Steroidal alkaloid solanidine impedes hypoxia-driven ATM phosphorylation to switch on anti-angiogenesis in lung adenocarcinoma.

PURPOSE: The declined oxygen tension in the cancer cell leads to the hypoxic adaptive response and favors establishment of tumor micro environment [TEM]. The complex TME consists of interwoven hypoxic HIF-1α and DNA damage repair ATM signaling. The ATM/HIF-1α phosphorylation switch on angiogenesis and abort apoptosis. Targeting this signaling nexus would be a novel therapeutic strategy for the treatment of cancer. BACKGROUND: Steroidal alkaloid solanidine is known for varied pharmacological role but with less molecular evidences. Our earlier findings on solanidine proven its anti-neoplastic activity by inducing apoptosis in lung cancer. In continued research, efforts have been made to establish the underlying molecular signaling in induction of DNA damage in prevailing hypoxic TME. METHODS: The solanidine induced DNA damage was assessed trough alkali COMET assay; signaling nexus and gene expression profile analysis through IB, qRT-PCR, Gelatin Zymography, IHC, IF and ELISA. Pathophysiological modulations assessed through tube formation, migration, invasion assays. Anti-angiogenic studies through CAM, rat aorta, matrigel assays and corneal neovascularization assay. Anti-tumor activity through in-vivo DLA ascites tumor model and LLC model. RESULTS: The results postulates, inhibition of hypoxia driven DDR proteins pATMser1981/pHIF-1αser696 by solanidine induces anti-angiogenesis. Systematic study of both non-tumorigenic and tumorigenic models in-vitro as well as in-vivo experimental system revealed the angio-regression mediated anticancer effect in lung cancer. These effects are due to the impeded expression of angiogenic mediators such as VEGF, MMP2&9 and inflammatory cytokines IL6 and TNFα to induce pathophysiological changes CONCLUSION: The study establishes new role of solanidine by targeting ATM/HIF-1α signaling to induce anti-angiogenesis for the first time. The study highlights the potentiality of plant based phytomedicine solanidine which can targets the multiple hallmarks of cancer by targeting interwoven signaling crosstalk. Such an approach through solanidine necessary to counteract heterogeneous complexity of cancer which could be nearly translated into drug.

Matrix-Metalloproteinase Inhibitory Study of Novel Tetrahydroisoquinoline-4-carboxylates: Design, Synthesis, and Molecular Docking Studies.

The design, molecular docking, synthesis and structure-activity relationship (SAR) of a series of novel methyl 1-oxo-2-(propan-2-yl)-3-(pyridin-3-yl)-1,2,3,4-tetrahydroisoquinoline-4-carboxylates, were investigated for antiproliferative and cytotoxic studies by screening against cancer cell lines of different origin by MTT, LDH and Trypan Blue Assay. Irrespective of cell lines, among the synthesized nonpeptido-mimetic analogs 5a-e, 5c has executed potent bio-potency with IC50 value of 7.00 to 7.21 µM, which further expressed in-vivo anti-tumor activity against murine T-cell lymphoma cell lines (Daltons Lymphoma-DLA) by regressing tumor growth. The formation of neovessels from the vasculogenesis was diminished reflecting the antitumor activity. The neovessel formation is directly relied on expression of matrix meteloproteases (MMP's) level which was drastically reduced by 5c treatment as evaluated by immonoblot assays. This is further supported by in-silico ADMET studies performed by ACD I-Lab 2.0 were in agreement with Lipinski rule of five. Reporting results were assessed as a positive parameter for further validation of the compound for therapeutic potential of cancer by 5c for preclinical studies in near future.