscope imaging system, while neurite outgrowth markers - microtubule-associated protein-2 (MAP2) and growth-associated protein 43 (GAP43) were analyzed using RT-PCR, Western blot and immunofluorescence staining. The transcription factor-cAMP response element binding (CREB), and signaling pathways - mitogen-activated protein kinase (MAPK) and protein kinase B/mammalian target of rapamycin (AKT/mTOR) were also analyzed with the help of Western blot.
KEY FINDINGS: The results showed that FXT decreased the neurite outgrowth in Neuro2a cells and also downregulated gene and protein expression of MAP2 and GAP43. It also downregulated the protein expression of phosphorylated-CREB, MAPK, and AKT/mTOR signaling pathways. In contrast, GPS counteracted the effects of FXT. GPS-FXT co-treatment increased the percentage of neurite-bearing cells by 3.6-fold at 200 μM as compared to FXT treatment only.
SIGNIFICANCE: This study has provided the possible molecular mechanism showing how FXT exerted its detrimental side-effects on the neurite differentiation, and via the same mechanism how GPS attenuated these side effects.

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MTOR

Zhang J, Hou L, Liang R, et al.
CircDLST promotes the tumorigenesis and metastasis of gastric cancer by sponging miR-502-5p and activating the NRAS/MEK1/ERK1/2 signaling.
Mol Cancer. 2019; 18(1):80 [PubMed] Free Access to Full Article Related Publications

BACKGROUND: Accumulating evidence shows that, the dysregulation of circular RNAs (circRNAs) is associated with the progression of multiple malignancies. But, the underlying mechanisms by which has_circ_0032627 (circDLST) contributed to gastric cancer (GC) remain undocumented.
METHODS: The expression and cellular localization of circDLST and its association with clinicopathological characteristics and prognosis in patients with GC was analysed by using fluorescence in situ hybridization. Gain- and loss-of-function experiments as well as a subcutaneous xenograft tumor model and a liver metastasis model from orthotopic implantation of GC tissues were conducted to assess the role of circDLST in GC cells. CircDLST specific binding with miR-502-5p was confirmed by dual luciferase gene report, RNA immunoprecipitation (RIP) assays and RIP-miRNA expression profiling. qRT-PCR and Western blot analysis was used to detect the effects of circDLST on miR-502-5p-mediated NRAS/MEK1/ERK1/2 signaling in GC cells.
RESULTS: The expression levels of circDLST were dramatically elevated in GC tissues as compared with the adjacent normal tissues, and acted as an independent prognostic factor of poor survival in patients with GC. Knockdown of circDLST inhibited the cell viability, colony formation, DNA synthesis, cell invasion and liver metastasis in vitro and in vivo, whereas overexpression of circDLST had the opposite effects. Furthermore, circDLST was co-localized with miR-502-5p in the cytoplasm of GC cells, and acted as a sponge of miR-502-3p in GC cells, which abrogated the tumor promoting effects of circDLST by inactivating the NRAS/MEK1/ERK1/2 signaling in GC cells.
CONCLUSION: CircDLST promotes the tumorigenesis and metastasis of GC cells by sponging miR-502-5p to activate the NRAS/MEK1/ERK1/2 signaling.

Related:

MicroRNAs

Stomach Cancer

Gastric Cancer

NRAS

Ding Q, Li X, Sun Y, Zhang X
Schizandrin A inhibits proliferation, migration and invasion of thyroid cancer cell line TPC-1 by down regulation of microRNA-429.
Cancer Biomark. 2019; 24(4):497-508 [PubMed] Related Publications

OBJECTIVE: Schizandrin A (SchA) exerts anticancer potential. However, the effects of SchA on thyroid cancer (TC) have not been clear illuminated. Therefore, we investigated the effects of SchA on TC cell line TPC-1 and the underlying mechanisms.
METHODS: TPC-1 cells were treated with SchA and/or transfected with miR-429 mimic, anti-miR-429 and their corresponding negative controls (NC). Cell viability, proliferation, migration, invasion and cell apoptosis were examined by CCK-8 assay, bromodeoxyuridine, modified two-chamber migration assay, Millicell Hanging Cell Culture and flow cytometry analysis, respectively. The expression of miR-429, p16, Cyclin D1, cyclin-dependent kinases 4 (CDK4), matrix metalloprotein (MMP)-2, MMP-9 and Vimentin was detected by qRT-PCR. All protein expression was examined by western blot.
RESULTS: SchA inhibited cell proliferation, metastasis and induced cell apoptosis. Moreover, SchA negatively regulated miR-429 expression. Treatment with miR-429 mimic and SchA reversed the results led by SchA and NC. Furthermore, the phosphorylation β-catenin, mitogen-activated protein kinase (MEK) and extracellular signal-regulated kinase (ERK) were statistically down-regulated by SchA while co-treatment with miR-429 mimic and SchA led to the opposite trend. Moreover, miR-429 knockdown showed contrary results.
CONCLUSION: SchA inhibits cell proliferation, migration, invasion and inactivates Wnt/β-catenin and MEK/ERK signaling pathways by down regulating miR-429.

Related:

MicroRNAs

Thyroid Cancer

Kawazoe T, Taniguchi K
The Sprouty/Spred family as tumor suppressors: Coming of age.
Cancer Sci. 2019; 110(5):1525-1535 [PubMed] Free Access to Full Article Related Publications

The Ras/Raf/ERK pathway is one of the most frequently dysregulated signaling pathways in various cancers. In some such cancers, Ras and Raf are hotspots for mutations, which cause continuous activation of this pathway. However, in some other cancers, it is known that negative regulators of the Ras/Raf/ERK pathway are responsible for uncontrolled activation. The Sprouty/Spred family is broadly recognized as important negative regulators of the Ras/Raf/ERK pathway, and its expression is downregulated in many malignancies, leading to hyperactivation of the Ras/Raf/ERK pathway. After the discovery of this family, intensive research investigated the mechanism by which it suppresses the Ras/Raf/ERK pathway and its roles in developmental and pathophysiological processes. In this review, we discuss the complicated roles of the Sprouty/Spred family in tumor initiation, promotion, and progression and its future therapeutic potential.

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Shi DB, Ma RR, Zhang H, et al.
GAGE7B promotes tumor metastasis and growth via activating the p38δ/pMAPKAPK2/pHSP27 pathway in gastric cancer.
J Exp Clin Cancer Res. 2019; 38(1):124 [PubMed] Free Access to Full Article Related Publications

BACKGROUND: Gastric cancer is the second most common cause of cancer-related mortality; thus, the mechanisms underlying tumor metastasis and growth in gastric cancer need to be extensively explored.
METHODS: Differentially expressed genes were examined in gastric cancer samples with lymph node metastasis (LNM) and without LNM using mRNA microarray and RT-qPCR. The effects of G antigen 7B (GAGE7B) on the metastasis, growth, and angiogenesis of gastric cancer were investigated in vitro and in vivo. GAGE7B protein expression was detected by immunohistochemical (IHC) analysis. Microarray, RT-qPCR, and western blot assays were performed to detect downstream target genes of GAGE7B. Dual-luciferase reporter and western blot assays were used to identify miRNAs that could negatively regulate GAGE7B.
RESULTS: GAGE7B was significantly overexpressed in samples with LNM. High expression levels of GAGE7B were associated with advanced clinical stage and poor patient survival. GAGE7B dramatically enhanced the metastasis, growth, and angiogenesis ability of gastric cancer. GAGE7B was further demonstrated to promote the progression of gastric cancer by activating the p38δ/pMAPKAPK2/pHSP27 pathway. However, the GAGE7B-induced p38δ/pMAPKAPK2/pHSP27 pathway was inactivated by miR-30c, as the expression levels of both GAGE7B and p38δ were found to be directly suppressed by miR-30c. Intriguingly, GAGE7B was found to be a ceRNA for p38δ, as it activated the p38δ/pMAPKAPK2/pHSP27 pathway by competitively binding miR-30c.
CONCLUSIONS: GAGE7B may serve as a prognostic indicator in gastric cancer. GAGE7B significantly promotes gastric cancer progression by upregulating the p38δ/pMAPKAPK2/pHSP27 pathway, but it is negatively regulated by miR-30c. GAGE7B and miR-30c may be potential therapeutic targets in gastric cancer.

Related:

Angiogenesis and Cancer

Chronic Myeloid Leukemia (CML)

Stomach Cancer

Gastric Cancer

HSPB1

Uchida E, Suwa S, Yoshimoto R, et al.
TOPK is regulated by PP2A and BCR/ABL in leukemia and enhances cell proliferation.
Int J Oncol. 2019; 54(5):1785-1796 [PubMed] Related Publications

Although treatment of chronic myeloid leukemia (CML) has improved with the development of tyrosine kinase inhibitors (TKIs), patients develop fatal blast crisis (BC) whilst receiving TKI treatment. Alternative treatments for cases resistant to TKIs are required. A serine/threonine protein kinase, T‑lymphokine‑activated killer cell‑originated protein kinase (TOPK), is highly expressed in various malignant tumors. Binding of peptides to human leukocyte antigen was assessed via mass spectrometry in K562 CML cells. TOPK expression was assessed in various CML cell lines and in clinical samples obtained from patients with CML using reverse transcription‑quantitative polymerase chain reaction and western blot assays. It was observed that TOPK was expressed abundantly in BCR/ABL‑positive cell lines and at significantly higher levels in CML clinical samples compared with healthy donor samples. Overexpression of BCR/ABL or the presence of its inhibitor imatinib upregulated and downregulated TOPK expression, respectively, indicating that TOPK may be a target of BCR/ABL. TOPK inhibitor OTS514 suppressed proliferation of BCR/ABL‑positive cell lines and colony formation of CD34‑positive cells from patients with CML compared with lymphoma patients without bone marrow involvement. Furthermore, phosphorylation of TOPK was increased by protein phosphatase 2A (PP2A) inhibitor okadaic acid and was decreased in the presence of PP2A activator FTY720 compared with untreated samples. As constitutive BCR/ABL activity and inhibition of PP2A are key mechanisms of CML development, TOPK may be a crucial signaling molecule for this disease. Inhibition of TOPK may control disease status of CML, even in cases resistant to TKIs.

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CML - Molecular Biology

Ko YC, Hu CY, Liu ZH, et al.
Cytarabine-Resistant
Int J Mol Sci. 2019; 20(5) [PubMed] Free Access to Full Article Related Publications

Internal tandem duplication of FLT3 juxtamembrane domain (FLT3-ITD)-positive acute myeloid leukemia (AML) leads to poor clinical outcomes after chemotherapy. We aimed to establish a cytarabine-resistant line from

Related:

Cytarabine

Acute Myeloid Leukemia (AML)

TP53

FLT3

Xu M, Xu S
PBK/TOPK overexpression and survival in solid tumors: A PRISMA-compliant meta-analysis.
Medicine (Baltimore). 2019; 98(10):e14766 [PubMed] Free Access to Full Article Related Publications

BACKGROUND: The prognostic significance of PBK/TOPK overexpression in solid tumors remains controversial. Therefore, we carried out a meta-analysis to evaluate the impact of PBK/TOPK overexpression in solid tumors on patients' overall survival (OS) and disease-free survival (DFS).
METHODS: Relevant articles were identified through searching the PubMed, Embase and Web of Science up to May 2017. The pooled hazard ratio (HR) with 95% confidence interval (CI) was used to estimate the effects.
RESULTS: In this meta-analysis, 12 studies involving 1571 participants were included, PBK/TOPK overexpression was significantly associated with poor OS (pooled HR = 1.91, 95%CI = 1.22-3.00, P = .005) and short DFS (pooled HR = 1.95, 95%CI = 1.46-2.58, P < .001).
CONCLUSIONS: PBK/TOPK overexpression was associated with poor survival in human solid tumors which may be a valuable prognosis biomarker and a potential therapeutic target of solid tumors.

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Soni S, Anand P, Padwad YS
MAPKAPK2: the master regulator of RNA-binding proteins modulates transcript stability and tumor progression.
J Exp Clin Cancer Res. 2019; 38(1):121 [PubMed] Free Access to Full Article Related Publications

The p38 mitogen-activated protein kinase (p38MAPK) pathway has been implicated in a variety of pathological conditions including inflammation and metastasis. Post-transcriptional regulation of genes harboring adenine/uridine-rich elements (AREs) in their 3'-untranslated region (3'-UTR) is controlled by MAPK-activated protein kinase 2 (MAPKAPK2 or MK2), a downstream substrate of the p38MAPK. In response to diverse extracellular stimuli, MK2 influences crucial signaling events, regulates inflammatory cytokines, transcript stability and critical cellular processes. Expression of genes involved in these vital cellular cascades is controlled by subtle interactions in underlying molecular networks and post-transcriptional gene regulation that determines transcript fate in association with RNA-binding proteins (RBPs). Several RBPs associate with the 3'-UTRs of the target transcripts and regulate their expression via modulation of transcript stability. Although MK2 regulates important cellular phenomenon, yet its biological significance in tumor progression has not been well elucidated till date. In this review, we have highlighted in detail the importance of MK2 as the master regulator of RBPs and its role in the regulation of transcript stability, tumor progression, as well as the possibility of use of MK2 as a therapeutic target in tumor management.

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Kang M, Park SH, Park SJ, et al.
p44/42 MAPK signaling is a prime target activated by phenylethyl resorcinol in its anti-melanogenic action.
Phytomedicine. 2019; 58:152877 [PubMed] Related Publications

BACKGROUND: Melanin plays a crucial role in protecting human skin against exposure to ultraviolet (UV) radiation. However, its overproduction induces hyperpigmentation disorders of the skin.
PURPOSE: To investigate effects of phenylethyl resorcinol as one resorcinol derivative on melanogenesis and its mechanisms using B16F10 mouse melanoma cells and human epidermal melanocytes.
METHODS: Effects of phenylethyl resorcinol on melanogenesis and its mechanism of action were examined using several in vitro assays (i.e., cell survival, melanin content, cellular tyrosinase activity, real-time PCR analysis, luciferase-reporter assay, Western blot analysis, and ELISAs for cyclic AMP (cAMP), protein kinase A (PKA), cAMP response element binding (CREB) protein, and mitogen-activated protein kinases (MAPKs)).
RESULTS: Phenylethyl resorcinol reduced both melanin content and tyrosinase activity in these cells. Phenylethyl resorcinol also suppressed tyrosinase activity in cell-free tyrosinase enzyme assay. Although phenylethyl resorcinol decreased mRNA levels of tyrosinase and tyrosinase-related protein (TRP)-2, it did not affect mRNA levels of melanogenic gene microphthalmia-associated transcriptional factor (MITF) or TRP-1. Phenylethyl resorcinol had no effects on cAMP signaling or NF-κB signaling based on results of cyclic AMP response element (CRE)-luciferase reporter assay, cAMP production, protein kinase A (PKA) activity, Western blot assays for phosphorylated CRE-binding protein (CREB), NF-κB-luciferase reporter assay, and Western blot assays for phosphorylated NF-κB. However, phenylethyl resorcinol induced activation of activator protein-1 (AP-1) signaling. Specifically, phenylethyl resorcinol increased AP-1 reporter activity and increased phosphorylation of p44/42 MAPK, but not p38 MAPK or c-Jun N-terminal kinase (JNK). MEK1/2 and Src, upstream molecules of p44/42 MAPK were also phosphorylated by phenylethyl resorcinol. In addition, phenylethyl resorcinol-induced decreases in melanin content, tyrosinase activity, and MITF protein levels were attenuated by PD98059, a p44/42 MAPK inhibitor.
CONCLUSION: These data indicate that the anti-melanogenic activity of phenylethyl resorcinol is mediated by activation of p44/42 MAPK, indicating that phenylethyl resorcinol may be a potential therapeutic agent for treating hyperpigmentation skin disorders.

Related:

Melanoma

MITF

Zhang Y, He Y, Lu LL, et al.
miRNA-192-5p impacts the sensitivity of breast cancer cells to doxorubicin via targeting peptidylprolyl isomerase A.
Kaohsiung J Med Sci. 2019; 35(1):17-23 [PubMed] Related Publications

The administration of doxorubicin (DOX) is one of the first-line treatments of breast cancer. However, acquisition of resistance remains the major obstacle restricting the clinical application of DOX. MicroRNAs (miRNAs) are small, noncoding RNAs which play crucial role in epigenetic regulation. Recent studies have shown that miRNAs are associated with tumor chemoresistance. Here we aim to explore the role of miRNA-192-5p in resistance to DOX in breast cancer cells. Normal human breast epithelial cell line MCF-10A, breast cancer cell line Michigan Cancer Foundation-7 (MCF-7), and DOX-resistant breast cancer cell line MCF-7/ADR were used here. The expression of miR-192-5p was examined by qPCR, and the expression of peptidylprolyl isomerase A (PPIA) was examined by qPCR and Western blot. The effects of miR-192-5p overexpression on the sensitivity to DOX were confirmed by Methylthiazolyldiphenyl-tetrazolium bromide (MTT) and Annexin-V/PI assay. Downstream molecular mechanisms, including PPIA, BAD, CASP9, Bcl-2, and c-Jun N-terminal kinase (JNK) activation, were detected by Western blot and qPCR. Luciferase reporter assay was used to validate the association between miR-192-5p and PPIA. miR-192-5p was downregulated while PPIA was upregulated in MCF-7/ADR cells. Functionally, miR-192-5p overexpression increased sensitivity to DOX by promoting cell apoptosis. Mechanistically, miR-192-5p overexpression performed its function by activating JNK, augmenting BAD and caspase9 expression, and suppressing Bcl-2 and PPIA expression. Luciferase assay validated that PPIA was a direct target of miR-192-5p. miR-192-5p sensitizes breast cancer cells to DOX by targeting PPIA, suggesting that miR-192-5p might serve as a novel target for reversing DOX resistance and controlling breast tumor growth.

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Wang G, Yin L, Peng Y, et al.
Insulin promotes invasion and migration of KRAS
Cell Prolif. 2019; 52(3):e12575 [PubMed] Related Publications

OBJECTIVES: Hyperinsulinemia is a risk factor for pancreatic cancer, but the function of insulin in carcinogenesis is unclear, so this study aimed to elucidate the carcinogenic effects of insulin and the synergistic effect with the KRAS mutation in the early stage of pancreatic cancer.
MATERIALS AND METHODS: A pair of immortalized human pancreatic duct-derived cells, hTERT-HPNE E6/E7/st (HPNE) and its oncogenic KRAS
RESULTS: The migration and invasion ability of HPNE cells was increased after the introduction of the mutated KRAS gene, together with an increased expression of MMP-2. These effects were further enhanced by the simultaneous administration of insulin. The use of MMP-2 siRNA confirmed that MMP-2 was involved in the regulation of cell invasion. Furthermore, there was a concentration- and time-dependent increase in gelatinase activity after insulin treatment, which could be reversed by an insulin receptor tyrosine kinase inhibitor (HNMPA-(AM)
CONCLUSIONS: Taken together, these results suggest that insulin induced migration and invasion in HPNE and HPNE-mut-KRAS through PI3K/AKT and ERK1/2 activation, with MMP-2 gelatinolytic activity playing a vital role in this process. These findings may provide a new therapeutic target for preventing carcinogenesis and the evolution of pancreatic cancer with a background of hyperinsulinemia.

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MMP2

Cancer of the Pancreas

Pancreatic Cancer

KRAS

Lee D, Kim KH, Lee WY, et al.
Multiple Targets of 3-Dehydroxyceanothetric Acid 2-Methyl Ester to Protect Against Cisplatin-Induced Cytotoxicity in Kidney Epithelial LLC-PK1 Cells.
Molecules. 2019; 24(5) [PubMed] Free Access to Full Article Related Publications

Chronic exposure to cisplatin, a potent anticancer drug, causes irreversible kidney damage. In this study, we investigated the protective effect and mechanism of nine lupane- and ceanothane-type triterpenoids isolated from jujube (

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CASP3

Cisplatin

Ma Y, Lai W, Zhao M, et al.
Plastin 3 down-regulation augments the sensitivity of MDA-MB-231 cells to paclitaxel via the p38 MAPK signalling pathway.
Artif Cells Nanomed Biotechnol. 2019; 47(1):685-695 [PubMed] Related Publications

Plastin 3 (PLS3) overexpression may serve as a marker for predicting chemotherapeutic outcomes in drug-resistant cancer cells, but the mechanism is unclear. Herein, we show that the down-regulation of PLS3 by PLS3 gene silencing augments the sensitivity of MDA-MB-231 triple-negative breast cancer cells to paclitaxel. Interestingly, a low concentration of paclitaxel was able to induce strong apoptosis in the PLS3-silenced cells. Further study revealed that p38 MAPK signalling was responsible for the increased sensitivity to paclitaxel in these cells, as the p38 MAPK inhibitor SB203580 impaired the changes mediated by PLS3 down-regulation in response to paclitaxel. Therefore, our study identifies PLS3 as a potential target for enhancing the p38 MAPK-mediated apoptosis induced by paclitaxel. Unlike paclitaxel, Abraxane was unable to induce strong apoptosis in the PLS3-silenced cells. As PLS3 was found to be involved in the process of endocytosis in breast cancer cells, the reliance of cellular Abraxane uptake on this process may render it not as efficient as paclitaxel in PLS3-depleted tumour cells. The finding that PLS3 could be a critical regulator of paclitaxel sensitivity may have important implications for breast cancer chemotherapy.

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Colorectal (Bowel) Cancer

Breast Cancer

Paclitaxel

Ku KE, Choi N, Oh SH, et al.
Src inhibition induces melanogenesis in human G361 cells.
Mol Med Rep. 2019; 19(4):3061-3070 [PubMed] Free Access to Full Article Related Publications

The Src kinase family (SKF) includes non‑receptor tyrosine kinases that interact with many cellular cytosolic, nuclear and membrane proteins, and is involved in the progression of cellular transformation and oncogenic activity. However, there is little to no evidence on the effect of SKF or its inhibitors on melanogenesis. Therefore, the present study investigated whether C‑terminal Src kinase inhibition can induce melanogenesis and examined the associated signaling pathways and mRNA expression of melanogenic proteins. First, whether stimulators of melanogenesis, such as ultraviolet B and α‑melanocyte‑stimulating hormone, can dephosphorylate Src protein was evaluated, and the results revealed that SU6656 and PP2 inhibited the phosphorylation of Src in G361 cells. Src inhibition by these chemical inhibitors induced melanogenesis in G361 cells and upregulated the mRNA expression levels of melanogenesis‑associated genes encoding microphthalmia‑associated transcription factor, tyrosinase‑related protein 1 (TRP1), TRP2, and tyrosinase. In addition, Src inhibition by small interfering RNA induced melanogenesis and upregulated the mRNA expression levels of melanogenesis‑associated genes. As the p38 mitogen‑activated protein kinase (MAPK) and cyclic adenosine monophosphate response element binding (CREB) pathways serve key roles in melanogenesis, the present study further examined whether Src mediates melanogenesis via these pathways. As expected, Src inhibition via SU6656 or PP2 administration induced the phosphorylation of p38 or CREB, as determined by western blotting analysis, and increased the levels of phosphorylated p38 or CREB, as determined by immunofluorescence staining. In addition, the induced pigmentation and melanin content of G361 cells by Src inhibitors was significantly inhibited by p38 or CREB inhibitors. Taken together, these data indicate that Src is associated with melanogenesis, and Src inhibition induces melanogenesis via the MAPK and CREB pathways in G361 cells.

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Melanoma

Li Y, Xiao F, Li W, et al.
Overexpression of Opa interacting protein 5 increases the progression of liver cancer via BMPR2/JUN/CHEK1/RAC1 dysregulation.
Oncol Rep. 2019; 41(4):2075-2088 [PubMed] Free Access to Full Article Related Publications

Opa interacting protein 5 (OIP5) overexpression is associated with human carcinoma. However, its biological function, underlying mechanism and clinical significance in liver cancer remain unknown. In the present study, the effects of OIP5 expression on liver cancer, and the mechanisms regulating these effects, were investigated. OIP5 expression was measured in human hepatocellular carcinoma (HCC) tissues and liver cancer cell lines. The effect of OIP5 knockdown on tumorigenesis was also detected in nude mice, and differentially‑expressed genes (DEGs) were identified and their biological functions were identified. The results indicated that OIP5 expression was significantly upregulated in HCC tissues and four liver cancer cell lines (P<0.01). Increased OIP5 protein expression significantly predicted reduced survival rate of patients with HCC (P<0.01). OIP5 knockdown resulted in the suppression of proliferation and colony forming abilities, cell cycle arrest at the G0/G1 or G2/M phases, and promotion of cell apoptosis. A total of 628 DEGs, including 87 upregulated and 541 downregulated genes, were identified following OIP5 knockdown. Functional enrichment analysis indicated that DEGs were involved in 'RNA Post‑Transcriptional Modification, Cancer and Organismal Injury and Abnormalities'. Finally, OIP5 knockdown in Huh7 cells dysregulated bone morphogenetic protein receptor type 2/JUN/checkpoint kinase 1/Rac family small GTPase 1 expression. In conclusion, the overall results demonstrated the involvement of OIP5 in the progression of liver cancer and its mechanism of action.

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Liver Cancer

RAC1

Wan XB, Wang AQ, Cao J, et al.
Relationships among
World J Gastroenterol. 2019; 25(7):808-823 [PubMed] Free Access to Full Article Related Publications

BACKGROUND: The RAS/RAF/MEK/ERK and PI3K/AKT/mTOR signaling pathways all belong to mitogen-activated protein kinase (MAPK) signaling pathways, Mutations in any one of the upstream genes (such as the
AIM: To investigate the
METHODS: Colorectal cancer tissue specimens from 196 patients were analyzed for
RESULTS: Of the 196 patients, 62 (32%) carried mutations in codon 12 (53/62) or codon 13 (9/62) in exon 2 of the

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BRAF

KRAS

Han SE, Park CH, Nam-Goong IS, et al.
Anticancer Effects of Baicalein in FRO Thyroid Cancer Cells Through the Up-regulation of ERK/p38 MAPK and Akt Pathway.
In Vivo. 2019 Mar-Apr; 33(2):375-382 [PubMed] Free Access to Full Article Related Publications

BACKGROUND/AIM: The aim of the study was to evaluate the anticancer effects of baicalein in FRO anaplastic thyroid cancer (ATC) cells.
MATERIALS AND METHODS: FRO cells were treated with baicalein and viability was measured by the MTT assay. Cell apoptosis was observed by staining with Hoechst dye. The expression of apoptotic proteins (Bax, Bcl-2, PARP, cytochrome c, and caspase-3) and the inflammatory protein Cox-2 and the phosphorylation of MAPKs and Akt were determined by western blot.
RESULTS: Treatment with baicalein inhibited cell proliferation in a time-dependent manner and increased DNA fragmentation and apoptosis in FRO cells. Baicalein at 50 and 100 μM inhibited the expression of Bax, PARP, cytochrome c, cleaved caspase-3, and Cox-2, and increased the expression of Bcl-2. Baicalein increased the phosphorylation of ERK, p38 MAPK, and Akt and decreased JNK phosphorylation.
CONCLUSION: Baicalein caused anticancer effects in FRO ATC cells through induction of apoptosis and regulation of the MAPK and Akt pathway.

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Chiang CH, Chung JG, Hsu FT
Regorefenib induces extrinsic/intrinsic apoptosis and inhibits MAPK/NF-κB-modulated tumor progression in bladder cancer in vitro and in vivo.
Environ Toxicol. 2019; 34(6):679-688 [PubMed] Free Access to Full Article Related Publications

The aim of the present study is to investigate anticancer effect and mechanism of regorafenib in bladder cancer in vitro and in vivo. Human bladder cancer TSGH 8301 cells were treated with regorafenib, NF-κB, AKT, or mitogen-activated protein kinase (MAPK) inhibitors for different time. The changes of cell viability, NF-κB activation, apoptotic signaling transduction, and expression of tumor progression-associated proteins were evaluated with MTT, NF-κB reporter gene assay, flow cytometry, and Western blotting assay. TSGH 8301 tumor bearing mice were established and treated with vehicle (140 μL of 0.1% DMSO) or regorafenib (10 mg/kg/day by gavage) for 15 days. The changes of tumor volume, body weight, NF-κB activation, MAPK activation, and tumor progression-associated proteins (MMP-9, XIAP, VEGF, and Cyclin-D1) after regorafenib treatment were evaluated with digital caliper, digital weight, and ex vivo Western blotting assay. Our results demonstrated NF-κB activation and protein levels of MMP-9, XIAP, VEGF, and Cyclin-D1 were significantly reduced by NF-κB (QNZ), ERK (PD98059), and P38 (SB203580) inhibitors. Regorafenib also significantly induced extrinsic and intrinsic apoptotic signaling transduction in bladder cancer in vitro. In addition, regorafenib significantly inhibited tumor growth, NF-κB, p38, ERK activation and expression of tumor progression-associated proteins in bladder cancer in vitro and in vivo. Taken together, these results proved that regorafenib not only induced apoptosis through extrinsic and intrinsic pathways and but suppressed MAPK/ NF-κB-modulated tumor progression in bladder cancer.

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