The Double-Edged Proteins in Cancer Proteomes and the Generation of Induced Tumor-Suppressing Cells (iTSCs)

Unveiling the Dichotomy of Urinary Proteins: Diagnostic Insights into Breast and Prostate Cancer and Their Roles

This review covers the diagnostic potential of urinary biomarkers, shedding light on their linkage to cancer progression. Urinary biomarkers offer non-invasive avenues for detecting cancers, potentially bypassing the invasiveness of biopsies. The investigation focuses primarily on breast and prostate cancers due to their prevalence among women and men, respectively. The intricate interplay of urinary proteins is explored, revealing a landscape where proteins exhibit context-dependent behaviors. The review highlights the potential impact of physical activity on urinary proteins, suggesting its influence on tumorigenic behaviors. Exercise-conditioned urine may emerge as a potential diagnostic biomarker source. Furthermore, treatment effects, notably after lumpectomy and prostatectomy, induce shifts in the urinary proteome, indicating therapeutic impacts rather than activating oncogenic signaling. The review suggests further investigations into the double-sided, context-dependent nature of urinary proteins, the potential role of post-translational modifications (PTM), and the integration of non-protein markers like mRNA and metabolites. It also discusses a linkage of urinary proteomes with secretomes from induced tumor-suppressing cells (iTSCs). Despite challenges like cancer heterogeneity and sample variability due to age, diet, and comorbidities, harnessing urinary proteins and proteoforms may hold promise for advancing our understanding of cancer progressions, as well as the diagnostic and therapeutic role of urinary proteins.

Exploring the Tumor-Suppressing Potential of PSCA in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with low survival rates. We explored an innovative therapeutic approach by leveraging prognostic oncogenic markers. Instead of inhibiting these marker genes, we harnessed their tumor-modifying potential in the extracellular domain. Surprisingly, many of the proteins highly expressed in PDAC, which is linked to poor survival, exhibited tumor-suppressing qualities in the extracellular environment. For instance, prostate stem cell antigens (PSCA), associated with reduced survival, acted as tumor suppressors when introduced extracellularly. We performed in vitro assays to assess the proliferation and migration and evaluated the tumor-modifying capacity of extracellular factors from peripheral blood mononuclear cells (PBMCs) in PDAC tissues. Molecular docking analysis, immunoprecipitation, Western blotting, and RNA interference were employed to study the regulatory mechanism. Extracellular PSCA recombinant protein notably curtailed the viability, motility, and transwell invasion of PDAC cells. Its anti-PDAC effects were partially mediated by Mesothelin (MSLN), another highly expressed tumor-associated antigen in PDAC. The anti-tumor effects of extracellular PSCA complemented those of chemotherapeutic agents like Irinotecan, 5-Fluorouracil, and Oxaliplatin. PSCA expression increased in a conditioned medium derived from PBMCs and T lymphocytes. This study unveils the paradoxical anti-PDAC potential of PSCA, hinting at the dual roles of oncoproteins like PSCA in PDAC suppression.

Anticancer peptides from induced tumor-suppressing cells for inhibiting osteosarcoma cells

Osteosarcoma (OS) is the most frequent primary bone cancer, which is mainly suffered by children and young adults. While the current surgical treatment combined with chemotherapy is effective for the early stage of OS, advanced OS preferentially metastasizes to the lung and is difficult to treat. Here, we examined the efficacy of ten anti-OS peptide candidates from a trypsin-digested conditioned medium that was derived from the secretome of induced tumor-suppressing cells (iTSCs). Using OS cell lines, the antitumor capabilities of the peptide candidates were evaluated by assaying the alterations in metabolic activities, proliferation, motility, and invasion of OS cells. Among ten candidates, peptide P05 (ADDGRPFPQVIK), a fragment of aldolase A (ALDOA), presented the most potent OS-suppressing capabilities. Its efficacy was additive with standard-of-care chemotherapeutic agents such as cisplatin and doxorubicin, and it downregulated oncoproteins such as epidermal growth factor receptor (EGFR), Snail, and Src in OS cells. Interestingly, P05 did not present inhibitory effects on non-OS skeletal cells such as mesenchymal stem cells and osteoblast cells. Collectively, this study demonstrated that iTSC-derived secretomes may provide a source for identifying anticancer peptides, and P05 may warrant further evaluations for the treatment of OS.