Indian Journal of Experimental Biology Vol. 55, November 2017, pp. 747-755 Sodium butyrate induces p53 dependent and independent cell death in human brain tumor cells in primary culture in vitro Rohan Mitra 1,# , Vikas Vazhayil 2 , Indira Devi Bhagavatula 2 , Rohini Keshava 1 & Rajalakshmi Gope 1 * 1 Department of Human Genetics; 2 Department of Neurosurgery, NIMHANS, Bangalore 560 029, India. The anticancer effect of sodium butyrate (Na-Bu) has been demonstrated in many model systems. In this study, effect of Na-Bu on the survival of human brain tumor cells in primary culture was analyzed. A total of 20 glioblastoma multiforme (GBM), 15 astrocytomas, 15 meningiomas and 32 neurofibromatosis type 2 (NF2) tumor tissues were minced and cultured in primary cultures and the status of Fas, Bax, Bcl-2, p21 and p53 proteins were analyzed by western blotting after 48 h of Na-Bu exposure. Na-Bu treatment caused 75-80% cell death and it also increased the level of Fas protein in GBMs, astrocytomas, and meningiomas with mutant p53 but not with wild type p53. All the NF2 tumors had wild type p53, they had a trace level of Fas protein and Na-Bu exposure caused little change in Fas level. These data suggest that Na-Bu caused p53-dependent and p53-independent cell death in the brain tumors with wild type and mutant p53, respectively. All the Na- Bu treated samples had increased levels of pro-apoptotic Bax and anti-oncogenic p21 proteins, and decreased level of oncogenic, antiapoptotic Bcl-2 protein. These data indicate that the Na-Bu exposure caused cell death in these brain tumors due to apoptosis. Na-Bu could be developed as a therapeutic agent in the management of human brain tumors regardless of the p53 mutation status. Keywords: Anticancer, Apoptosis, Astrocytomas, Cancer, Glioblastoma multiforme (GBM), Meningiomas, Neurofibromatosis The primary human brain tumor accounts for less than 2% of all human cancers. However, it causes a disproportionate level of cancer related mortality and morbidity 1 . It is one of the devastating disorders where the survival rate from the time of diagnosis is very low and it has not shown any improvement despite intense research activity in this area since decades 2,3 . The human p53 gene is one of the important tumor suppressor genes and also commonly mutated gene in human brain tumors 4 . The mutant p53 protein has oncogenic function and the wild type has varied functions including cell cycle arrest and apoptosis 4,5 . Sodium butyrate (Na-Bu) is a naturally occurring, short chain fatty acid which induces cell death and differentiation of tumor cells in primary culture as well as in established tumor cell lines 6-10 . Na-Bu is reported to induce p53-independent, Fas-mediated apoptosis in human glioma cells and in human breast cancer cell line 11-13 . Na-Bu induced p53-mediated cell death in human vestibular schwannomas in primary culture in vitro 9 . In this study, we evaluated the effect of Na-Bu on the cell survival in a variety of human brain tumor samples in primary culture. The brain tumor samples with wild type and mutant p53 were included so as to evaluate if p53 mutational status affects the Na-Bu induced cell death. In addition, effect of Na-Bu on the levels of pro-apoptotic proteins p53, Fas, Bax and p21 and of anti-apoptotic and oncogenic protein Bcl-2 were also analysed. Materials and Methods Tumor samples This study was cleared by National Institute of Mental Health and Neuro Sciences (NIMHANS) Human Ethics Committee and it is in accordance with Indian Council of Medical Research (ICMR) ethical guidelines for biomedical research on human subjects which was formulated in the year 2000. Informed consents were obtained from the patients or parents/guardians (in case of minors) before collecting tumor tissue samples. Patients with only brain tumors were included in this study. Patients with other medical conditions or the ones taking prescription medications for other ailments were excluded from this study. Fresh tumor samples were collected from NIMHANS operation theatre and processed immediately. All the tumor samples used in this study are listed in Table 1. —————— *Correspondence: Phone: +91 80 2699 5125; Fax: +91 80 2656 4830 E-mail: rlgope@yahoo.com # Present add.: Novartis Healthcare Pvt. Ltd., Raheja Mind Space, Hyderabad-500 081 Supplementary data are available in respective journal web page at NOPR.