From Androgen Dependence to Independence in Prostate Cancer: Unraveling Therapeutic Potential and Proteomic Landscape of Hydroxychloroquine as an Autophagy Inhibitor.

Prostate cancer is a major planetary health challenge wherein new ways of thinking drug discovery and therapeutics innovation are much needed. Numerous studies have shown that autophagy inhibition holds a significant role as an adjunctive intervention in prostate cancer. Hydroxychloroquine (HCQ) has gained considerable attention due to its established role as an autophagy inhibitor across diverse cancer types, but its proteomics landscape and systems biology in prostate cancer are currently lacking in the literature. This study reports the proteomic responses to HCQ in prostate cancer cells, namely, androgen-dependent LNCaP and androgen-independent PC3 cells. Differentially expressed proteins and proteome in HCQ-treated cells were determined by label-free quantification with nano-high-performance liquid chromatography and tandem mass spectrometry (nHPLC-MS/MS), and harnessing bioinformatics tools. In PC3 cells, there was a marked shift toward metabolic reprogramming, highlighted by an upregulation of mitochondrial proteins in oxidative phosphorylation and tricarboxylic acid cycle, suggesting an adaptive mechanism to maintain energy production under therapeutic stress. In contrast, LNCaP cells prioritized proteostasis and cell cycle regulation, indicating a more conservative adaptation strategy. To the best of our knowledge, this study is the first to demonstrate the differential responses of prostate cancer cells to autophagy inhibition by HCQ, suggesting that a combination therapy approach, targeting distinct pathways in androgen-independent and androgen-dependent cells, could represent a promising treatment strategy. Moreover, the varied proteomic responses observed between these cell lines underscore the importance of personalized medicine in cancer therapy. Future translational and clinical research on HCQ and prostate cancer are called for.

Synergistic effect of a nonsteroidal anti-inflammatory drug in combination with topotecan on small cell lung cancer cells.

BACKGROUND: The topoisomerase I inhibitor topotecan (TPT) is used in the treatment of recurrent small cell lung cancer (SCLC). However, the drug has a limited success rate and causes distress to patients due to its side effects, such as hematologic toxicities, including anemia and thrombocytopenia. Due to these pharmacokinetic limitations and undesirable side effects of chemotherapeutic drugs, the development of combination therapies has gained popularity in SCLC. Meclofenamic acid (MA), a nonsteroidal anti-inflammatory drug, has demonstrated anticancer effects on various types of cancers through different mechanisms. This study aims to investigate the potential synergistic effects of MA and TPT on the small cell lung cancer cell line DMS114. METHODS AND RESULTS: To assess the cytotoxic and apoptotic effects of the combined treatment of MA and TPT, trypan blue exclusion assay, Annexin V, acridine orange/propidium iodide staining, western blot, and cell cycle analysis were conducted. The results demonstrated that the combination of MA and TPT elicited synergistic effects by enhancing toxicity in DMS114 cells (P < 0.01) without causing toxicity in healthy epithelial lung cells MRC5. The strongest synergistic effect was observed when the cells were treated with 60 µM MA and 10 nM TPT for 48 h (CI = 0,751; DRI = 10,871). CONCLUSION: This study, for the first time, furnishes compelling evidence that MA and TPT synergistically reduce cellular proliferation and induce apoptosis in SCLC cells. Combinations of these drugs holds promise as a potential therapeutic strategy to improve efficacy and reduce the side effects associated with TPT.

Downregulated GPD1 and MAGL protein levels as potential biomarkers for the metastasis of triple­negative breast tumors to axillary lymph nodes.

Glycerol-3-phosphate dehydrogenase (GPD1) and monoacylglycerol lipase (MAGL) levels are known to be significantly downregulated in both the tissue and serum samples of patients with triple-negative breast cancer (TNBC), compared with other BC subtypes and healthy controls. As such, the association between GPD1 and MAGL levels and lymph node metastasis was evaluated in the present study. Utilizing western blotting, lymph node protein extracts from metastasized BC subtypes were analyzed and a significant downregulation of GPD1 and MAGL protein expression levels in the lymph node metastases was demonstrated in the TNBC subtype, compared with healthy controls. This finding further highlighted the potential use of these two proteins in early BC onset and metastasis detection.

An experimental workflow for enrichment of low abundant proteins from human serum for the discovery of serum biomarkers.

Serum contains proteins that possess important information about diseases and their progression. Unfortunately, these proteins, which carry the information in the serum are in low abundance and are masked by other serum proteins that are in high abundance. Such masking prevents their identification and quantification. Therefore, removal of high abundance proteins is required to enrich, identify, and quantify the low abundance proteins. Immunodepletion methods are often used for this purpose, but there are limitations in their use because of off-target effects and high costs. Here we presented a robust, reproducible and cost-effective experimental workflow to remove immunoglobulins and albumin from serum with high efficiency. The workflow did not suffer from such limitations and enabled identification of 681 low abundance proteins that were otherwise undetectable in the serum. The identified low abundance proteins belonged to 21 different protein classes, namely the immunity-related proteins, modulators of protein-binding activity, and protein-modifying enzymes. They also played roles in various metabolic events, such as integrin signalling, inflammation-mediated signalling, and cadherin signalling. The presented workflow can be adapted to remove abundant proteins from other types of biological material and to provide considerable enrichment for low-abundance proteins.