BTF3 Silencing Inhibits the Proliferation of Osteosarcoma Cells

BTF3 promotes proliferation and glycolysis in hepatocellular carcinoma by regulating GLUT1

Hepatocellular carcinoma (HCC) is a grievous tumor with an increasing incidence worldwide. Basic transcription factor 3 (BTF3) is discovered to regulate the expression of glucose transporter 1 (GLUT1), which benefits glycolysis, a momentous signature of tumors, through transactivation of the forkhead box M1 (FOXM1) expression. BTF3 is highly expressed in HCC. However, whether BTF3 promotes GLUT1 expression through FOXM1 to modulate glycolysis in HCC remains unclear. The expression profile of BTF3 were determined by online database, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot. The role and mechanism of BTF3 in the proliferation and glycolysis of HCC cells were examined by cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) incorporation, XF96 Extracellular Flux analyzer, spectrophotometry and western blot analysis. In addition, the direct interaction between BTF3 and FOXM1 was verified by dual-luciferase reporter and co-immunoprecipitation assays. Moreover, the role of BTF3 was also explored in a xenografted mice model. The expression of BTF3 was increased in HCC cells and tumor tissues. Knockdown of BTF3 reduced the cell viability, Edu positive cells, extracellular acidification rate (ECAR), glucose consumption and lactate production in both Huh7 and HCCLM3 cells. The expressions of FOXM1 and GLUT1 were increased in HCC tissues, which were positively correlated with the BTF3 expression. Moreover, a direct interaction existed between BTF3 and FOXM1 in HCC cells. Downregulation of BTF3 decreased the relative protein levels of FOXM1 and GLUT1, which were rescued with overexpression of FOXM1 in both cells. More importantly, overexpression of FOXM1 restored the cell viability, ECAR, glucose consumption and lactate production in both Huh7 and HCCLM3 cells transfected with siBTF3#1. Furthermore, inhibition of BTF3 decreased tumor weight and volume, and the relative level of BTF3, FOXM1, GLUT1 and Ki-67 in tumor tissues from mice xenografted with Huh7 cells. BTF3 enhanced the cell proliferation and glycolysis through FOXM1/GLUT1 axis in HCC.

LncRNA-ZNF252P-AS1/miR-15b-5p promotes the proliferation of keloid fibroblast by regulating the BTF3-STAT3 signaling pathway

BACKGROUND

JAK2/STAT3 signaling pathway plays an important role in keloid formation, but the upstream mechanism of their activation remains unclear.

OBJECTIVE

This study aims to investigate the possible mechanism of lncRNA-ZNF252P-AS1 in keloid.

METHODS

The differentially expressed genes in keloid and their upstream regulatory miRNAs and long non-coding RNAs (lncRNAs) were analyzed by bioinformatics database, and the targeting relationship was further verified by dual-luciferase reporter gene assay. LncRNA function as competitive endogenous RNA (ceRNA) in keloid was further verified by in keloid fibroblasts (KFs) and in nude mice with subcutaneous keloids.

RESULTS

BTF3 expression was up-regulated in keloid tissues. The targeting relationship between BTF3 and miR-15b-5p was confirmed by dual-luciferase reporter gene assay. miR-15b-5p overexpression inhibited BTF3, Bcl-2, Cyclin D1, C-myc, Collagen I, MMP2, MMP9, N-cadherin, and ZEB2 expressions in KFs, inhibited cell proliferation and migration, while promoted E-cadherin levels. BTF3 overexpression reversed miR-15b-5p effects on KFs. Bioinformatics analysis as well as clinical and cellular experiments confirmed that the lncRNA ZNF252P-AS1 was highly expressed in keloid/KFs. Dual-luciferase reporter gene assays confirmed the targeting relationship between lncRNA ZNF252P-AS1 and miR-15b-5p. LncRNA ZNF252P-AS1 overexpression inhibited miR-15b-5p and E-cadherin levels, upregulated BTF3, Bcl-2, Cyclin D1, C-myc, Collagen I, MMP2, MMP9, N-cadherin, and ZEB2 expressions, increased cell proliferation and migration, and activated JAK2/STAT3 pathway, while miR-15b-5p overexpression reversed this effect. The in vivo results were consistent with in vitro results. In vivo experiments further confirmed that lncRNA ZNF252P-AS1 reduced keloid volume and weight.

CONCLUSION

lncRNA ZNF252P-AS1 is a potential target for keloid treatment.

MiR-27a-5p regulates acrylamide-induced mitochondrial dysfunction and intrinsic apoptosis via targeting Btf3 in rats

Acrylamide (AA), a potential carcinogen, is commonly formed in foods rich in carbohydrates at high heat. It is known that AA-induced mitochondrial dysfunction is responsible for its toxicity. Previously we found AA exposure increased miR-27a-5p expression in livers of SD rats. Here, the regulation mechanism of miR-27a-5p in mitochondrial dysfunction was investigated in rat liver cell lines (IAR20) and SD rats. The results showed that the overexpressed miR-27a-5p contributes to modulating mitochondrial dysfunction and Btf3 is identified as its target gene. The knockdown of Btf3 increases the cleaved PARP1 level and the phosphorylation of ATM and p53, which results in mitochondria-dependent apoptosis. Therefore, the miR-27a-5p-Btf3-ATM-p53 axis might play a vital role in the promotion of AA-induced cell apoptosis through disrupting mitochondrial structure and function. This would provide a potential target for the assessment and intervention of AA toxicity.

Ribosomal Protein S6: A Potential Therapeutic Target against Cancer?

Ribosomal protein S6 (RPS6) is a component of the 40S small ribosomal subunit and participates in the control of mRNA translation. Additionally, phospho (p)-RPS6 has been recognized as a surrogate marker for the activated PI3K/AKT/mTORC1 pathway, which occurs in many cancer types. However, downstream mechanisms regulated by RPS6 or p-RPS remains elusive, and the therapeutic implication of RPS6 is underappreciated despite an approximately half a century history of research on this protein. In addition, substantial evidence from RPS6 knockdown experiments suggests the potential role of RPS6 in maintaining cancer cell proliferation. This motivates us to investigate the current knowledge of RPS6 functions in cancer. In this review article, we reviewed the current information about the transcriptional regulation, upstream regulators, and extra-ribosomal roles of RPS6, with a focus on its involvement in cancer. We also discussed the therapeutic potential of RPS6 in cancer.

Molecular Chaperones in Osteosarcoma: Diagnosis and Therapeutic Issues

Osteosarcoma (OS) is the most common form of primary bone tumor affecting mainly children and young adults. Despite therapeutic progress, the 5-year survival rate is 70%, but it drops drastically to 30% for poor responders to therapies or for patients with metastases. Identifying new therapeutic targets is thus essential. Heat Shock Proteins (HSPs) are the main effectors of Heat Shock Response (HSR), the expression of which is induced by stressors. HSPs are a large family of proteins involved in the folding and maturation of other proteins in order to maintain proteostasis. HSP overexpression is observed in many cancers, including breast, prostate, colorectal, lung, and ovarian, as well as OS. In this article we reviewed the significant role played by HSPs in molecular mechanisms leading to OS development and progression. HSPs are directly involved in OS cell proliferation, apoptosis inhibition, migration, and drug resistance. We focused on HSP27, HSP60, HSP70 and HSP90 and summarized their potential clinical uses in OS as either biomarkers for diagnosis or therapeutic targets. Finally, based on different types of cancer, we consider the advantage of targeting heat shock factor 1 (HSF1), the major transcriptional regulator of HSPs in OS.

Molecular Characterization of the Oncogene BTF3 and Its Targets in Colorectal Cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed and leading causes of cancer mortality worldwide, and the prognosis of patients with CRC remains unsatisfactory. Basic transcription factor 3 (BTF3) is an oncogene and hazardous prognosticator in CRC. Although two distinct functional mechanisms of BTF3 in different cancer types have been reported, its role in CRC is still unclear. In this study, we aimed to molecularly characterize the oncogene BTF3 and its targets in CRC. Here, we first identified the transcriptional targets of BTF3 by applying combined RNA-Seq and ChIP-Seq analysis, identifying CHD1L as a transcriptional target of BTF3. Thereafter, we conducted immunoprecipitation (IP)-MS and E3 ubiquitin ligase analysis to identify potential interacting targets of BTF3 as a subunit of the nascent-polypeptide-associated complex (NAC). The analysis revealed that BTF3 might also inhibit E3 ubiquitin ligase HERC2-mediated p53 degradation. Finally, miRNAs targeting BTF3 were predicted and validated. Decreased miR-497-5p expression is responsible for higher levels of BTF3 post-transcriptionally. Collectively, we concluded that BTF3 is an oncogene, and there may exist a transcription factor and NAC-related proteolysis mechanism in CRC. This study provides a comprehensive basis for understanding the oncogenic mechanisms of BTF3 in CRC.

Expression Profile of Chicken Sex Chromosome Gene BTF3 is Linked to Gonadal Phenotype

In birds, the female is heterogametic (ZW) and the male homogametic (ZZ). The small W chromosome comprises only 28 protein coding genes (homologues to Z chromosome counterparts) and a number of repeat regions. Here, we report our analysis of one of these genes, BTF3 (basic transcription factor 3), which exhibits differential expression during gonadogenesis. We measured RNA levels of both Z and W homologues and BTF3 protein levels in male and female gonads during development of the chicken embryo. In addition, BTF3 RNA and protein levels were compared in female gonads (ovary) and in female gonads following treatment to induce sex reversal (testis). Combined BTF3 RNA levels were higher in female gonads than male gonads, while BTF3-Z was expressed at similar levels in males and females. Surprisingly, BTF3 protein levels were higher in male gonads than female gonads at embryonic day 6 (E6), suggesting translational rather than transcriptional regulation. BTF3 protein was expressed in both somatic and germ cells and was restricted to the medulla of the developing ovary in females and the sex cords of the developing testis in males. In addition, in gonadal sex-reversed females, RNA and protein levels of BTF3 were similar to those normally found in male gonads, suggesting that BTF3 expression correlated with the gonadal phenotype.