Rapamycin inhibits proliferation and induces autophagy in human neuroblastoma cells

Abstract

Objective To investigate the effect of Rapamycin on proliferation and autophagy in human neuroblastoma (NB) cell lines and to elucidate the possible mechanism. Methods NB cells were treated with different concentrations of Rapamycin. Cell counting kit-8 (CCK-8) was used to measure proliferation, and flow cytometry (FCM) was used to analyze the cell cycle. EM was used to observe cell morphological changes. Western blotting (WB) was performed to detect the expression of Beclin-1, LC3-I/II, P62, mammalian target of Rapamycin (mTOR), and p-mTOR. Results Rapamycin inhibited the spread of NB cells in a dose- and time-dependent manner and arrested the cell cycle at the G0/G1 phase. EM showed autophagosomes in NB cells treated with Rapamycin. The WB results showed that the expression levels of Beclin-1 and LC3-II/LC3-I were significantly elevated in NB cells treated with Rapamycin, while the expression levels of P62, mTOR, and p-mTOR proteins were significantly reduced compared with the control cells (P<0.05). Conclusion Rapamycin inhibits cell proliferation and induces autophagy in human NB cell lines. The mechanism may be related to suppression of the mTOR signaling pathway.

Effect of autophagy induction and cathepsin B inhibition on developmental competence of poor quality bovine oocytes

“…Recent research revealed induction of autophagy by cystatin c plays a protective role in murine primary cortical neurons and neuronal cell lines under conditions of neuronal challenge by inducing autophagy via the inhibition of mammalian target of rapamycin (mTOR) [38] and mTOR forms the catalytic core of at least two functionally distinct complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) [8]. In the present study, we induced autophagy using rapamycin, a special prophylactic for mTOR that inhibits mTOR activity [39] thereby inducing autophagy [40]. Indeed, rapamycin preferentially inhibits mTORC1 by interfering with complex assembly and thereby suppresses mTORC1 downstream targets, including ribosomal S6 protein kinase 1 (S6K1), eukaryotic initiation factor 4E-binding protein 1 (4EBP1), and UNC-51-like kinases (ULKs).…”

Autophagy Takes Center Stage as a Possible Cancer Hallmark

“…For example, rapamycin is a selective inhibitor of mTORC1 and causes activation of autophagy (209). In several studies, rapamycin has been demonstrated to suppress cancer proliferation and induce autophagic cell death in different cancer models, such as neuroblastoma, osteosarcoma, and sarcoma (210)(211)(212). Rapamycin analogs (rapalogs), such as temsirolimus and everolimus, also inhibit the mTOR pathway in renal cancer and breast cancer, among others (213,214).…”

Role of Autophagy in Cancer Cell Response to Nucleolar and Endoplasmic Reticulum Stress

“…Furthermore, the induction of autophagy associated to mTOR inhibition may mediate some effects on tumor development [ 95 ]. Rapamycin has been shown to inhibit proliferation and induce autophagic cell death in murine sarcoma, neuroblastoma, lung cancer and osteosarcoma [ 96 , 97 , 98 , 99 ]. In addition, Everolimus (or RAD001), a rapamycin analogue, was approved by FDA for use in different types of tumors, including advanced renal cell carcinoma, advanced pancreatic neuroendocrine tumors, renal angiomyolipoma and HER2-negative breast cancer.…”