Breast cancer development and progression:Risk factors,cancer stem cells,signaling pathways,genomics,and molecular pathogenesis

As the most commonly occurring cancer in women worldwide,breast cancer poses a formidable public health challenge on a global scale.Breast cancer consists of a group of biologically and molecularly heterogeneous diseases originated from the breast.While the risk factors associated with this cancer varies with respect to other cancers,genetic predisposition,most notably mutations in BRCA1 or BRCA2 gene,is an important causative factor for this malignancy.Breast cancers can begin in different areas of the breast,such as the ducts,the lobules,or the tissue in between.Within the large group of diverse breast carcinomas,there are various denoted types of breast cancer based on their invasiveness relative to the primary tumor sites.It is important to distinguish between the various subtypes because they have different prognoses and treatment implications.As there are remarkable parallels between normal development and breast cancer progression at the molecular level,it has been postulated that breast cancer may be derived from mammary cancer stem cells.Normal breast development and mammary stem cells are regulated by several signaling pathways,such as estrogen receptors(ERs),HER2,and Wnt/b-catenin signaling pathways,which control stem cell proliferation,cell death,cell differentiation,and cell motility.Furthermore,emerging evidence indicates that epigenetic regulations and noncoding RNAs may play important roles in breast cancer development and may contribute to the heterogeneity and metastatic aspects of breast cancer,especially for triple-negative breast cancer.This review provides a comprehensive survey of the molecular,cellular and genetic aspects of breast cancer.

Depression and stress levels increase risk of liver cancer through epigenetic downregulation of hypocretin

Recent studies suggest that Hypocretin (HCRT, Orexin) are involved in stress regulation of depression through the hypothalamic-pituitary-adrenal (HPA) axis. However, the molecular mechanism by which Hypocretin regulate neurobiological responses is unknown. Herein, the effects of chronic stress on the epigenetic modification of HCRT and its association with depression were explored with regard to a potential role in cancer progression. In the study, Sprague Dawley (SD) rats were used to establish an animal model of cancer with depression by administrating n-nitrosodiethylamine (DEN) and chronic unpredictable mild stress (CUMS). RNA-sequencing was used to detect differentially expressed genes in the hippocampus of rats and quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the results of RNA-sequencing. The status of HCRT promoter methylation was assessed by methylation specific polymerase chain reaction. Behavioral tests showed that rats exposed to CUMS had significant depressive-like behaviors. The number of liver tumors and tumor load in depressed rats exposed to CUMS was higher than in SD rats without CUMS. RNA-sequencing revealed that HCRT was one of the most siginificantly downregulated gene in the hippocampus of SD rats with CUMS compared to non-stressed group, which was validated by qRT-PCR. HCRT mRNA expression was downregulated and the promoter for HCRT was hyper-methylated in those with depression. These results identified a critical role for chronic psychological stressors in tumorigenesis and cancer progression, via epigenetic HCRT downregulation. Such epigenetic downregulation may be the molecular basis for the association of cancer with depression.

Breast cancer development and progression: Risk factors, cancer stem cells, signaling pathways, genomics, and molecular pathogenesis

As the most commonly occurring cancer in women worldwide,breast cancer poses a formidable public health challenge on a global scale.Breast cancer consists of a group of biologically and molecularly heterogeneous diseases originated from the breast.While the risk factors associated with this cancer varies with respect to other cancers,genetic predisposition,most notably mutations in BRCA1 or BRCA2 gene,is an important causative factor for this malignancy.Breast cancers can begin in different areas of the breast,such as the ducts,the lobules,or the tissue in between.Within the large group of diverse breast carcinomas,there are various denoted types of breast cancer based on their invasiveness relative to the primary tumor sites.It is important to distinguish between the various subtypes because they have different prognoses and treatment implications.As there are remarkable parallels between normal development and breast cancer progression at the molecular level,it has been postulated that breast cancer may be derived from mammary cancer stem cells.Normal breast development and mammary stem cells are regulated by several signaling pathways,such as estrogen receptors(ERs),HER2,and Wnt/b-catenin signaling pathways,which control stem cell proliferation,cell death,cell differentiation,and cell motility.Furthermore,emerging evidence indicates that epigenetic regulations and noncoding RNAs may play important roles in breast cancer development and may contribute to the heterogeneity and metastatic aspects of breast cancer,especially for triple-negative breast cancer.This review provides a comprehensive survey of the molecular,cellular and genetic aspects of breast cancer.

Zinc-finger protein 382 antagonises CDC25A and ZEB1 signaling pathway in breast cancer

Our previous studies found that Zinc-finger protein 382(ZNF382)played as a tumor suppressor gene in esophageal and gastric cancers,and a positive correlation between the high expression of ZNF382 and better outcome in breast cancer patients.However,the biological roles and mechanisms of ZNF382 in breast cancer remains unclear.We detected ZNF382 expression by reverse-transcription PCR(RT-PCR)and real-time quantitative PCR(qRT-PCR)in breast cancer cells and tissues,and explored the impacts and mechanisms of ectopic ZNF382 expression in breast cancer cells in vitro and in vivo,respectively.Our results revealed that ZNF382 was significantly down-regulated in breast cancer tissues compared with adjacent non-cancer tissues.Restoration of ZNF382 expression in silenced breast cancer cells not only inhibited tumor cell colony formation,viability,migration and invasion,and epithelial-mesenchymal-transition(EMT),but also induced apoptosis and G0/G1 arrest.In conclusion,ZNF382 could induce G0/G1 cell cycle arrest through inhibiting CDC25A signaling,and,inhibit cell migration,invasion and EMT by antagonizing ZEB1 signaling in breast cancer cells.

LPCAT1 functions as a novel prognostic molecular marker in hepatocellular carcinoma

This study aimed to investigate the relationships between LPCAT1 expression and clinicopathologic parameters of hepatocellular carcinoma(HCC),further,to explore the effect of LPCAT1 on overall survival(OS)in patients with HCC,and its possible mechanism.Bioinformatics analysis using high throughput RNA-sequencing data from TCGA was utilized to explore the differential expression of LPCAT1 between normal and tumor tissues,and the associations between LPCAT1 expression and clinicopathological parameters.Survival analyses and subgroup survival analyses were utilized to elucidate the effect of LPCAT1 on OS in patients with HCC.Univariate analysis and multivariate analysis were used to investigate the prognostic factors.Potential LPCAT1 related tumor genes were identified by the methodology of differentially expressed genes(DEGs)screening.GO term enrichment analysis,KEGG pathway analysis and the PPI network were used to explore the potential mechanism.LPCAT1 was significantly overexpressed in HCC tumor tissues compared with normal tissues.The LPCAT1 expression was related to tumor grade,ECOG score,AFP and TNM stage,with P values of 0.000,0.000,0.007 and 0.000,respectively.Multivariate analysis demonstrated that LPCAT1 expression was independently associated with OS,with an HR of 1.04(CI:1.01–1.06,P=0.003).The KEGG pathway enrichment analyses showed that overlapped DEGs mainly participate in the cell cycle.Finally,we identified a hub gene,CDK1,which has been reported to act on the cell cycle,consistent with the result of KEGG enrichment analysis.Collectively,these data confirmed LPCAT1 was upregulated in HCC,and was an independent predictor of the prognosis.