Phosphorylation of Bcl-2 by JNK confers gemcitabine resistance in lung cancer cells by reducing autophagy-mediated cell death

DSG2 attenuates gemcitabine efficacy through PTX3 in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the most prevalent subtype of lung cancer, often diagnosed at an advanced stage with poor prognosis and limited treatment options. The Desmoglein (DSG) family plays a crucial role in maintaining cell adhesion and tissue integrity. Upregulation of DSG proteins has been implicated in tumorigenesis, invasion, and metastasis across various cancers. However, the role of DSG in lung cancer, particularly as a biomarker influencing the efficacy of anti-cancer drugs, remains unclear. In this study, DSG2 was significantly overexpressed in LUAD tumor tissues and correlated with poor prognosis, as revealed by TCGA database analysis. Additionally, analyses of single-cell sequencing, KEGG, and GSEA multi-omics databases demonstrated that DSG2 modulates multiple oncogenic pathways, particularly the apoptosis pathway, with a strong positive correlation between DSG2 and PTX3 expression. In vitro experiments showed that DSG2 knockdown enhanced gemcitabine-induced apoptosis by downregulating the NFκB/STAT3/PTX3 signaling axis. Furthermore, adding recombinant PTX3 protein in DSG2 knockdown cells restored STAT3 activation, reducing gemcitabine efficacy, indicating that DSG2 contributes to gemcitabine resistance through PTX3-mediated mechanisms. This study identifies DSG2 as a critical mediator of gemcitabine resistance in LUAD through its regulation of the PTX3/NFκB/STAT3 pathway. The findings suggest that targeting DSG2 could enhance the therapeutic efficacy of gemcitabine in LUAD patients, offering a novel therapeutic strategy and biomarker for overcoming chemoresistance in this aggressive cancer subtype.

Artemisia argyi mitigates doxorubicin-induced cardiotoxicity by inhibiting mitochondrial dysfunction through the IGF-IIR/Drp1/GATA4 signaling pathway

Doxorubicin (DOX) is mostly utilized as a wide range of antitumor anthracycline to treat different cancers. The severe antagonistic impacts of DOX on cardiotoxicity constrain its clinical application. Many mechanisms are involved in cardiac toxicity induced by DOX in the human body. Mitochondria is a central part of fatty acid and glucose metabolism. Thus, impaired mitochondrial metabolism can increase heart failure risk, which can play a vital role in cardiomyocyte mitochondrial dysfunction. This study aimed to assess the possible cardioprotective effect of water-extracted Artemisia argyi (AA) against the side effect of DOX in H9c2 cells and whether these protective effects are mediated through IGF-IIR/Drp1/GATA4 signaling pathways. Although several studies proved that AA extract has benefits for various diseases, its cardiac effects have not yet been identified. The H9c2 cells were exposed to 1 μM to establish a model of cardiac toxicity. The results revealed that water-extracted AA could block the expression of IGF-IIR/calcineurin signaling pathways induced by DOX. Notably, our results also showed that AA treatment markedly attenuated Akt phosphorylation and cleaved caspase 3, and the nuclear translocation markers NFATC3 and p-GATA4. Using actin staining for hypertrophy, we determined that AA can reduce the effect of mitochondrial reactive oxygen species and cell size. These findings suggest that water-extracted AA could be a suitable candidate for preventing DOX-induced cardiac damage.

Mitogen-Activated Protein Kinase Phosphatase-2 Deletion Promotes Hyperglycemia and Susceptibility to Streptozotocin-Induced Diabetes in Female Mice In Vivo

The development of type 2 diabetes (T2D) is largely dependent on the maintenance of pancreatic islet function and mass. Sexual dimorphism in T2D is evident in many areas, such as pathophysiology, treatment, and prevention. Mitogen-activated protein kinase phosphatase-2 (MKP-2) has a distinct role in the regulation of cell proliferation and the development of metabolic disorders. However, whether there is a causal relationship between MKP-2 and diabetes onset is unclear. The aim of this study was to determine the role of MKP-2 in the regulation of whole-body glucose homeostasis and the impact on pancreatic islet function using streptozotocin-induced pancreatic injury. Here, we show that female mice with whole-body deletion of MKP-2 exhibit hyperglycemia in mouse models treated with multiple low doses of streptozotocin (STZ). In comparison, both male MKP-2 wild-type and knockout mice were hyperglycemic. Consistent with the hyperglycemia, female MKP-2-deficient mice exhibited reduced islet size. Under T2D conditions, MKP-2-deficient mice display enhanced pancreatic JNK and ERK phosphorylation that is associated with the downregulation of genes important for pancreatic islet development and function, Pdx-1 and MafA. Furthermore, we found impaired metabolic flux in adipose tissue that is consistent with hyperglycemia and dysfunctional pancreas. MKP-2 deletion results in reduced Akt activation that is associated with increased adiposity and insulin resistance in female MKP-2 KO mice. These studies demonstrate the critical role of MKP-2 in the development of T2D diabetes in vivo. This suggests that MKP-2 may have a gender-specific role in diabetes development. This discovery raises the possibility that postmenopausal prevention of T2D may benefit from the activation of MKP-2 activity in islet cells.

Impact of C-FOS/C-JUN Transcriptional Factors Co-Expression in Non-small Cell Lung Carcinoma

Background/Aim

Significant transcription factors - including c-Fos (gene locus: 14q24.3) and c-Jun (gene locus: 1p32-p31) - regulate cell homeostasis preventing abnormal signal transduction to nucleus. Their over-activation seems to be associated with an aggressive phenotype in non-small cell lung carcinomas (NSCLCs). In the current study, our aim was to co-analyze c-FOS/c-JUN protein expression in a series of NSCLCs correlating them to the corresponding clinico-pathological features.

Materials and Methods

A set of fifty (n=50) paraffin embedded NSCLC tissue sections were selected comprising of adenocarcinomas (n=25) and squamous cell carcinomas (n=25), respectively. Immunocytochemistry (IHC) for the c-FOS/c-JUN markers was implemented. Digital image analysis (DIA) was also performed for evaluating objectively the corresponding immunostaining intensity levels of the examined proteins.

Results

All the examined tissue samples expressed the markers in different protein levels. High staining intensity levels were detected in 34/50 (68%) and 24/50 (48%), respectively. C-FOS over expression was statistically significant correlated to stage (p=0.033), whereas C-JUN over expression was associated with NSCLC histotype (p=0.05) and with maximum tumor diameter (p=0.046).

Conclusion

C-FOS/C-JUN co- over activation is observed frequently in NSCLC, playing potentially a central role in the aggressiveness of the malignancy's phenotype (advanced stage, increased metastatic potential). Development and implementation of novel agents that target these transcription factors is a promising approach for applying targeted therapeutic strategies in NSCC patients based on specific genetic signatures and protein profiles.

Proteomic characterization of extracellular vesicles in programmed cell death

Programmed cell death (PCD) is a fundamental biological process that plays a critical role in cell development, differentiation, and homeostasis. The secretion and uptake of extracellular vesicles (EVs) is one of the important regulatory mechanisms for PCD. EVs are natural membrane structures secreted by cells that contain a variety of proteins, lipids, nucleic acids, and other bioactive molecules. Due to their important roles in intercellular communication and disease progression, there is great interest in studying EVs and their cargo. Different protein components are sorted and packaged in EVs, allowing EVs to perform their functions. The study of EV proteomics helps us understand the role of PCD in the development of diseases. Meanwhile, proteomics is a powerful tool for studying the composition and function of EVs, which assists in the identification, quantification, and profiling of protein components of EVs, and provides insight into the molecular mechanisms involved in PCD and related diseases. In this review, we summarize the characteristics of EV proteomics in different types of PCD, compare different proteomic profiling strategies for EVs, and discuss the impact of EV proteomics on cell function and regulation during PCD, to understand its role in the pathogenesis of related diseases.