en ژنتیک میکروبی Microbial Genetics مقاله پژوهشی Original Research Article <p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Background and Aim:</span></span></span></b><span style="color:black">&nbsp;</span></span></span><span style="color:#000000;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><span style="line-height:150%"><span style="line-height:150%"><span new="" roman="" times="">Breast cancer is one of the leading causes of cancer-related deaths among women worldwide. The resistance of advanced tumors to conventional treatments highlights the need for alternative therapies. Apoptosis, regulated by key proteins like BAX (pro-apoptotic) and BCL-2 (anti-apoptotic), plays a crucial role in controlling cancer cell proliferation. This study aimed to investigate the effects of a halotolerant <i>Bacillus (B.) licheniformis</i> extract, isolated from Hoz-e Sultan Lake in Qom Province, on the expression of <i>BAX</i> and <i>BCL-2</i> genes in MCF-7 breast cancer cell line.</span></span></span></span></span></span><br> <span style="font-size:16px;"><span style="font-family:Times New Roman;"><b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Materials and Methods:</span></span></span></b><span style="color:black"> </span></span></span><span style="color:#000000;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><span style="line-height:150%"><span style="line-height:150%"><span new="" roman="" times="">MCF-7 cells were treated with various concentrations of the bacterial extract and cell viability was assessed using MTT assay. Staurosporine was used as positive control</span></span><span dir="RTL" lang="AR-SA"><span style="line-height:150%"><span new="" roman="" times="">.</span></span></span><span style="line-height:150%"><span new="" roman="" times=""> RNA extraction, cDNA synthesis, and Real-Time PCR were performed to evaluate target genes expression levels. Statistical analysis was conducted using an independent t-test and P-values less than 0.05 were considered significant.</span></span></span></span></span></span><span style="font-size:16px;"><span style="font-family:Times New Roman;"><span style="color:black"> </span><br> <b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Results:</span></span></span></b><span style="color:black"> </span></span></span><span style="color:#000000;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><span style="line-height:150%"><span style="line-height:150%"><span new="" roman="" times="">The extract significantly increased <i>BAX</i> expression (<i>P</i><0.05) at 24, 48, and 72 hr, while <i>BCL-2</i> expression initially decreased but showed a slight increase at 48 hr. The IC₅₀ values decreased over time, indicating time-dependent cytotoxicity.</span></span></span></span></span></span><br> <span style="font-size:16px;"><span style="font-family:Times New Roman;"><b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Conclusion:</span></span></span></b><span style="color:black">&nbsp;</span></span></span><span style="color:#000000;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><span style="line-height:150%"><span style="line-height:150%"><span new="" roman="" times="">The halotolerant <i>B. licheniformis</i> extract induced apoptosis in MCF-7 cells through BAX/BCL-2 pathway modulation, suggesting its potential as an alternative therapeutic source. Further studies are needed to identify active compounds and validate efficacy <i>in vivo</i>.</span></span></span></span></span></span></p> Apoptosis, Bacillus licheniformis, BAX, BCL-2, Breast Cancer, MCF-7 5 5 http://ijmm.ir/browse.php?a_code=A-10-2852-1&slc_lang=en&sid=1 Mahdiyeh Khoshandam mahdiyekhoshandam@gmail.com 100319475328460033873 100319475328460033873 No Department of Genetics, Islamic Azad University, Qom, Iran Mehrdad Memarian mehr.memarian@yahoo.com 100319475328460033874 100319475328460033874 No Department of Microbiology, Islamic Azad University, Qom Branch, Qom, Iran Naser Kalhor naserkalhor@gmail.com 100319475328460033875 100319475328460033875 No Department of Cell Biology and Regenerative Medicine, Academic Center for Education, Culture and Research, Qom Branch, Qom, Iran Mohadeseh Khoshandam mohi_khosh70@yahoo.com 100319475328460033876 100319475328460033876 No National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran Hossein Soltaninejad hosoltaninejad@gmail.com 100319475328460033877 100319475328460033877 Yes Department of Stem Cells Technology and Tissue Regeneration, Faculty of Interdisciplinary Science and Technologies, Tarbiat Modares University, Tehran, Iran Mohammad Taghi Hedayati Goudarzi drmohammadhedayati@yahoo.com 100319475328460033878 100319475328460033878 No Department of Cardiology, School of Medicine, Babol University of Medical Sciences, Babol, Iran