RSRC1 and CPZ gene polymorphisms with neuroblastoma susceptibility in Chinese children

Hic-5 regulates extracellular matrix-associated gene expression and cytokine secretion in cancer associated fibroblasts

The focal adhesion protein, Hic-5 plays a key role in promoting extracellular matrix deposition and remodeling by cancer associated fibroblasts within the tumor stroma to promote breast tumor cell invasion. However, whether stromal matrix gene expression is regulated by Hic-5 is still unknown. Utilizing a constitutive Hic-5 knockout, Mouse Mammary Tumor Virus-Polyoma Middle T-Antigen spontaneous breast tumor mouse model, bulk RNAseq analysis was performed on cancer associated fibroblasts isolated from Hic-5 knockout mammary tumors. Functional network analysis highlighted a key role for Hic-5 in extracellular matrix organization, with both structural matrix genes, as well as matrix remodeling genes being differentially expressed in relation to Hic-5 expression. The subcellular distribution of the MRTF-A transcription factor and expression of a subset of MRTF-A responsive genes was also impacted by Hic-5 expression. Additionally, cytokine array analysis of conditioned media from the Hic-5 and Hic-5 knockout cancer associated fibroblasts revealed that Hic-5 is important for the secretion of several key factors that are associated with matrix remodeling, angiogenesis and immune evasion. Together, these data provide further evidence of a central role for Hic-5 expression in cancer associated fibroblasts in regulating the composition and organization of the tumor stroma microenvironment to promote breast tumor progression.

Effect of Competitive Adsorption of MicroRNA-1297 Between Metastasis-Associated Lung Adenocarcinoma Transcript 1 and E2F Transcription Factor 7 on the Proliferation of the Neuroblastoma Cell Line LA-N-5 Human Neuroblastoma Cell

Objective: To investigate: (1) the role of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in neuroblastoma cell proliferation and; (2) molecular mechanisms underlying the effect. Methods: The cell lines SH-SY5Y, SK-N-SH, and LA-N-5 (neuroblastomas) and the cell line HEK-293 (embryonic kidney) were cultured in vitro. We performed reverse transcription polymerase chain reaction to verify relative gene expressions; WST-8 assay to determine cell proliferation; colony formation assay to analyze cell clonogenic capacity; and western blotting to assess relative protein expressions. Dual-fluorescent reporters were constructed to verify gene–gene interactions. Results: MALAT1 expression was highest in LA-N-5. Decreased MALAT1 expression in LA-N-5 cells effectively inhibited proliferation, increased microRNA (miR)-1297 expression, and decreased E2F transcription factor 7 (E2F7) expression. MALAT1 bound to miR-1297, which then bound to E2F7–both in a targeted manner. Conclusion: MALAT1 acts as an miR-1297 sponge, abolishing the inhibitory actions of miR-1297 on E2F7 translation and ultimately affecting neuroblastoma cell proliferation. Our findings are consistent with the potential of targeting MALAT1 in neuroblastoma treatment.

Genetic predisposition and chromosome instability in neuroblastoma

Neuroblastoma (NB) is a pediatric tumor of embryonic origin. About 1-2% of all NBs are familial cases, and genetic predisposition is suspected for the remaining cases. During the last decade, genome-wide association studies (GWAS) and high-throughput sequencing approaches have been used to identify associations among common and rare genetic variants and NB risk. Substantial data has been produced by large patient cohorts that implicate various genes in NB tumorigenesis, such as CASC15, BARD1, CHEK2, LMO1, LIN28B, AXIN2, BRCA1, TP53, SMARCA4, and CDK1NB. NB, as well as other pediatric cancers, has few recurrent mutations but several copy number variations (CNVs). Almost all NBs show both numerical and structural CNVs. The proportion between numerical and structural CNVs differs between localized and metastatic tumors, with a greater prevalence of structural CNVs in metastatic NB. This genomic chaos frequently identified in NBs suggests that chromosome instability (CIN) could be one of the major actors in NB oncogenesis. Interestingly, many NB-predisposing variants occur in genes involved in the control of genome stability, mitosis, and normal chromosome separation. Here, we discuss the relationship between genetic predisposition and CIN in NB.

RSRC1 suppresses gastric cancer cell proliferation and migration by regulating PTEN expression

Arginine/serine-rich coiled coil 1 (RSRC1) is a gene which plays a significant role in the constitutive and alternative splicing of mRNA and transcriptional regulation. It has been implicated in various neurological disorders, as well as in cancer. However, its role in gastric cancer (GC) remains unknown. Thus, the present study aimed to investigate the role of RSRC1 in GC. RSRC1 expression in GC tissues was determined by RT-qPCR and immunohistochemical staining. The effects of RSRC1 on cell proliferation and migration were detected using a Cell Counting Kit-8 assay, 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay and a Transwell migration assay. Western blot analysis and RT-qPCR were used to explore the molecular mechanisms of of action of RSRC1 in GC. The results indicated that RSRC1 expression was downregulated in GC tissues compared to paired normal tissues and the reduced expression of RSRC1 was shown to contribute to a poor prognosis of patients with GC. RSRC1 knockdown promoted the proliferation and migration of GC cells. In addition, the knockdown of RSRC1 decreased the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a potent tumor suppressor gene controlling cellular growth and viability. On the whole, the findings of the present study indicate that RSRC1 functions as a tumor suppressor gene in GC and that it may exert its effects by regulating PTEN expression.

APEX1 Polymorphisms and Neuroblastoma Risk in Chinese Children: A Three-Center Case-Control Study

Neuroblastoma is a life-threatening extracranial solid tumor, preferentially occurring in children. However, its etiology remains unclear. APEX1 is a critical gene in the base excision repair (BER) system responsible for maintaining genome stability. Given the potential effects of APEX1 polymorphisms on the ability of the DNA damage repair, many studies have investigated the association between these variants and susceptibility to several types of cancer but not neuroblastoma. Here, we conducted a three-center case-control study to evaluate the association between APEX1 polymorphisms (rs1130409 T>G, rs1760944 T>G, and rs3136817 T>C) and neuroblastoma risk in Chinese children, consisting of 469 cases and 998 controls. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated to evaluate the associations. No significant association with neuroblastoma risk was found for the studied APEX1 polymorphisms in the single locus or combination analysis. Interestingly, stratified analysis showed that rs1130409 GG genotype significantly reduced the risk of tumor in males. Furthermore, we found that carriers with 1-3 protective genotypes had a lower neuroblastoma risk in the children older than18 months and male, when compared to those without protective genotypes. In summary, our data indicate that APEX1 gene polymorphisms may have a weak effect on neuroblastoma susceptibility. These findings should be further validated by well-designed studies with larger sample size.