CA8 promotes RCC proliferation and migration though its expression level is lower in tumor compared to adjacent normal tissue

Mitochondrial DNA copy number reduction via in vitro TFAM knockout remodels the nuclear epigenome and transcriptome

Mitochondrial DNA copy number (mtDNA-CN) is associated with several age-related chronic diseases and is a predictor of all-cause mortality. Here, we examine site-specific differential nuclear DNA (nDNA) methylation and differential gene expression resulting from in vitro reduction of mtDNA-CN to uncover shared genes and biological pathways mediating the effect of mtDNA-CN on disease. Epigenome and transcriptome profiles were generated for three independent human embryonic kidney (HEK293T) cell lines harbouring a mitochondrial transcription factor A (TFAM) heterozygous knockout generated via CRISPR-Cas9, and matched control lines. We identified 4,242 differentially methylated sites, 228 differentially methylated regions, and 179 differentially expressed genes associated with mtDNA-CN. Integrated analysis uncovered 381 Gene-CpG pairs. GABAA receptor genes and related pathways, the neuroactive ligand receptor interaction pathway, ABCD1/2 gene activity, and cell signalling processes were overrepresented, providing insight into the underlying biological mechanisms facilitating these associations. We also report evidence implicating chromatin state regulatory mechanisms as modulators of mtDNA-CN effect on gene expression. We demonstrate that mitochondrial DNA variation signals to the nuclear DNA epigenome and transcriptome and may lead to nuclear remodelling relevant to development, aging, and complex disease.

A promising anoikis-related prognostic signature predicts prognosis of skin cutaneous melanoma

BACKGROUND

Skin cutaneous melanoma (SKCM) is a highly aggressive disease with a poor prognosis for advanced tumors. Anoikis is a caspase-dependent cell death process triggered by extracellular matrix (ECM) detachment, rectifies detachment-induced metabolic defects that compromise cell survival, recent study revealed the crucial role of anoikis for cancer cells to survive during metastasis. However, limited research focused on the role of anoikis in SKCM.

METHODS

Our study utilized the 27 anoikis-related genes (ARGs) to divide SKCM patients into two clusters, and obtain differentially expressed genes (DEGs) for each cluster. These DEGs were used in stepwise Cox regression analysis to develop a prediction model for SKCM patients consisting of nine ARGs, called the anoikis-related signature (ARS). Subsequently, we used the risk scores calculated from the ARS to divide SKCM patients into two groups and explored differences in immune microenvironment, immune checkpoint reactivity, and drug sensitivity between the groups.

RESULTS

Nine ARGs were identified to stratify SKCM patients into two risk groups, patients in the high-risk group had a poor prognosis and suppressed immune cell infiltration. Moreover, higher expression of immune checkpoint molecules and a greater sensitivity to immunotherapy and chemotherapy drugs were observed in the low-risk group. Finally, all of the ARS hub genes were found to be upregulated in SKCM tissues and cell lines.

CONCLUSION

A novel ARGs signature was identified for predicting the prognosis of SKCM. Based on the immune landscape associated with ARS discovered in our study, targeting ARS hub genes may be a promising treatment for SKCM.

WISP1 induces ovarian cancer via the IGF1/αvβ3/Wnt axis

Background

This study intended to clarify the mechanisms by which WISP1-mediated IGF1/αvβ3/Wnt axis might affect the progression of ovarian cancer.

Methods

Bioinformatics analysis was implemented for pinpointing expression of IGF1 and WISP1 which was verified through expression determination in clinical tissue samples and cells. Next, gain- or loss-of-function experimentations were implemented for testing CAOV4 and SKOV3 cell biological processes. The interaction between WISP1 and IGF1 was verified by co-immunoprecipitation and the molecular mechanism was analyzed. Finally, ovarian cancer nude mouse models were prepared to unveil the in vivo effects of WISP1/IGF1.

Results

IGF1 and WISP1 expression was elevated in ovarian cancer tissues and cells, which shared correlation with poor prognosis of ovarian cancer sufferers. Elevated IGF1 induced malignant properties of ovarian cancer cells through activation of PI3K-Akt and Wnt signaling pathway. WISP1 was positively correlated with IGF1. WISP1 could enhance the interaction between IGF1 and αvβ3 to induce epithelial-mesenchymal transition. In vivo experiments also confirmed that upregulated WISP1/IGF1 induced tumorigenesis and metastasis of ovarian cancer cells.

Conclusion

In conclusion, WISP1 can facilitate ovarian cancer by activating Wnt via the interaction between IGF1 and αvβ3.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-01016-x.

Mxi1 participates in the progression of lung cancer via the microRNA-300/KLF9/GADD34 Axis

The purpose of the current study was to define the role of MAX interactor 1 (Mxi1) in the pathogenesis of lung cancer and its underlying molecular mechanism. Bioinformatics analysis was performed to identify important regulatory pathway related to lung cancer. Dual luciferase reporter and ChIP assays were adopted to validate the interaction among Mxi1, miR-300 and KLF9. Loss- and gain-of-function studies were conducted to determine the roles of Mxi1, miR-300, and KLF9 in cell proliferation, migration, and invasion in vitro and their effects on myeloid-derived suppressor cell (MDSC) recruitment in vivo. Mxi1 was poorly expressed in lung cancer tissues and cells and its poor expression was associated with poor prognosis. Mxi1 inhibited miR-300 by suppressing its transcription. miR-300 suppressed the expression of KLF9, and KLF9 negatively regulated GADD34 expression in lung cancer cells. Mxi1 or KLF9 elevation or miR-300 repression inhibited lung cancer cell proliferation, as evidenced by reduced Ki67 and PCNA expression, and lowered invasion and migration. In vivo findings revealed that silencing KLF9 induced tumor growth by enhancing MDSC-mediated immunosuppression through upregulation of GADD34. Collectively, these findings suggest that Mxi1 can inhibit lung cancer progression by regulating the miR-300/KLF9 axis and GADD34-mediated immunosuppression.

Carbonic Anhydrase VIII (CAVIII) Gene Mediated Colorectal Cancer Growth and Angiogenesis through Mediated miRNA 16-5p

Carbonic anhydrase VIII (CAVIII) is a member of the CA family, while CA8 is the oncogene. Here we observed increased expression of CAVIII with high expression in colorectal cancer tissues. CAVIII is also expressed in more aggressive types of human colorectal cancer cells. Upregulated CAVIII expression in SW480 cell lines increased vascular endothelial growth factor (VEGF) and reduced miRNA16-5p. Conversely, knockdown of the CAVIII results in VEGF decline by up-regulated miRNA16-5p. Moreover, the collection of different grades of CAVIII expression CRC cells supernatant co-culture with endothelial progenitor cells (EPCs) promotes the ability of tube formation in soft agar and migration in the Transwell experiment, indicating that CAVIII might facilitate cancer-cell-released VEGF via the inhibition of miRNA16-5p signaling. Furthermore, in the xenograft tumor angiogenesis model, knockdown of CAVIII significantly reduced tumor growth and tumor-associated angiogenesis. Taken together, our results prove that the CAVIII/miR-16-5p signaling pathway might function as a metastasis suppressor in CRC. Targeting CAVIII/miR-16-5p may provide a strategy for blocking its metastasis.

Inhibition of FSTL3 abates the proliferation and metastasis of renal cell carcinoma via the GSK-3β/β-catenin signaling pathway

Renal cell carcinoma (RCC) is a lethal malignancy of the genitourinary system. Follistatin-like 3 (FSTL3), which mediates cell differentiation and growth, acts as a biomarker of tumors and participates in cancer development and progression. Presently, the FSTL3’s functions in RCC were investigated. Quantitative reverse transcription PCR (qRT-PCR), Western Blot, and enzyme linked immunosorbent assay (ELISA) were conducted to verify FSTL3 expression in RCC tissues and cell lines. BrdU assay and CCK8 experiment were made to monitor cell proliferation. Transwell was implemented to examine the invasion of the cells. Flow cytometry analyzed cell apoptosis, and Western Blot evaluated the protein levels of E-cadherin, Twist, and Slug. In the meantime, the protein profiles of the GSK-3β, β-catenin, and TGF-β signaling pathways were ascertained. Moreover, the Xenograft tumor model was constructed in nude mice for measuring tumor growth in vivo. The statistics showed that FSTL3 presented an overexpression in RCC, and patients with a lower expression of FSTL3 manifested a better prognosis. Down-regulated FSTL3 hampered the proliferation, invasion, EMT, and tumor growth of RCC cells and caused cell apoptosis. On the contrary, FSTL3 overexpression enhanced the malignant behaviors of RCC cells. Furthermore, FSTL3 knockdown bolstered GSK-3β, suppressed β-catenin, and reduced BMP1-SMAD pathway activation. Inhibited β-catenin substantially mitigated FSTL3-mediated promoting functions in RCC. In short, FSTL3 functions as an oncogene in RCC by modulating the GSK-3β/β-catenin signaling pathway.

DNA methylation mediated down-regulation of ANGPTL4 promotes colorectal cancer metastasis by activating the ERK pathway

Background: Colorectal cancer (CRC) imposes significant health burden and is increasing in incidence. NGPTL4 has been implicated in the development of CRC. The present study aimed to investigate the molecular mechanisms by which ANGPTL4 expression might regulate epithelial-mesenchymal transition (EMT) and the tumor microenvironment in CRC.

Methods: CRC and para-carcinoma tissues were collected from 67 CRC patients. ANGPTL4 expression levels and DNA methylation of ANGPTL4 promoter region were determined. Next, the migration and invasion capacities of CRC cells were assessed. Immunofluorescence and Western blot were used to identify the signaling pathways by which ANGPTL4 mediated tumor metastasis. A tumorigenesis mice model with transplanted fibroblast cells and ANGPTL4 overexpressed CRC cells was established to investigate the effects of ANGPTL4 on the metastasis of cancer cells in vivo.

Results: ANGPTL4 was significantly decreased in CRC tissues and DNA hypermethylation was involved in the regulation of ANGPTL4. Mechanistically, ANGPTL4 induced activation of cancer-associated fibroblasts in the tumor microenvironment and promoted EMT in CRC cells through the ERK signaling pathway. In vivo, the overexpression of ANGPTL4 was found to inhibit the metastasis of tumor cells in lung tissues.

Conclusion: DNA hypermethylation induced ANGPTL4 downregulation promoted the activation of cancer-associated fibroblasts and epithelial mesenchymal transformation of CRC cells via the ERK signaling pathway, thereby promoting invasion and metastasis in CRC.

RB1CC1 functions as a tumor-suppressing gene in renal cell carcinoma via suppression of PYK2 activity and disruption of TAZ-mediated PDL1 transcription activation

Rb1-inducible coiled-coil 1 (RB1CC1) has been demonstrated to function as an inhibitor of proline-rich/Ca-activated tyrosine kinase 2 (PYK2) by binding to the kinase domain of PYK2, which promotes the proliferation, invasion, and migration of renal cell carcinoma (RCC) cells. Additionally, in breast cancer, PYK2 positively regulates the expression of transcriptional co-activator with PDZ-binding motif (TAZ) which in turn can enhance PDL1 levels in breast and lung cancer cells. The current study was performed to decipher the impact of RB1CC1 in the progression of RCC via regulation of the PYK2/TAZ/PDL1 signaling axis. Expression of RB1CC1 and PYK2 was quantified in clinical tissue samples from RCC patients. The relationship between TAZ and PYK2, TAZ and PDL1 was then validated. The cellular processes of doxorubicin (DOX)-induced human RCC cell lines including the abilities of proliferation, colony formation, sphere formation and apoptosis, as well as the tumorigenicity of transfected cells, were evaluated after the alteration of RB1CC1 expression. RB1CC1 exhibited decreased expression in RCC tissues and was positively correlated with patient survival. RB1CC1 could inhibit the activity of PYK2, which in turn stimulated the stability of TAZ protein by phosphorylating TAZ. Meanwhile, TAZ protein activated PDL1 transcription by binding to the promoter region of PDL1. RB1CC1 overexpression or PYK2 knockdown could help everolimus (EVE) to inhibit tumor proliferation and activate immune response. Taken together, RB1CC1 can potentially augment the response of RCC cells to immunotherapy by suppressing the PYK2/TAZ/PDL1 signaling axis.

KDM3B-ETF1 fusion gene downregulates LMO2 via the WNT/β-catenin signaling pathway, promoting metastasis of invasive ductal carcinoma

Breast cancer is the most common malignancy for women, with invasive ductal carcinoma being the largest subtype of breast cancers, accounting for 75-80% of cases. However, the underlying mechanism of invasive ductal carcinoma remains unclear. In this study, we investigate the possible effects KDM3B-ETF1 fusion gene has on breast cancer cell metastasis, invasion and its downstream signaling mediators as revealed from RNA sequence data analysis. As predicted, KDM3B-ETF1 expression was increased in breast cancer tissues and cells. Overexpression of KDM3B-ETF1 in cancer cell lines promoted the growth and invasion of breast cancer cells, while KDM3B-ETF1 knockdown showed the opposite effects on malignant cell growth and invasion both in vivo and in vitro as evidenced by cell counting kit-8, Transwell assay and tumor xenograft in nude mice. On the contrary, LIM Domain Only 2 (LMO2) expression was significantly reduced in breast cancer tissues and cells. According to chromatin immunoprecipitation and Western blot analysis, KDM3B-ETF1 targets LMO2 and reduced the expression of LMO2, leading to an increase in WNT/β-catenin signaling pathway and thus promoting invasion. In conclusion, fusion gene KDM3B-ETF1 inhibits LMO2, activates the Wnt/β-catenin signaling pathway that leads to increased breast cancer cell invasion and metastasis, providing a novel insight into developing therapeutic strategies. These results provide novel insights into the molecular mechanism of invasive ductal carcinomas, which may lead to potential therapeutic targets.

MicroRNA let-7i Inhibits Histone Lysine Demethylase KDM5B to Halt Esophageal Cancer Progression

Recent studies have suggested that microRNA let-7i is a tumor suppressor in human cancers, including esophageal cancer, but its underlying mechanism is not yet fully understood. We investigated the role and mechanisms of let-7i in the progression of esophageal cancer. We first showed that let-7i was downregulated in esophageal cancer tissues and cells and then linked its low expression to cancer progression. Bioinformatic analysis predicted KDM5B as a target gene of let-7i, which was confirmed by a dual-luciferase reporter assay. Loss- and gain-of function approaches were adopted to examine the interactions of let-7i, KDM5B, SOX17, and GREB1 in vitro and in vivo. Overexpression of let-7i suppressed esophageal cancer cell proliferation and invasion and promoted apoptosis. Mechanistic investigation showed that let-7i targeted and inhibited KDM5B expression, whereas KDM5B enhanced H3K4me3 at the SOX17 promoter region. Overexpression of let-7i suppressed the expression of GREB1 in esophageal cancer cells by regulating the KDM5B/SOX17 axis in vivo and in vitro. Taken together, our findings reveal the tumor-suppressive properties of let-7i in esophageal cancer in association with an apparent KDM5B-dependent SOX17/GREB1 axis. This study offers a potential prognostic marker and therapeutic target for esophageal cancer.

Keratin 17 Suppresses Cell Proliferation and Epithelial-Mesenchymal Transition in Pancreatic Cancer

Keratin 17 (K17), a member of type I acidic epithelial keratin family, has been reported to be upregulated in many malignant tumors and to be involved in promoting the development of tumors. However, the precise role of K17 in progression of pancreatic cancer is still unknown. In this study, we found that K17 expression was highly expressed in pancreatic cancer tissues and cell lines and that upregulated expression was associated with the pathological grade and poor prognosis. K17 expression served as an independent predictor of pancreatic cancer survival. Meanwhile, we showed that knocking down K17 induced pancreatic cancer cell proliferation, colony formation and tumor growth in xenografts in mice. However, K17 upregulation inhibited pancreatic cancer cell proliferation and colony formation. Further mechanistic study revealed that K17 knockdown promoted cell cycle progression by upregulating CyclinD1 expression and repressed cell apoptosis. However, K17 upregulation suppressed cell cycle progression by decreasing CyclinD1 expression, and induced apoptosis by increasing the levels of cleaved Caspase3. In addition, K17 knockdown promoted pancreatic cancer cell migration and invasion, but K17 upregulation suppressed cell migration and invasion. Moreover, knocking down K17 promoted epithelial-mesenchymal transition (EMT) in pancreatic cancer cell by inhibiting E-cadherin expression and inducing Vimentin expression, and the effects of K17 upregulation were opposite to that of K17downregulation. Taken together, our findings suggest that K17 functions as a potential tumor suppressor, even though it is upregulated in pancreatic cancer.

Genistein inhibited the proliferation of kidney cancer cells via CDKN2a hypomethylation: role of abnormal apoptosis

INTRODUCTION

Genistein is recognized as a potent anti-oxidant in soybean-enriched foods, which is a kind of phytoestrogen involved in anticancer activity in various cancers.

OBJECTIVE

The objective of this study was to investigate the molecular mechanism of CDKN2a hypomethylation involved in the anti-tumor effect of genistein on kidney cancer.

METHODS

The CDKN2a expression was measured using qRT-PCR. The level of CDKN2a methylation was detected using methylation-specific PCR. The apoptosis was detected via flow-cytometric analysis. The cell viability was detected using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

RESULTS

Our results indicated that genistein induced cell apoptosis and inhibited the cell proliferation of kidney cancer cells. Moreover, genistein increased the expression of CDKN2a and decreased CDKN2a methylation.

CONCLUSIONS

Our results demonstrated that the anti-tumor effect of genistein might induce cell apoptosis and inhibit the proliferation of kidney cancer cells via regulating CDKN2a methylation.