microtubule disrupting agentmediated inhibition of cancer cell growth is associated with blockade of autophagic flux and simultaneous induction of apoptosis objectives given that autophagy inhibition is a feasible way to enhance sensitivity of cancer cells towards chemotherapeutic agents identifying potent autophagy inhibitor has obvious clinical relevance here we investigated ability of tn16 a microtubule disrupting agent on modulation of autophagic flux and its significance in promoting in vitro and in vivo cancer cell deathmaterials and methods the effect of tn16 on cancer cell proliferation cell division autophagic process and apoptotic signalling was assessed by various biochemical western blot and srb assay morphological tem sem confocal microscopy and flowcytometric assays in vivo antitumour efficacy of tn16 was investigated in syngeneic mouse model of breast cancerresults tn16 inhibited cancer cell proliferation by impairing latestage autophagy and induction of apoptosis inhibition of autophagic flux was demonstrated by accumulation of autophagyspecific substrate p62 and lack of additional lc3ii turnover in the presence of lysosomotropic agent the effect was validated by confocal micrographs showing diminished autophagosomelysosome fusion further studies revealed that tn16mediated inhibition of autophagic flux promotes apoptotic cell death consistent with in vitro data results of our in vivo study revealed that tn16mediated tumour growth suppression is associated with blockade of autophagic flux and enhanced apoptosisconclusions our data signify that tn16 is a potent autophagy flux inhibitor and might be suitable for pre clinical use as standard inhibitor of autophagy with anticancer activity