p38MAPK family isoform p38α and activating transcription factor 2 are associated with the malignant phenotypes and poor prognosis of patients with ovarian adenocarcinoma

p38MAPK Signaling Pathway in Osteoarthritis: Pathological and Therapeutic Aspects

Osteoarthritis (OA) is an aging-related joint disease, pathologically featured with degenerated articular cartilage and deformation of subchondral bone. OA has become the fourth major cause of disability in the world, imposing a huge economic burden. At present, the pathogenesis and pathophysiology of OA are still unclear. Complex regulating networks containing different biochemical signaling pathways are involved in OA pathogenesis and progression. The p38MAPK signaling pathway is a member of the MAPK signaling pathway family, which participates in the induction of cellular senescence, the differentiation of chondrocytes, the synthesis of matrix metalloproteinase (MMPs) and the production of pro-inflammatory factors. In recent years, studies on the regulating role of p38MAPK signaling pathway and the application of its inhibitors have attracted growing attention, with an increasing number of in vivo and in vitro studies. One interesting finding is that the inhibition of p38MAPK could suppress chondrocyte inflammation and ameliorate OA, indicating its therapeutic role in OA treatment. Based on this, we reviewed the mechanisms of p38MAPK signaling pathway in the pathogenesis of OA, hoping to provide new ideas for future research and OA treatment.

Mapk14 is a Prognostic Biomarker and Correlates with the Clinicopathological Features and Immune Infiltration of Colorectal Cancer

Background: Colorectal cancer (CRC) is one of the most common gastrointestinal tumors, ranking in the top 5 of all common tumors in terms of incidence and mortality. However, the mechanisms driving the evolution of colorectal cancer remain unclear. Therefore, we investigated the association between Mapk14 expression and clinicopathological and tumor-infiltrating immune cells.

Methods: In this study, we collected CRC patient data from The Cancer Genome Atlas (TCGA), compared the expression level in CRC and normal colorectal tissue using the Wilcoxon rank sum test and assessed the relationship between Mapk14 and clinicopathological features using the Welch one-way ANOVA test. Kaplan-Meier and timeROC GSE17537 datasets were obtained from the Gene Expression Omnibus (GEO) dataset to assess the prognostic impact of the Mapk14 gene on colorectal cancer. Second, we further explored the methylation level of Mapk14 and its influencing factors. Single-cell sequencing of Mapk14 in the tumor immune microenvironment (TIME) was analyzed using the GSE108989 dataset. Further analyses based on the TIMER method were performed to assess the correlation between Mapk14 and tumor immune infiltration, immune checkpoints, tumor mutational load and microsatellite instability. Finally, the results of the bioinformatics analysis were verified by an immunohistochemical analysis.

Results: The results showed that the expression of Mapk14 was upregulated in CRC tumor tissues compared with normal colorectal tissues and the high expression of Mapk14 was associated with poor clinicopathological features and poor prognoses in the CRC array. In addition, cg05798012 and cg25375420 of Mapk14 are the main DNA methylation sites affecting OS. Single-cell sequencing of the tumor immune microenvironment showed that the abundance and cell state of dysfunctional T cells changed greatly. Importantly, the abnormal overexpression of Mapk14 in colorectal cancer is related to the level of immune infiltration of immune cells (including CD8⁺ T cells, neutrophils, dendritic cells, B cells, CD4⁺ T cells, and macrophages). The high expression of Mapk14 was significantly correlated with immune checkpoints (including SIGLEC15, TIGIT, LAG3, CTLA4 and PDCDILG2), while the high expression of Mapk14 was negatively correlated with TMB and MSI but mostly positively correlated with drug sensitivity. Finally, the immunohistochemical results confirmed that the clinical stage (Ⅰ, Ⅱ, Ⅲ and Ⅳ) and M stage (M0 and M1) affected the abnormally high expression of Mapk14.

Conclusion: A comprehensive bioinformatics study and experimental validation revealed that Mapk14 could serve as a novel prognostic biomarker associated with immune infiltration and pharmacotherapy and may represent a potential therapeutic target for the treatment of CRC.

Research Progress in Prognostic Factors and Biomarkers of Ovarian Cancer

Ovarian cancer is a serious threat to women's health; its early diagnosis rate is low and prone to metastasis and recurrence. The current conventional treatment for ovarian cancer is a combination of platinum and paclitaxel chemotherapy based on surgery. The recurrence and progression of ovarian cancer with poor prognosis is a major challenge in treatment. With rapid advances in technology, understanding of the molecular pathways involved in ovarian cancer recurrence and progression has increased, biomarker-guided treatment options can greatly improve the prognosis of patients. This review systematically discusses and summarizes existing and new information on prognostic factors and biomarkers of ovarian cancer, which is expected to improve the clinical management of patients and lead to effective personalized treatment.

Atorvastatin Attenuates Isoflurane-Induced Activation of ROS-p38MAPK/ATF2 Pathway, Neuronal Degeneration, and Cognitive Impairment of the Aged Mice

Isoflurane, a widely used volatile anesthetic, induces neuronal apoptosis and memory impairments in various animal models. However, the potential mechanisms and effective pharmacologic agents are still not fully understood. The p38MAPK/ATF-2 pathway has been proved to regulate neuronal cell survival and inflammation. Besides, atorvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, exerts neuroprotective effects. Thus, this study aimed to explore the influence of atorvastatin on isoflurane-induced neurodegeneration and underlying mechanisms. Aged C57BL/6 mice (20 months old) were exposed to isoflurane (1.5%) anesthesia for 6 h. Atorvastatin (5, 10, or 20 mg/kg body weight) was administered to the mice for 7 days. Atorvastatin attenuated the isoflurane-induced generation of ROS and apoptosis. Western blotting revealed a decrease in cleaved caspase-9 and caspase-3 expression in line with ROS levels. Furthermore, atorvastatin ameliorated the isoflurane-induced activation of p38MAPK/ATF-2 signaling. In a cellular study, we proved that isoflurane could induce oxidative stress and inflammation by activating the p38MAPK/ATF-2 pathway in BV-2 microglia cells. In addition, SB203580, a selected p38MAPK inhibitor, inhibited the isoflurane-induced inflammation, oxidative stress, and apoptosis. The results implied that p38MAPK/ATF-2 was a potential target for the treatment of postoperative cognitive dysfunction.

Knockdown of MAPK14 inhibits the proliferation and migration of clear cell renal cell carcinoma by downregulating the expression of CDC25B

Mitogen‐activated protein kinase 14 (MAPK14), which plays an important role in DNA damage and repair, is activated by various environmental stress and proinflammatory cytokines. It is highly active in a variety of tumors, acting as a tumor promoter or suppressor, but its role in clear cell renal cell carcinoma (ccRCC) has not been elucidated. Cell division cycle 25B (CDC25B) is involved in cell cycle regulation and is highly expressed in many malignant tumors. The transcription levels of MAPK14 and CDC25B in 72 pairs of ccRCC and adjacent healthy tissues from the cancer genome atlas database and the protein expression levels in 66 pairs of clinical samples were analyzed in this study. After MAPK14 was knocked down by small interfering RNA (siRNA), P‐MAPK14 and CDC25B protein levels decreased. Subsequently, Western blot and co‐immunoprecipitation demonstrated that P‐MAPK14 could bind to CDC25B, potentially maintaining its stability. The proliferation and migration of ccRCC cell lines were suppressed by siRNA knockdown of MAPK14, however, that could be partially reversed by the overexpression of CDC25B. These results suggest that downregulation of MAPK14 and P‐MAPK14 could inhibit the proliferation and migration of ccRCC by downregulating CDC25B.

Off-target toxicity is a common mechanism of action of cancer drugs undergoing clinical trials

Ninety-seven percent of drug-indication pairs that are tested in clinical trials in oncology never advance to receive U.S. Food and Drug Administration approval. While lack of efficacy and dose-limiting toxicities are the most common causes of trial failure, the reason(s) why so many new drugs encounter these problems is not well understood. Using CRISPR-Cas9 mutagenesis, we investigated a set of cancer drugs and drug targets in various stages of clinical testing. We show that-contrary to previous reports obtained predominantly with RNA interference and small-molecule inhibitors-the proteins ostensibly targeted by these drugs are nonessential for cancer cell proliferation. Moreover, the efficacy of each drug that we tested was unaffected by the loss of its putative target, indicating that these compounds kill cells via off-target effects. By applying a genetic target-deconvolution strategy, we found that the mischaracterized anticancer agent OTS964 is actually a potent inhibitor of the cyclin-dependent kinase CDK11 and that multiple cancer types are addicted to CDK11 expression. We suggest that stringent genetic validation of the mechanism of action of cancer drugs in the preclinical setting may decrease the number of therapies tested in human patients that fail to provide any clinical benefit.

Insights of Crosstalk between p53 Protein and the MKK3/MKK6/p38 MAPK Signaling Pathway in Cancer

TP53 is universally recognized as a pivotal protein in cell-cycle fate and apoptotic induction and, unsurprisingly, it is one of the most commonly hijacked control mechanisms in cancer. Recently, the kinase MKK3 emerged as a potential therapeutic target in different types of solid tumor being linked to mutant p53 gain-of-function. In this review, we summarize the delicate relationship among p53 mutational status, MKK3/MKK6 and the downstream activated master kinase p38MAPK, dissecting a finely-tuned crosstalk, in a potentially cell-context dependent scenario that urges towards a deeper characterization of the different molecular players involved in this signaling cascade and their interactions.