Biology subjects

Abdul Rahman, S. F.

Publications and source records attributed to Abdul Rahman, S. F..

3 recordsLinked to original sources

bioRxiv2021

Dual inhibition of anti-apoptotic proteins BCL-XL and MCL-1 enhances cytotoxicity of Nasopharyngeal carcinoma cells.

One of the many strategies that cancer cells use to evade cell death is through upregulation of the BCL-2 anti-apoptotic proteins. Hence, these proteins have become attractive therapeutic targets. Given that different cell population rely on different anti-apoptotic proteins for survival, it is crucial to determine which proteins are important for NPC survival. Here we determined the survival requirements for the NPC cells using combination of CRISPR/Cas9 technique and pharmacological approaches. A human apoptosis RT2 Profiler PCR Array was first employed to profile the anti-apoptotic gene expressions in NPC cell lines HK-1 and C666-1. The HK-1 cells expressed all the anti-apoptotic genes (MCL-1, BFL-1, BCL-2, BCL-XL, and BCL-w). Similarly, the C666-1 cells expressed all the anti-apoptotic proteins except BFL-1 (undetectable level). Notably, both cell lines highly expressed MCL-1. Deletion of MCL-1 sensitized cells to A-1331852 suggesting that MCL-1 and BCL-XL may be important for NPC cell survival. Co-inhibition of MCL-1 and BCL-2 with MCL-1 selective inhibitor S63845 and BCL-2 selective inhibitor ABT-199 inhibited NPC cell proliferation but the effect on cell viability was more profound with co-inhibition of MCL-1 and BCL-XL with S63845 and A-1331852, implying that MCL-1 and BCL-XL are crucial for NPC cell survival. Furthermore, co-inhibition of MCL-1 and BCL-XL inhibited the growth and invasion of NPC spheroids. Deletion of BFL-1 sensitized cells to A-1331852 suggesting that BFL-1 may play a role in NPC cell survival. Taken together co-inhibition of BCL-XL and MCL-1/BFL-1 could be potential treatment strategies for NPC.

cancer biology↗

bioRxiv2020

Mitragyna alkaloids derived from the medicinal plant Mitragyna speciosa Korth. and cisplatin synergistically inhibit cell proliferation of Nasopharyngeal Carcinoma (NPC) cell lines

Ethnopharmacological relevanceMitragyna speciosa (Korth.) or kratom is a medicinal plant indigenous to Southeast Asia. The leaves of M. speciosa is used as a medication in pain management including cancer related pain, in a similar way as opioids and cannabis. Despite its well-known analgesic effect, there is a scarce of information on the cancer-suppressing potential of M. speciosa and its active constituents. Aim of the studyTo assess the potential applicability of M. speciosa alkaloids (mitragynine, speciociliatine or paynantheine) as chemosensitizers for cisplatin in Nasopharyngeal carcinoma (NPC) cell lines. Materials and MethodsThe cytotoxic effects of the extracts, fractions and compounds were determined by conducting in vitro cytotoxicity assays. Based on the cytotoxic screening, the alkaloid extract of M. speciosa exhibited potent inhibitory effect on the NPC cell line HK-1, and therefore, was chosen for further fractionation and purification. NPC cell lines HK-1 and C666-1 were treated with combinations of cisplatin and M. speciosa alkaloids in 2D monolayer culture. The effect of the drug combination on cell migration was tested using in vitro wound healing and spheroid invasion assays. ResultsIn our bioassay guided isolation, both methanolic and alkaloid extracts showed mild to moderate cytotoxic effect against the HK-1 cell line. Both NPC cell lines were insensitive to single agent and combination treatments of the M. speciosa alkaloids. However, mitragynine and speciociliatine sensitised the HK-1 and C666-1 to cisplatin ~4- and >5-fold, respectively in 2D monolayer culture. The combination of mitragynine and cisplatin also significantly inhibited cell migration of the NPC cell lines. Similarly, combination of mitragynine and cisplatin inhibited growth and invasion of HK-1 spheroids in a dose-dependent manner. Moreover, the spheroids did not rapidly develop resistance to the drug combinations at high concentrations over 10 days. ConclusionCollectively, data shows that both mitragynine and speciociliatine could be potential chemosensitizers for cisplatin. Further extensive drug mechanistic studies and investigations in animal models are necessary to delineate the applicability of M. speciosa alkaloids for NPC therapy.

cancer biology↗

bioRxiv2019

Co-inhibition of BCL-XL and MCL-1 with BCL-2 selective inhibitors A1331852 and S63845 enhances cytotoxicity of cervical cancer cell lines

A combination of the BCL-2 inhibitors ABT-263 and A-1210477 inhibited cell proliferation in the HeLa, C33A, SiHa and CaSki human cervical cancer cell lines. Drug sensitivity was initially tested using 2-dimensional (2D) cell culture models. As ABT-263 binds to both BCL-2 and BCL-XL at high affinity, it was unclear whether the synergism of the drug combination was driven either by singly inhibiting BCL-2 or BCL-XL, or inhibition of both. Therefore, we used the BCL-2 selective inhibitor ABT-199 and the BCL-XL selective inhibitor A1331852 to resolved the individual antitumor activities of ABT-263 into BCL-2 and BCL-XL dependent mechanisms. A-1210477 was substituted with the orally bioavailable S63845. The SiHa, C33A and CaSki cell lines were resistant to single agent treatment of all three drugs, suggesting that none of these anti-apoptotic proteins singly mediate survival of the cells. HeLa cells were resistant to single agent treatment of ABT-199 and A1331852 but were sensitive to S63845 indicating that they depend on MCL-1 for survival. Co-inhibition of BCL-XL and MCL-1 with A1331852 and S63845 significantly inhibited cell proliferation of all four cell lines. Similar data were obtained with 3-dimensional spheroid cell culture models generated from two cervical cancer cell lines in vitro. Treatment with a combination of A1331852 and S63845 resulted in inhibition of growth and invasion of the 3D spheroids. Co-inhibition of BCL-2 and MCL-1 with ABT-199 and S63845, also inhibited cell proliferation of all cancer cell lines, except SiHa. However, the effect of the combination was not as pronounced as combination of A1331852 and S63845. Collectively, our data demonstrate that the combination of MCL-1-selective inhibitors with either selective inhibitors of either BCL-XL or BCL-2 may be potentially useful as treatment strategies for the management of cervical cancer.

cancer biology↗