Apoptosis-coupled senescence causes cancer cell senotherapy

Abstract

Although new generations of anti-cancer modalities have been accumulated involving immuno-oncology cancers remain prevailing. This implies the current understanding of cancer cell biology is far from satisfactory. Curation of cancers is extremely rare. We hypothesized what could be the easiest Achilles Hill of cancer cells such that simple administration can jab cancer cells to be knocked out. Of conspicuous differences between cancer cells and normal cells, for example, metabolism, hypoxia, anaerobic glycolysis, uncontrolled cell proliferation, etc. exist. What could be the easiest and the most reliable anti-cancer modalities? We discovered one was cancer cell senescence (CCS) because cancer cells are the most presenescent (old) cells. We utilized a synthetic polyphenol designated as ONG41008. ONG41008 was able to induce massive senescence of pathologic myofibroblasts (pMFBs) and a vast majority of representative human cancer cells as well as a line of primary NSCLCs. All these cells turned out to be senescence-associated beta-galactosidase (SAbGAL) positive to different degrees, which does not mean real senescence is occurring in these cells. ONG41008 did not harm normal cells and elicited massive senescence in pMFBs without apoptosis. However, ONG41008 caused massive senescence as well as apoptosis in cancer cells. In other words, ONG41008 was capable of sensing intracellular molecular environments between normal cells, cancer cells, and pMFBs. This molecular recognition capability prompted us to explore how ONG4008 behaved on A549 (a human lung adenocarcinoma), PANC1(malignant human ductal adenocarcinoma), and mdr+PC3 (multidrug-resistant human prostate cancer). TP53, p21, and p16 were induced and/or nuclear relocated, suggesting that ONG41008 was recognized by these cells. ONG41008 drove A549 and PANC1 at G2/M phase arrest during 48 hrs, resulting in massive mitotic collapse. All cells died. Moreover, the cisplatin-resistant mdr+PC3 was also eliminated by ONG41008. An array of common components of apoptosis were activated, and especially, induction of Mcl1 was especially notable. These senolytics features were reported to oncogene-induced-senescence (OIS), in which the expression of over two activated oncogenes in the embryonic fibroblasts caused massive senescence and cell death as well. And the signature expression of Mcl1, an anti-apoptotic protein (a long form), was notable but two kinds of short forms are pro-apoptotic proteins. OIS was conducted in vitro cell culture models and whether or not the presence of OIS counterpart in vivo remains to be delineated. Taken together, we discovered a synthetic polyphenol referred to as ONG41008 was both senogenic and senolytic and its senescent impacts may make the cell cycles of the ONG41008-treated cancer cells immensely arrested at the G2/M phase, leading to mitotic slippage and cell death. This interesting observation may be able to create an idealistic anti-cancer modality, specifically killing cancer cells, but normal cells remain unharmed.