CA : A Cancer Journal for Clinicians

We report here the identification of α1 Na/K-ATPase as a major regulator of the proto-oncogene Src kinase and the role of this regulation in control of Warburg effect and tumor growth. Specifically, we discovered Y260 in α1 Na/K-ATPase as a Src-specific phosphorylation and binding site and that Y260 phosphorylation is required for Src-mediated signal transduction in response to a number of stimuli including EGF. As such, it enables a dynamic control of aerobic glycolysis. However, such regulation appears to be lost or attenuated in human cancers as the expression of Na/K-ATPase α1 was significantly decreased in prostate, breast and kidney cancers, and further reduced in corresponding metastatic lesions in patient samples. Consistently, knockdown of α1 Na/K-ATPase led to a further increase in lactate production and the growth of tumor xenograft. These findings suggest that α1 Na/K-ATPase works as a tumor suppressor and that a loss of Na/K-ATPase-mediated Src regulation may lead to Warburg phenotype in cancer.

/pdf/na-k-atpase-y260-phosphorylation-mediated-src-regulation-in-43lk9s248d.pdf

Na/K-ATPase Y260 Phosphorylation-mediated Src Regulation in Control of Aerobic Glycolysis and Tumor Growth

Liability to alcohol dependence (AD) is heritable, but little is known about its complex polygenic architecture or its genetic relationship with other disorders. To discover loci associated with AD and characterize the relationship between AD and other psychiatric and behavioral outcomes, we carried out the largest genome-wide association study to date of DSM-IV-diagnosed AD. Genome-wide data on 14,904 individuals with AD and 37,944 controls from 28 case-control and family-based studies were meta-analyzed, stratified by genetic ancestry (European, n = 46,568; African, n = 6,280). Independent, genome-wide significant effects of different ADH1B variants were identified in European (rs1229984; P = 9.8 × 10-13) and African ancestries (rs2066702; P = 2.2 × 10-9). Significant genetic correlations were observed with 17 phenotypes, including schizophrenia, attention deficit-hyperactivity disorder, depression, and use of cigarettes and cannabis. The genetic underpinnings of AD only partially overlap with those for alcohol consumption, underscoring the genetic distinction between pathological and nonpathological drinking behaviors.

/pdf/transancestral-gwas-of-alcohol-dependence-reveals-common-4ksx4iayav.pdf

Transancestral GWAS of alcohol dependence reveals common genetic underpinnings with psychiatric disorders

Epithelial to mesenchymal transition (EMT) is a process during which cells lose their epithelial characteristics, for instance cell polarity and cell-cell contact, and gain mesenchymal properties, such as increased motility. In colorectal cancer (CRC), EMT is associated with an invasive or metastatic phenotype. In this review, we discuss recent studies exploring novel regulation mechanisms of EMT in CRC, including the identification of new CRC EMT regulators. Upregulation of inducers can promote EMT, leading to increased invasiveness and metastasis in CRC. These inducers can downregulate E-cadherin and upregulate N-cadherin and vimentin (VIM) through modulating EMT-related signaling pathways, for instance WNT/β-catenin and TGF-β, and EMT transcription factors, such as zinc finger E-box binding homeobox 1 (ZEB1) and ZEB2. In addition, several microRNAs (miRNAs), including members of the miR-34 and miR-200 families, are found to target mRNAs of EMT-transcription factors, for example ZEB1, ZEB2, or SNAIL. Downregulation of these miRNAs is associated with distant metastasis and advanced stage tumors. Furthermore, the role of EMT in circulating tumor cells (CTCs) is also discussed. Mesenchymal markers on the surface of EMT CTCs were found to be associated with metastasis and could serve as potential biomarkers for metastasis. Altogether, these studies indicate that EMT is orchestrated by a complicated network, involving regulators of different signaling pathways. Further studies are required to understand the mechanisms underlying EMT in CRC.

https://www.mdpi.com/2072-6694/9/12/171/pdf

Regulation of EMT in Colorectal Cancer: A Culprit in Metastasis.

Alternative splicing is regulated by multiple RNA-binding proteins and influences the expression of most eukaryotic genes. However, the role of this process in human disease, and particularly in cancer, is only starting to be unveiled. We systematically analyzed mutation, copy number, and gene expression patterns of 1348 RNA-binding protein (RBP) genes in 11 solid tumor types, together with alternative splicing changes in these tumors and the enrichment of binding motifs in the alternatively spliced sequences. Our comprehensive study reveals widespread alterations in the expression of RBP genes, as well as novel mutations and copy number variations in association with multiple alternative splicing changes in cancer drivers and oncogenic pathways. Remarkably, the altered splicing patterns in several tumor types recapitulate those of undifferentiated cells. These patterns are predicted to be mainly controlled by MBNL1 and involve multiple cancer drivers, including the mitotic gene NUMA1 We show that NUMA1 alternative splicing induces enhanced cell proliferation and centrosome amplification in nontumorigenic mammary epithelial cells. Our study uncovers novel splicing networks that potentially contribute to cancer development and progression.

Large-scale analysis of genome and transcriptome alterations in multiple tumors unveils novel cancer-relevant splicing networks

MicroRNAs play an important role in the regulation of cancer migration, invasion and metastasis. Patients with triple-negative breast cancer (TNBC) have a high incidence of early relapse and metastasis; however, the molecular basis for metastasis and recurrence in these individuals remains largely unknown. Herein, we demonstrate that miR-136 is an anti-invasive microRNA in TNBC and suppresses mesenchymal invasion and metastasis. Our results demonstrated that miR-136 was downregulated in TNBC and negative correlated with the WHO grades. However, RASAL2 was identified as a functional target of miR-136, and was overexpressed in TNBC and correlates with pathological grades. Moreover, overexpression of RASAL2 in a breast cancer cell line rescued miR-136-mediated cell migration and invasion. In conclusion, these results indicate that the miR-136/RASAL2/MET axis act as a suppressor of TNBC metastasis.

/pdf/mir-136-suppresses-tumor-invasion-and-metastasis-by-43uxy5og8w.pdf

miR-136 suppresses tumor invasion and metastasis by targeting RASAL2 in triple-negative breast cancer.

Background: Runt-related transcription factor 3 (RUNX3) is a novel tumor suppressor gene that is frequently silenced by promoter hypermethylation in gastric cancer. In this study, we aimed to analyze the methylation status of the RUNX3 promoter in breast cancer and to evaluate the relationship between RUNX3 expression and breast carcinogenesis and prognosis. Methods: RT-PCR and Western blot were applied on 5 breast cancer cell lines, the human normal breast cell line Hs578Bst and 30 pairs of breast cancer and their matching normal breast tissues to detect mRNA and protein expression of the RUNX3 gene. Methylation-specific PCR was employed to detect the methylation status of the RUNX3 promoter. Immunohistochemical study was performed to analyze RUNX3 protein expression in 88 breast cancer tissues and 40 breast fibroadenomas. Results: The expression of RUNX3 mRNA and protein were negative in 3 breast cancer cell lines (T47D, MCF7 and SKBR3) as analyzed by RT-PCR and Western blotting. Hypermethylation of the RUNX3 promotor was identified in the T47D and MCF7 cell lines, but was not detected in SKBR3. Western blot analysis showed that the RUNX3 protein of 44 kDa was detected in 15 of 30 (50%) breast cancers. However, RUNX3 protein was detected in all normal breast tissues. Methylation was detected in 13 of the 15 tissues (86.67%) that did not express RUNX3 protein, but was never detected in any surrounding normal tissues. Immunohistochemistry results revealed that the positive rate of RUNX3 protein expression in breast cancer (35.23%) was much lower than that in breast fibroadenoma (85%). RUNX3 expression was correlated with tumor infiltration, clinical stage, lymph node metastasis and the expression of estrogen and progesterone receptor (p 0.05). The survival rate of the patients with RUNX3-positive expression was higher than that with RUNX3-negative expression (p Conclusions: The expression of RUNX3 gene is decreased in breast cancer. The RUNX3 gene may play an important role in the carcinogenesis of breast cancer. The mechanism of its inactivation may be hypermethylation of the promoter. With the increased progression of breast cancer, the expression of RUNX3 protein tends to decrease. The expression of RUNX3 protein has a definite value in judging prognosis in breast cancer.

/pdf/expression-of-runx3-gene-methylation-status-and-3knoqata4o.pdf

Expression of RUNX3 gene, methylation status and clinicopathological significance in breast cancer and breast cancer cell lines.

ING4, a new member of the ING (inhibitor of growth) family of tumour suppressor genes, has been found to be deleted or down-regulated in gliomas, breast tumours, and head and neck squamous cell carcinomas. The goal of the present study was to investigate whether the expression and alternative splicing of ING4 transcripts are involved in the initiation and progression of stomach adenocarcinoma. ING4 mRNA and protein expression was examined in gastric adenocarcinoma tissues and human gastric adenocarcinoma cell lines by RT-PCR, real-time RT-PCR, tissue microarray immunohistochemistry, and western blot analysis. Alterations in ING4 transcripts were determined through sequence analysis of ING4 cDNA. Our data showed that ING4 mRNA and protein were dramatically reduced in stomach adenocarcinoma cell lines and tissues, and significantly less in female than in male patients. We also found that reduced ING4 mRNA expression correlated with the stage of the tumour. Interestingly, by sequence analysis, we discovered five novel aberrantly spliced variant forms of ING4_v1 and ING4_v2. These variants cause a codon frame-shift and, eventually, deletion of the NLS or PHD domain contributing to the mislocalization of p53 and/or HAT/HDAC complexes and, subsequently, altered gene expression in gastric adenocarcinoma. These results suggest that attenuated and aberrant ING4 expression may be involved in the initiation and progression of stomach adenocarcinoma.

/pdf/reduced-expression-and-novel-splice-variants-of-ing4-in-2dkha58mp3.pdf

Reduced expression and novel splice variants of ING4 in human gastric adenocarcinoma

Wang Q-s, Li M, Zhang L-y, Jin Y, Tong D-d, Yu Y, Bai J, Huang Q, Liu F-L, Liu A, Lee K-Y & Fu S-b (2010) Histopathology 57, 271–281 Down-regulation of ING4 is associated with initiation and progression of lung cancer



Aims:  Tumour suppressor ING4 is one of ING family genes, which are involved in cell cycle arrest, gene transcription regulation, DNA repair and apoptosis. ING4 inhibition has been reported in various tumours, including gliomas, breast tumours, and stomach adenocarcinoma. The aim was to evaluate ING4 expression in lung cancers.



Method and results:  By immunohistochemistry of 246 lung tumour tissues, reduced ING4 nuclear and cytoplasmic expression were both revealed in lung cancer and associated with tumour grade. Interestingly, compared with normal tissues, we found more tumours with ING4 expression in the cytoplasm higher than in the nucleus. Nuclear ING4 inhibition correlated with the tumour stage and lymph node metastasis. Consistent with these findings, semiquantitative reverse transcriptase-polymerase chain reaction and Western blotting demonstrated decreased ING4 mRNA and expression in 100% (50/50) tumour tissues. Furthermore, ING4 expression was lower in grade III than in grades I–II tumours. Reduced ING4 mRNA correlated with lymph node metastasis.



Conclusions:  Our results indicate that overall inhibition of ING4 expression and ING4 expression higher in cytoplasm than in nucleus of tumour cells may be involved in the initiation and progression of lung cancers, and thus, analysis for ING4 expression may be useful as a clinical diagnostic and prognostic tool for lung cancer.

/pdf/down-regulation-of-ing4-is-associated-with-initiation-and-3ub361vurd.pdf

Down-regulation of ING4 is associated with initiation and progression of lung cancer.

Lung cancer is a leading cause of cancer-related death, about 40% human non-small cell lung cancer (NSCLC) patients showed lymph node involvements. However, the precise mechanism for the metastasis is still not fully understood. This study was to analyze the potential molecular mechanism for lung cancer metastasis. In the current study, proteomics analysis by two-dimensional electrophoresis (2-DE) was performed first to identify the differentially expressed protein between the higher metastasis lung adenocarcinoma cell line Anip973 and the lower metastasis lung adenocarcinoma cell line AGZY83-a. We confirmed the result by RT-PCR, immunoblotting and immunocytochemistry analyses in these two cell lines. Then we examined the expression of the differentially expressed protein in tumor tissues of NSCLC patients by immunoblotting and immunohistochemistry analyses. Using 2-DE analysis, we have identified DJ-1 was expressed higher in the higher metastasis Anip973 compared to the parental cell line AGZY83-a, that was confirmed by RT-PCR, immunoblotting and immunocytochemistry analyses. In NSCLC patients' tumor tissues study, immunoblotting data showed that, DJ-1 expression level was significantly higher in 72.2% (13/18) of NSCLC tissue samples compared to that in paired normal lung tissues (P = 0.044). Immunohistochemistry analysis demonstrated increased DJ-1 expression in 85 NSCLC tumor tissue samples compared with 7 normal lung tissue samples (P = 0.044). DJ-1 expression was also found to be significantly correlated with cancer lymphatic metastasis (P = 0.039). DJ-1 might contribute to the metastasis of NSCLC.

Dandan Tong

Papers

miR-136 suppresses tumor invasion and metastasis by targeting RASAL2 in triple-negative breast cancer.

Expression of RUNX3 gene, methylation status and clinicopathological significance in breast cancer and breast cancer cell lines.

Reduced expression and novel splice variants of ING4 in human gastric adenocarcinoma

Down-regulation of ING4 is associated with initiation and progression of lung cancer.

DJ-1 may contribute to metastasis of non-small cell lung cancer.