Objective: Autophagy is a form of physiological programmed cell death which is observable after hormonal withdrawal. In this study, the FM3A murine breast tumor cell line was treated with epirubicin alone and with medroxyprogesterone acetate (MPA) or tamoxifen, to determine if structural and kinetic signs of autophagy may also occur in an enhanced manner during epirubicin sensitization via hormonal agents. Methods: One-week soft agar colony growth, 96-hour values of plating and pulse thymidine labeling and electron microscopical examinations were performed following treatment with MPA and tamoxifen alone or with epirubicin. Results: Tamoxifen induced signs of autophagy, which was enhanced when it was combined with MPA. Epirubicin also induced autophagy of secretory granules, which coalesced to form an intracytoplasmic lumen. Combining MPA with epirubicin enhanced the formation of apoptotic blebs and chromatin fragmentation. When epirubicin was combined with tamoxifen, peculiar nuclear structures were formed. Conclusions: Hormonal agents may modulate anthracycline activity towards specific patterns in eliciting cell death, via autophagy and/or as yet unknown nucleolus-specific interactions.
Glioblastoma (GBM) develops resistance to the advances in chemotherapy leading to poor prognosis and life quality. Consequently, new treatment modalities are needed. Our aims were to investigate the effects of combined noscapine (NOS) and imatinib mesylate (IM) on human GBM in vitro and the role of midkine (MK) in this new combination treatment.
Rat C6 glioma is a chemo-resistant experimental brain tumor that is difficult to treat with various drug combinations. Previous studies suggested that imatinib mesylate (Gleevec) is effective in pre-clinical trials for glioblastoma. Also, chlorimipramine (Anafranil) is an anti-depressant drug in use in the clinic and shown to have anti-neoplastic activity. We hypothesized that treatment of resistant C6 glioma with combination of imatinib and chlorimipramine may potentiate cytotoxicity and reverse resistance. C6 glioma was examined both as monolayer and as spheroid cultures. Several experimental designs were examined all of which showed synergistic activity albeit at different time kinetics. Combination treatment resulted in inhibition of cell growth and enhanced cell death as determined by dye exclusion. Further, the combination treatment resulted in significant induction of apoptosis as determined by Annexin V-FITC and PI. Also, there was inhibition of DNA synthesis and cAMP. Altogether, these findings supported the anti-proliferative and cytotoxic effects of the combination treatment. Morphological studies were also performed using transmission and scanning electron microscopy. Significant synergistic apoptosis was detected by the combination treatment in both the monolayers and spheroid cultures. There was also a synergistic effect in autophagy by the combination. Several altered morphological features were noted by both the individual compound and enhanced by the combination treatment. The present findings support our hypothesis and demonstrate the potentiation of cytotoxicity by the combination of imatinib and chlorimipramine in C6 glioma. Further, the findings suggest the potential clinical application of the combination in the treatment of drug-resistant glioma.
Delayed wound healing in elderly males is a complex process in which the factors responsible are not fully understood. This study investigated the hormonal, oxidative and angiogenic factors affecting wound healing in aged rats. Two groups consisting of eight healthy male Wistar Albino rats [young (30 ± 7 days) and aged (360 ± 30 days)], and a cutaneous incision wound healing model were used. Scar tissue samples from wounds on the 7th, 14th and 21st days of healing were evaluated for hydroxyproline and vascular endothelial growth factor content. Macrophage, lymphocyte, fibroblast and polymorphonuclear cell infiltration; collagen formation and vascularization were assessed by light and electron microscopy. The free oxygen radical content of the wounds was measured by a chemiluminescence method. Blood sample analysis showed that the hydroxyproline and total testosterone levels were significantly higher, and the oxygen radical content was significantly lower in young rats. Histopathological, immunohistochemical and ultrastructural evaluations revealed higher amounts of fibroblasts and collagen fibers, and more vascularization in young rats. These results are indicative of the delayed wound healing in aged rats. A combination of multiple factors including hormonal regulation, free oxygen radicals and impaired angiogenesis appears to be the cause of delayed cutaneous healing.
Midkine (MDK) is a heparin-binding growth factor implicated in the pathogenesis of various diseases, including cancer, chronic inflammation, and multidrug resistance (MDR). While its expression is minimal in adult tissues, it becomes markedly elevated during embryogenesis and in response to injury, infection, or hypoxia. MDK modulates inflammatory responses by recruiting immune cells and enhancing proinflammatory cytokine production. In oncogenesis, it promotes tumor proliferation, angiogenesis, epithelial-to-mesenchymal transition (EMT), and therapeutic resistance. Elevated MDK levels are frequently associated with aggressive tumor behavior and poor clinical outcomes. This review synthesizes current knowledge on MDK’s expression profiles, molecular mechanisms, and functional roles across pathological conditions. It also discusses MDK’s emerging value as a diagnostic and prognostic biomarker, and highlights recent advances in therapeutic strategies including small molecule inhibitors, RNA-based approaches, and receptor-blocking peptides. Overall, MDK represents a promising target for future personalized therapies, although further preclinical and clinical validation is warranted to confirm its translational potential.