Genetic alterations in LEP and ADIPOQ genes and risk for breast cancer: a meta-analysis.

Introduction: Breast cancer has a strong genetic predisposition, and its genetic architecture is not fully understood thus far. In this study, we aimed to perform a meta-analysis to evaluate the association of genetic alterations in LEP and ADIPOQ genes, as well as their receptor-encoded genes with risk for breast cancer. Methods: Only published studies conducted in humans and written in English were identified by searching PubMed, SCOPUS, CINAHIL and Embase from their inception to October 2022. Eligibility assessment and data collection were completed independently by two researchers. Statistical analyses were done using the STATA software. Results: After literature search, 33 publications were eligible for inclusion. Overall, LEP gene rs7799039-G allele (odds ratio [OR]: 0.78, 95% confidence interval [CI]: 0.62 to 0.98) and ADIPOQ gene rs1501299-T allele (OR: 1.41, 95% CI: 1.06 to 1.88) were associated with the significant risk of breast cancer. In subgroup analyses, differences in menopausal status, obesity, race, study design, diagnosis of breast cancer, genotyping method and sample size might account for the divergent observations of individual studies. Circulating leptin levels were comparable across genotypes of LEP gene rs7799039, as well as that of LEPR gene rs1137101 (P>0.05). Begg's funnel plots seemed symmetrical, with the exception of LEPR gene rs1137100 and ADIPOQ gene rs1501299. Discussion: Taken together, we found, in this meta-analysis, that LEP gene rs7799039 and ADIPOQ gene rs1501299 were two promising candidate loci in predisposition to breast cancer risk.

hnRNPA2B1 regulates the alternative splicing of BIRC5 to promote gastric cancer progression.

BACKGROUND: Systematic profiling studies have implicated regulators of pre-mRNA splicing as important disease determinants in gastric cancer (GC), but the underlying mechanisms have remained elusive. Here we focused on hnRNPA2B1 splicing factor-dependent mechanisms governing GC development. METHODS: The expression of hnRNPA2B1 was analyzed among the Cancer Genome Atlas (TCGA) datasets of GC and validated at mRNA level. The function of hnRNPA2B1 in GC cells was analyzed and its downstream gene was identified using RNA immunoprecipitation. Further, effect of hnRNPA2B1 on BIRC5 alternative splicing was investigated. RESULTS: We show that overexpression of hnRNPA2B1 in GC is correlated with poor survival, and hnRNPA2B1 is required for maintaining GC malignant phenotype by promoting cell proliferation, inhibiting cell apoptosis and increasing cell metastasis. Mechanistically, hnRNPA2B1 co-expressed with several core spliceosome components and controls alternative splicing of anti-apoptotic factor BIRC5. BIRC5 isoform 202 (BIRC5-202) played the oncogenic function in GC cells, and overexpression of the BIRC5-202 transcript partly rescued the decrease in cisplatin resistance induced by downregulation of hnRNPA2B1. CONCLUSIONS: We demonstrate that hnRNPA2B1 regulates BIRC5 splicing and might act as a therapeutic target of chemo-resistant GC cells.

Effects of different culture systems on the culture of prepuberal buffalo (Bubalus bubalis) spermatogonial stem cell-like cells in vitro

Currently, the systems for culturing buffalo spermatogonial stem cells (SSCs) in vitro are varied, and their effects are still inconclusive. In this study, we compared the effects of culture systems with undefined (foetal bovine serum) and defined (KnockOut Serum Replacement) materials on the in vitro culture of buffalo SSC-like cells. Significantly more DDX4- and UCHL1-positive cells (cultured for 2 days at passage 2) were observed in the defined materials culture system than in the undefined materials system (p < 0.01), and these cells were maintained for a longer period than those in the culture system with undefined materials (10 days vs. 6 days). Furthermore, NANOS2 (p < 0.05), DDX4 (p < 0.01) and UCHL1 (p < 0.05) were expressed at significantly higher levels in the culture system with defined materials than in that with undefined materials. Induction with retinoic acid was used to verify that the cultured cells maintained SSC characteristics, revealing an SCP3⁺ subset in the cells cultured in the defined materials system. The expression levels of Stra8 (p < 0.05) and Rec8 (p < 0.01) were significantly increased, and the expression levels of ZBTB16 (p < 0.01) and DDX4 (p < 0.05) were significantly decreased. These findings provided a clearer research platform for exploring the mechanism of buffalo SSCs in vitro.

Effects of different culture systems on the culture of prepuberal buffalo (Bubalus bubalis) spermatogonial stem cell-like cells in vitro

Currently, the systems for culturing buffalo spermatogonial stem cells (SSCs) in vitro are varied, and their effects are still inconclusive. In this study, we compared the effects of culture systems with undefined (foetal bovine serum) and defined (KnockOut Serum Replacement) materials on the in vitro culture of buffalo SSC-like cells. Significantly more DDX4- and UCHL1-positive cells (cultured for 2 days at passage 2) were observed in the defined materials culture system than in the undefined materials system (p < 0.01), and these cells were maintained for a longer period than those in the culture system with undefined materials (10 days vs. 6 days). Furthermore, NANOS2 (p < 0.05), DDX4 (p < 0.01) and UCHL1 (p < 0.05) were expressed at significantly higher levels in the culture system with defined materials than in that with undefined materials. Induction with retinoic acid was used to verify that the cultured cells maintained SSC characteristics, revealing an SCP3⁺ subset in the cells cultured in the defined materials system. The expression levels of Stra8 (p < 0.05) and Rec8 (p < 0.01) were significantly increased, and the expression levels of ZBTB16 (p < 0.01) and DDX4 (p < 0.05) were significantly decreased. These findings provided a clearer research platform for exploring the mechanism of buffalo SSCs in vitro.

Effects of different culture systems on the culture of prepuberal buffalo (Bubalus bubalis) spermatogonial stem cell-like cells in vitro

hnRNPK promotes gastric tumorigenesis through regulating CD44E alternative splicing.

BACKGROUND: The high prevalence of alternative splicing among genes implies the importance of genomic complexity in regulating normal physiological processes and diseases such as gastric cancer (GC). The standard form of stem cell marker CD44 (CD44S) and its alternatives with additional exons are reported to play important roles in multiple types of tumors, but the regulation mechanism of CD44 alternative splicing is not fully understood. METHODS: Here the expression of hnRNPK was analyzed among the Cancer Genome Atlas (TCGA) cohort of GC. The function of hnRNPK in GC cells was analyzed and its downstream targeted gene was identified by chromatin immunoprecipitation and dual luciferase report assay. Finally, effect of hnRNPK and its downstream splicing regulator on CD44 alternative splicing was investigated. RESULTS: The expression of hnRNPK was significantly increased in GC and its upregulation was associated with tumor stage and metastasis. Loss-of-function studies found that hnRNPK could promote GC cell proliferation, migration, and invasion. The upregulation of hnRNPK activates the expression of the splicing regulator SRSF1 by binding to the first motif upstream the start codon (- 65 to - 77 site), thereby increasing splicing activity and expression of an oncogenic CD44 isoform, CD44E (has additional variant exons 8 to 10, CD44v8-v10). CONCLUSION: These findings revealed the importance of the hnRNPK-SRSF1-CD44E axis in promoting gastric tumorigenesis.

Effect of Cynomorium songaricum polysaccharide on telomere of lung cancer A549 cells / 中国中药杂志

To study the effect of Cynomorium songaricum polysaccharide (CSRP) on A549 cells telomere of human non-small cell lung cancer, the mice were intragastric administrated with CSRP (0.08 g•kg⁻¹) once daily for 4 days. Then their serum was taken for preparing CSRP drug serum. A549 cells were treated by the drug serum, and the effect of drug serum with different concentrations and different treating time on the proliferation of non-small cell lung cancer A549 cells was determined by MTT test. After treating for 48 hours by the drug serum of different concentrations, the telomere length of the cells was determined by fluorescence quantitative polymerase chain reaction (qPCR); the mRNA expression of telomerase reverse transcriptase (TERT) was determined by RT-qPCR; the cells apoptosis was determined by TUNEL assay. The results demonstrated that CSRP of various concentrations could inhibit the proliferation of the lung cancer A549 cells significantly, and the inhibition effect was strongest at 48 hours with the concentration of 6.0 mL•L⁻¹. At 48 h, that CSRP of the concentrations from 1.5 to 12.0 mL•L⁻¹ could significantly shorten the telomere length of A549 cells, and the effect was strongest with the concentration of 1.5 mg•L⁻¹. CSRP of various concentrations could significantly inhibit the mRNA expression of TERT in A549 cells, and the inhibition effect was stronger when the concentration was ≥6.0 mL•L⁻¹. CSRP of various concentrations could promote A549 cells apoptosis, and the effect was stronger when the concentration was ≥6.0 mL•L⁻¹. In conclusion, CSRP has the anti-cancer effect, and the action mechanism may be associated with inhibiting TERT mRNA expression, shortening telomere length, inhibiting cells proliferation and promoting cells apoptosis.

Role of miR-191/425 cluster in tumorigenesis and diagnosis of gastric cancer.

Gastric cancer (GC) is among the most frequent types of cancer worldwide. Therefore, understanding the biology of GC tumorigenesis is important for appropriate diagnosis and patient surveillance. The miR-191/425 cluster has been reported to be overexpressed in various human cancers, but the tumorigenic role and clinical significance of miR-191/425 overexpression in gastric carcinogenesis is currently undefined. In this study, the expression of miR-191 and miR-425 in GC tissue and serum was assessed, and the relationship between miRNA expression and clinicopathological data was analyzed. We found that miR-191 and miR-425 were both significantly increased in human GC tissues relative to adjacent normal controls. In addition, miR-191 levels correlated with GC tumor stage and metastatic state. Furthermore, the level of serum miR-191 was significantly higher in the GC group than in the control group when using serum miR-16 as an endogenous control. Finally, inhibition of miR-191 or miR-425 in the GC cell lines HGC-27 not only reduced cell proliferation and cell cycle progression but also impaired cell migration and invasion. Taken together, our results revealed the oncogenic roles of miR-191 and miR-425 in gastric carcinogenesis, and indicated the potential use of serum miR-191 as a novel and stable biomarker for GC diagnosis.

[Effect of combination of eicosapentaenoic acid and epirubicin on human gastric carcinoma cell strain MGC-803].

OBJECTIVE: To evaluate the effect of combination of eicosapentaenoic acid (EPA) and The effects of EPA and epirubicin (EPI) on the human gastric carcinoma cell MGC-803 in vitro. METHODS: EPI were measured by MTT assay , and the interaction between these two agents was evaluated by the isobologram technique of Berenbaum. Morphous of cell was observed by phase-contrast and electron microscope. Flow cytometry was used for cell cycle analysis. RESULTS: EPA significantly inhibited the growth of MGC-803 cells in a dose- and time-dependent way (P < 0.01). Numerous abnormal particles were found around the nucleus of MGC-803 cells under phase-contrast microscope, and also many electron-dense material in cytoplasm were found under electron microscope. EPA significantly stimulated the growth of human embryonal pulmonary fibroblast (HPF) dose-dependently (P < 0.01). A strong synergism was found between EPA and EPI in MGC-803 cells. EPA induced G0/G1-phase arrest but without statistical significance (P > 0.05), and EPI significantly induced S-phase arrest (P < 0.05) in MGC-803 cells. CONCLUSIONS: EPA can inhibit cell growth in gastric carcinoma cells but not in normal cells. EPA and EPI have synergetic effect in the inhibition of gastric carcinoma cells. Compared with EPI monotherapy, the combination of EPI and EPA can reduce the dosage of EPI.

[Effect of combination of glutamine and mitomycin C on human gastric carcinoma cell strain MGC-803].

OBJECTIVE: To evaluate the effect of combination of glutamine (GLN) and mitomycin C (MMC) on the human gastric carcinoma cell line MGC-803 in vitro. METHODS: The effects of GLN and MMC were measured by MTT assay, and the interaction between the two agents was evaluated by the median-effect principle. Flow cytometry was used for cell cycle analysis. RESULTS: GLN did not significantly stimulate the cell growth in vitro. High-concentration of GLN could inhibit the cell growth. MMC could effectively inhibit the cell growth in a time-dependent manner. The interaction of these two agents showed a weak antagonistic activity (1 < CI < 1.2703). MMC induced remarkable S-phase arrest. Low-dose GLN has limited effect on the S-phase arrest of MMC, while high-dose GLN significantly attenuated the S-phase arrest and lowered the proliferation index of MGC-803 cell. CONCLUSIONS: Combination of GLN and MMC has a a weak and dose-dependent antagonistic activity in the treatment of gastric carcinoma cell line MGC-803. The combination of high-dose MMC and low-dose GLN may achieve better efficacy.