Therapeutic implications of cancer stem cells in prostate cancer.

Prostate cancer, one of the most frequently occurring cancers in men, is a heterogeneous disease involving multiple cell types within tumors. This tumor heterogeneity at least partly results from genomic instability leading to sub-clonal cellular differentiation. The differentiated cell populations originate from a small subset of cells with tumor-initiating and stem-like properties. These cells, termed prostate cancer stem cells (PCSCs), play crucial roles in disease progression, drug resistance, and relapse. This review discusses the origin, hierarchy, and plasticity of PCSCs; methods for isolation and enrichment of PCSCs; and various cellular and metabolic signaling pathways involved in PCSC induction and maintenance, as well as therapeutic targeting.

Prosopis juliflora (Sw.) DC phytochemicals induce apoptosis and inhibit cell proliferation signaling pathways, EMT, migration, invasion, angiogenesis and stem cell markers in melanoma cell lines.

ETHNOPHARMACOLOGICAL RELEVANCE: Prosopis juliflora (Sw.), DC is a xerophytic plant species that extensively grow in Asia, Africa, Australia, and Brazil. From ancient time P. juliflora is being utilized in various folk remedies for example in wound healing, fever, inflammation, measles, excrescences, diarrhea and dysentery. Traditionally, gum, paste, and smoke obtained from the leaves and pods are applied for anticancer, antidiabetic, anti-inflammatory, and antimicrobial purposes. AIM OF THE STUDY: Our previous studies have demonstrated the promising potential of Prosopis Juliflora leaves methanol extract (PJLME) against breast cancer, and suggested its possible integration as a complementary medicine for the effective management of breast cancer. However, evidence against how PJLME mechanistically target the cancer proliferative pathways and other targets is poorly understood. The basic aim of the present study was to understand the anti-melanoma potential of PJLME against B16f10 cells with possible mechanisms of action. MATERIALS AND METHODS: MTT assay was used to determine cell viability. Wound and transwell migration assay was performed to check migration potential of cells after PJLME treatment, while clonogenic assay was carried out to understand its colony inhibition actvity. Flow cytometry was used to perform annexin V/PI assay (apoptosis assay), ROS assay, cell cycle analysis. In-vitro angiogenesis assay was performed to check formation of capillary like vascular structure after PJLME treatment. Apoptotic genes, signaling pathways markers, EMT markers and stem cell markers were determined by western blotting. In-vivo BALB/C mice xenograft model study was performed to check the effect of PJLME on in-vivo melanoma tumor growth. RESULTS: The experimental outcome of the present study has clearly demonstrated the inhibition of growth, migration, invasion, colony formation and apoptosis inducing potential of PJLME against mouse melanoma cancer cells. Treatment of B16F10 melanoma cells with PJLME resulted in arrest of cell cycle at G0/G1 phase. Annexin V-FITC/PI assay confirmed the apoptosis inducing potential of PJLME in B16F10 and A375 melanoma cells. Furthermore, Western blot experiments confirmed that the treatment of PJLME downregulates the expression of anti-apoptotic gene like Bcl2 and increase the expression profile of pro-apoptotic genes like Bax, Bad, and Bak in B16F10 melanoma cells. HUVEC (Human umbilical vein endothelial cells) tube formation assay clearly demonstrated the anti-angiogenic potential of PJLME. The study also revealed that PJLME has potential to inhibit the Akt and Erk signaling pathways which are participating in cancer cell proliferation, migration, invasion etc. The outcome of qRT-PCR and immunoblotting analysis clearly unveiled that PJLME treatment leads to downregulation of epithelial-mesenchymal transition (EMT) as well as stem cell markers. Finally, the in-vivo animal xenograft model study also revealed the anti-melanoma potential of PJLME by significantly inhibiting the B16F10 melanoma tumor growth in BALB/c mice model. The LC-ESI-MS/MS analysis of PJLME showed the presence of variety of bioactive molecules associated with anticancer effects. CONCLUSION: The outcome of the present investigation clearly demonstrated the anti-melanoma potential of PJLME against B16f10 melanoma cells. PJLME can be explored as an adjuvant or complementary therapy against melanoma cancer, however further studies are required to understand the clinical efficacy of PJLME. Nevertheless, it can be further explored as a promising resource for identification of novel anticancer candidate drug.

Chloroxylon swietenia (Roxb.) DC induces cell death and apoptosis by down-regulating the NF-κB pathway in MCF-7 breast cancer cells: In vitro and in vivo investigations.

BACKGROUND: Natural products with targeted bioactivity have gained major attention in the field of cancer research owing to emerging anti-cancer drug resistance and off target toxicities. Chloroxylon swietenia (Roxb.) DC is recognized as a folklore medicinal plant and has numerous therapeutic benefits in the folklore medicine system, however the anti-cancer potential of this plant and its mechanism of action is poorly understood. AIMS: The aim of the study was to investigate the anti-breast cancer efficacy of C. swietenia leaves methanol extract (CSLME) against MCF-7 hormone dependent human breast cancer cell line with possible mechanism of action. METHODS AND RESULTS: The anti-breast cancer activity of CSLME against MCF-7 cells was assessed by evaluating its efficacy toward cytotoxicity, cell migration, colony formation, DNA fragmentation, apoptosis, cytoskeleton, angiogenesis, cell cycle regulation, and animal toxicity. The preliminary screening of CSLME against MCF-7 cells revealed the cytotoxicity (IC50 20 µg/ml), inhibited cell migration, colony formation, and angiogenesis. It was observed that CSLME induces apoptosis by nuclear fragmentation and disruption of cytoskeleton by actin derangement. The results of Annexin V-FITC assay and cell cycle analysis by flow cytometry clearly pointed out the sizable fraction of apoptotic cells, and arrested the cells at G2/M phase of cell cycle. The results of the immunoblotting experiments showed that CSLME activates intrinsic pathway of apoptosis with down regulation of anti-apoptotic marker like Bcl2, up regulation of pro-apoptotic markers like Bax & Bad, along with successful cleavage of Caspase-9 and PARP-1. Further, western blot analysis revealed the possible down regulation of NF-κB pathway by CSLME, which may be responsible for anti-cancer activity in MCF-7 cells. In vivo animal model studies using NOD-SCID mice demonstrated impressive anti-tumor activity with significant reduction in tumor volume of MCF-7 tumor xenograft. Of note, in-vivo acute oral toxicity study as per Organization for Economic Cooperation and Development 423 revealed the nontoxic nature of CSLME. CONCLUSION: The in vitro and in vivo findings clearly outline the potential of CSLME as inhibitor of growth and proliferation of MCF-7 cells. Mechanistically, CSLME seems to activate intrinsic pathway of apoptosis, arrest cell cycle, target actin cytoskeleton, inhibit growth, colony formation, migration, and angiogenesis, with down regulation of NF-κB pathway leading to cell death.