Immunomodulatory glc/man-directed Dolichos lablab lectin (DLL) evokes anti-tumour response in vivo by counteracting angiogenic gene expressions.

Neovascularization and jeopardized immunity has been critically emphasized for the establishment of malignant progression. Lectins are the diverse class of carbohydrate interacting proteins, having great potential as immunopotentiating and anti-cancer agents. The present investigation sought to demonstrate the anti-proliferative activity of Dolichos lablab lectin (DLL) encompassing immunomodulatory attributes. DLL specific to glucose and mannose carbohydrate moieties has been purified to homogeneity from the common dietary legume D. lablab. Results elucidated that DLL agglutinated blood cells non-specifically and displayed striking mitogenicity to human and murine lymphocytes in vitro with interleukin (IL)-2 production. The DLL-conditioned medium exerted cytotoxicity towards malignant cells and neoangiogenesis in vitro. Similarly, in-vivo anti-tumour investigation of DLL elucidated the regressed proliferation of ascitic and solid tumour cells, which was paralleled with blockade of tumour neovasculature. DLL-treated mice showed an up-regulated immunoregulatory cytokine IL-2 in contrast to severely declined levels in control mice. Mechanistic validation revealed that DLL has abrogated the microvessel formation by weakening the proangiogenic signals, specifically nuclear factor kappa B (NF-κB), hypoxia inducible factor 1α (HIF-1 α), matrix metalloproteinase (MMP)-2 and 9 and vascular endothelial growth factor (VEGF) in malignant cells leading to tumour regression. In summary, it is evident that the dietary lectin DLL potentially dampens the malignant establishment by mitigating neoangiogenesis and immune shutdown. For the first time, to our knowledge, this study illustrates the critical role of DLL as an immunostimulatory and anti-angiogenic molecule in cancer therapeutics.

DAO-9 (2,5-di(4-aryloylaryloxymethyl)-1,3,4-oxadiazole) exhibits p53 induced apoptogenesis through caspase-3 mediated endonuclease activity in murine carcinoma.

One of the main strategies to inhibit the tumor growth is to promote the biochemical events leading to DNA degradation, which would eventually culminate in apoptosis. We have earlier reported that the 2,5-di(4-aryloylaryloxymethyl)-1,3,4-oxadiazole(DAO-9) possessed anti-cancer activity. To address the exact molecular mechanism underlying anti-cancer property, present study focused on evaluating the anti-tumor effect of the DAO-9 on murine ascites carcinoma cells using various in vivo and in vitro assays. The in vivo assays implicated a strong regression in tumor growth of ascites carcinoma after treatment which is due to apoptogenic efficacy as assessed through structural morphology of EAC cells by Giemsa, Acridine orange, Annexin V staining and FACS analysis. Nucleosomal DNA fragmentation induced by DAO-9 is due to activation of caspase-3 mediated DNAse as verified by endonuclease assays and immunoblot analysis. The caspase-3 activation mechanism is by induction of intrinsic cascade signaling molecules, such as p53, Bax, Bad and cytochrome c (cyt c) expression as verified by western blot. The results concluded that the tumor inhibiting activity of DAO-9 is due to activation of the apoptotic signaling cascade, which could be translated into targeted anti-cancer drug in the near future.