Engagement of programmed death-ligand 1 (PD-L1) with its receptor programmed death 1 (PD-1) on T cells has been speculated to play a major role in suppressing the immune system, which helps tumor cells evade anti-tumor immunity. With the development of whole genome sequencing technologies, microRNAs have gained more attention as an important new layer of molecular regulation. Recent studies have revealed that altered expression of microRNAs play a pivotal role in immune checkpoint and various cellular processes in cancer. In this review, we focused on the latest progress about microRNAs research which involves the regulation of PD-1/PD-L1 immune checkpoint.
Matrix metallopeptidase 9 (MMP9) was found to be associated with tumor aggressiveness. In this study, we focused on the correlation between MMP9 expression and clear cell renal carcinoma (ccRCC). Through the Gene Expression Omnibus (GEO) database, the Cancer Genome Atlas (TCGA) database and immunohistochemical (IHC) staining, we observed that compared with adjacent normal renal tissues, in ccRCC tissues the mRNA and protein levels of MMP9 were enhanced, and the mRNA levels of GTP-binding protein smg p21B(RAP1B), B rapidly accelerated fibrosarcoma (RAF), methyl ethyl ketone2 (MEK2), extracellular regulated protein kinases1 (ERK1), ERK2, v-ets avian erythroblastosis virus E26 oncogene homolog1 (ETS1) and ETS2 also increased. The Kaplan–Meier survival analysis suggested that high MMP9 expression was an unfavorable prognostic biomarker for ccRCC patients. Our results indicated that the increased expression level of MMP9 in ccRCC may be due to the activation of the Mitogen-activated protein kinases (MAPK)/ERK signaling pathway, and MMP9 may be an attractive target for ccRCC therapy.
The death-associated protein kinase 1 (DAPK1) can act as an oncogene or a tumor suppressor gene depending on the cellular context as well as external stimuli. Our study aims to investigate the prognostic significance of DAPK1 in liver cancer in both mRNA and protein levels. The mRNA expression of DAPK1 was extracted from the Gene Expression Omnibus database in three independent liver cancer datasets while protein expression of DAPK1 was detected by immunohistochemistry in our Chinese liver cancer patient cohort. The associations between DAPK1 expression and clinical characteristics were tested. DAPK1 mRNA expression was down-regulated in liver cancer. Low levels of DAPK1 mRNA were associated with shorter survival in a liver cancer patient cohort (n = 115; p = 0.041), while negative staining of DAPK1 protein was significantly correlated with shorter time to progression (p = 0.002) and overall survival (p = 0.02). DAPK1 was an independent prognostic marker for both time to progression and overall survival by multivariate analysis. Liver cancer with the b-catenin mutation has a lower DAPK1 expression, suggesting that DAPK1 may be regulated under the b-catenin pathway. In addition, we also identified genes that are co-regulated with DAPK1. DAPK1 expression was positively correlated with IRF2, IL7R, PCOLCE and ZBTB16, and negatively correlated with SLC16A3 in both liver cancer datasets. Among these genes, PCOLCE and ZBTB16 were significantly down-regulated, while SLC16A3 was significantly upregulated in liver cancer. By using connectivity mapping of these co-regulated genes, we have identified amcinonide and sulpiride as potential small molecules that could potentially reverse DAPK1/PCOLCE/ZBTB16/SLC16A3 expression. Our study demonstrated for the first time that both DAPK1 mRNA and protein expression levels are important prognostic markers in liver cancer, and have identified genes that may contribute to DAPK1-mediated liver carcinogenesis.
Background: Breast cancer is one of the most common tumors for women globally. Various miRNAs have been reported to play a crucial role in breast cancer, however the clinical significance of miR-1908-3p in breast cancer remains unclear. The present study aimed to explore the role of miR-1908-3p in breast cancer. Methods: The expression of miR-1908-3p was detected in 50 pairs of breast cancer tissues and adjacent normal tissues, 60 breast cancer patient serum and 60 healthy volunteer serum. The functional roles of miR-1908-3p in breast cancer cells such as proliferation, migration and invasion were evaluated using CCK8, SRB, wound healing and transwell chambers. In addition, bioinformatics tools were used to identify potential targets of miR-1908-3p. Results: The results showed that the expression of miR-1908-3p were increased in breast cancer tissues and serum compared with normal breast tissues and serum of healthy volunteers respectively. Furthermore, the young breast cancer patients and HER2-positive patients had a higher level of tissues' miR-1908-3p than elder breast cancer patients and HER2-negative patients, respectively. The young breast cancer patients had a higher level of serum miR-1908-3p than elder breast cancer patients, ROC analysis suggested that miR-1908-3p had the potential as a promising serum diagnostic biomarker of breast cancer. Up-regulation of miR-1908-3p promoted the cells proliferation, migration and invasion while knockdown of miR-1908-3p inhibited these processes in breast cancer cell MCF-7 and MDA-MB-231. The potential target genes of miR-1908-3p in breast cancer included ID4, LTBP4, GPM6B, RGMA, EFCAB1, ALX4, OSR1 and PPARA. Higher expression of these eight genes correlated with a better prognosis for breast cancer patients. Conclusions: These results suggest that miR-1908-3p may exert its oncogenic functions via suppression of these eight genes in breast cancer.
To determine the proteomic response to UV irradiation, two cultivars, i.e., Lemont (UV tolerant) and Dular (UV sensitive), were exposed to natural and enhanced ultraviolet-B (UV-B) irradiation for 1, 7, and 14 days, and two-dimensional gel electrophoresis in combination with mass spectrometry (MS) and bioinformatics were used to compare the different proteomic responses in the leaves of the two cultivars. Thirty-nine proteins were up-or downregulated following the UV-B treatments. Among them, 30 increased or decreased more than 1.5-fold in abundance. They were further tested by using matrix-assisted laser desorption/ionization time of flight MS and performed a database search. Twentyfour proteins were thus identified. These identified proteins were mostly upregulated in Lemont, whereas only 14 of them upregulated in Dular. Nine proteins involved in glycometabolism and fatty acid metabolisms, signal transduction, and protein synthesis and folding in Dular were not changed. These results suggest that there was a complex regulative mechanism on the proteomes in rice leaves upon UV-B exposure.
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