Loss of PL6 protein expression in renal clear cell carcinomas and other VHL-deficient tumours

CircRNA RNF10 inhibits tumorigenicity by targeting miR-942-5p/GOLIM4 axis in breast cancer

We aimed to explore the action of a circRNA produced by ring finger protein 10 (circ_RNF10; hsa_circ_0028899) in the malignant behaviors of breast cancer (BC) and to explore its potential action-of-mechanism. The levels of circ_RNF10, miR-942-5p and Golgi integral membrane protein 4 (GOLIM4) were measured through quantitative real-time polymerase chain reaction, western blot, or immunohistochemistry, and the competing endogenous RNA (ceRNA) relationship among them was verified by dual-luciferase reporter assay. Cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and colony formation assays, transwell assays, and flow cytometry were used to examine cell proliferation, migration and invasion, and apoptosis, respectively. Levels of proliferation and invasion-related markers were determined by western blot. Xenograft assay was performed to assess tumor growth. Circ_RNF10 level was significantly reduced in BC tissues and cells. Elevation of circ_RNF10 blocked BC cell proliferation, migration and invasion while promoted the apoptosis in vitro, companied with decreased PCNA and Twist1 and increased E-cadherin. Furthermore, upregulating circ_RNF10 delayed tumor growth of BC cells in nude mice. Mechanistically, circ_RNF10 acted as a ceRNA for miR-942-5p, and miR-942-5p could target GOLIM4. In addition, miR-942-5p overexpression reversed the influence of circ_RNF10 overexpression on BC progression. Furthermore, GOLIM4 silencing attenuated the inhibitory effect of miR-942-5p knockdown on BC progression. We found that circ_RNF10 suppressed BC malignant behavior by targeting miR-942-5p/GOLIM4 axis.

MiR-105-3p acts as an oncogene to promote the proliferation and metastasis of breast cancer cells by targeting GOLIM4

Background

Dysregulated miRNAs are involved in carcinogenesis of the breast and may be used as prognostic biomarkers and therapeutic targets during the cancer process. The purpose of this study was to explore the effect of miR-105-3p on the tumourigenicity of breast cancer and its underlying molecular mechanisms.

Methods

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was applied to detect the expression of miR-105-3p in breast cancer tissues and cell lines. The impacts of miR-105-3p on the proliferation, migration, invasion and apoptosis of human breast cancer cells (MCF-7 and ZR-75-30) were evaluated by CCK-8 assays, Transwell chamber assays, TUNEL assays and western blot analyses. In addition, bioinformatics and luciferase reporter assays were used to determine the target genes of miR-105-3p.

Results

The expression of miR-105-3p was elevated in breast cancer tissues and increased with tumour severity. Downregulation of miR-105-3p could inhibit cell proliferation, suppress cell migration/invasion, and promote cell apoptosis in MCF-7 and ZR-75-30 cells. Furthermore, Golgi integral membrane protein 4 (GOLIM4) was identified as the direct target gene of miR-105-3p by bioinformatics and luciferase reporter assays. In addition, silencing GOLIM4 restored the anti-breast cancer effects induced by miR-105-3p downregulation.

Conclusions

MiR-105-3p acts as an oncogene to promote the proliferation and metastasis of breast cancer cells by targeting GOLIM4, which provides a new target for the prevention and treatment of breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07909-2.

TMEM115 is an integral membrane protein of the Golgi complex involved in retrograde transport

Searching and evaluating the Human Protein Atlas for transmembrane proteins enabled us to identify an integral membrane protein, TMEM115, that is enriched in the Golgi complex. Biochemical and cell biological analysis suggested that TMEM115 has four candidate transmembrane domains located in the N-terminal region. Both the N- and C-terminal domains are oriented towards the cytoplasm. Immunofluorescence analysis supports that TMEM115 is enriched in the Golgi cisternae. Functionally, TMEM115 knockdown or overexpression delays Brefeldin-A-induced Golgi-to-ER retrograde transport, phenocopying cells with mutations or silencing of the conserved oligomeric Golgi (COG) complex. Co-immunoprecipitation and in vitro binding experiments reveals that TMEM115 interacts with the COG complex, and might self-interact to form dimers or oligomers. A short region (residues 206–229) immediately to the C-terminal side of the fourth transmembrane domain is both necessary and sufficient for Golgi targeting. Knockdown of TMEM115 also reduces the binding of the lectins peanut agglutinin (PNA) and Helix pomatia agglutinin (HPA), suggesting an altered O-linked glycosylation profile. These results establish that TMEM115 is an integral membrane protein of the Golgi stack regulating Golgi-to-ER retrograde transport and is likely to be part of the machinery of the COG complex.

Genomic events associated with progression of pleural malignant mesothelioma

Pleural malignant mesothelioma (MM) is an aggressive cancer with a very long latency and a very short median survival. Little is known about the genetic events that trigger MM and their relation to poor outcome. The goal of our study was to characterize major genomic gains and losses associated with MM origin and progression and assess their clinical significance. We performed Representative Oligonucleotide Microarray Analysis (ROMA) on DNA isolated from tumors of 22 patients who recurred at variable interval with the disease after surgery. The total number of copy number alterations (CNA) and frequent imbalances for patients with short time (<12 months from surgery) and long time to recurrence were recorded and mapped using the Analysis of Copy Errors algorithm. We report a profound increase in CNA in the short-time recurrence group with most chromosomes affected, which can be explained by chromosomal instability associated with MM. Deletions in chromosomes 22q12.2, 19q13.32 and 17p13.1 appeared to be the most frequent events (55-74%) shared between MM patients followed by deletions in 1p, 9p, 9q, 4p, 3p and gains in 5p, 18q, 8q and 17q (23-55%). Deletions in 9p21.3 encompassing CDKN2A/ARF and CDKN2B were characterized as specific for the short-term recurrence group. Analysis of the minimal common areas of frequent gains and losses identified candidate genes that may be involved in different stages of MM: OSM (22q12.2), FUS1 and PL6 (3p21.3), DNAJA1 (9p21.1) and CDH2 (18q11.2-q12.3). Imbalances seen by ROMA were confirmed by Affymetrix genome analysis in a subset of samples.

Two novel VHL targets, TGFBI (BIGH3) and its transactivator KLF10, are up-regulated in renal clear cell carcinoma and other tumors

Mutations in the VHL gene are associated with highly vascular tumors of kidney, brain, retina, and adrenal gland. The inability of the mutant VHL protein to destabilize HIF-1 plays a crucial role in malignant angiogenesis. VHL is also associated with ECM assembly but the molecular mechanisms of this activity remain unclear. We used expression arrays and cell lines with different VHL status to identify ECM-associated genes controlled by VHL. One of them, adhesion-associated TGFBI, was repressed by VHL and overexpressed in renal, gastrointestinal, brain, and other tumors. Analyzing the mechanism of TGFBI up-regulation in clear cell carcinoma, we identified a novel VHL target, a Kruppel-like transcriptional factor 10 (KLF10). The TGFBI promoter, which we isolated and studied in Luc-reporter assay, was induced by KLF10 but not hypoxia. These data provide the molecular basis for the observed VHL effect on TGFBI and stimulate further research into the KLF10 and TGFBI roles in cancer.