Chronic unpredictable stress (CUS) enhances the carcinogenic potential of 7,12-dimethylbenz(a)anthracene (DMBA) and accelerates the onset of tumor development in Swiss albino mice.
Social stressors evolving from individual and population interactions produce stress reactions in many organisms (including humans), influencing homeostasis, altering the activity of the immunological system, and thus leading to various pathological states including cancer and their progression. The present study sought to validate the effectiveness of chronic unpredictable stress (CUS) in cancer promotion and to assess oxidative stress outcomes in terms of various in vivo biochemical parameters, oxidative stress markers, DNA damage, and the development of skin tumors in Swiss albino mice. Animals were randomized into different groups based on their exposure to CUS alone, 7,12-dimethylbenz(a)anthracene (DMBA) alone (topical), and DMBA-12-O-tetradecanoylphorbol-13-acetate (TPA) (topical) and exposure to CUS prior to DMBA or DMBA-TPA treatments and sacrificed after 16 weeks of treatment. Prior exposure to CUS significantly increased the pro-oxidant effect of carcinogen, depicted by compromised levels of antioxidants in the circulation and skin, accompanied by enhanced lipid peroxidation, plasma corticosterone, and marker enzymes as compared to DMBA-alone or DMBA-TPA treatments. DNA damage results corroborated the above biochemical outcomes. Also, the development of skin tumors (in terms of their incidence, tumor yield, and tumor burden) in mice in the presence and absence of stress further strongly supported our above biochemical measurements. CUS may work as a promoter of carcinogenesis by enhancing the pro-oxidant potential of carcinogens. Further studies may be aimed at the development of interventions for disease prevention by identifying the relations between psychological factors and DNA damage.
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University (AMU), Aligarh, Uttar Pradesh (U.P.), India. nsuhail123@gmail.com.|Department of Biochemistry, Faculty of Medicine and Applied Medical Sciences, Northern Borders University, Arar, Kingdom of Saudi Arabia. nsuhail123@gmail.com.
Nida
N
Suhail
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University (AMU), Aligarh, Uttar Pradesh (U.P.), India.
Nayeem
N
Bilal
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University (AMU), Aligarh, Uttar Pradesh (U.P.), India.|Department of Surgery, Loyola University Medical Center, Maywood, Illinois, USA.
Shirin
S
Hasan
Amity Institute of Biotechnology (AIB), Amity University Uttar Pradesh (AUUP), Lucknow, Uttar Pradesh (U.P.), 226010, India.
Ausaf
A
Ahmad
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University (AMU), Aligarh, Uttar Pradesh (U.P.), India.|King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia.
Ghulam Md
GM
Ashraf
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University (AMU), Aligarh, Uttar Pradesh (U.P.), India.|College of Medical Rehabilitation, Qassim University, Qassim, P.O. Box 2100, Buraydah, 51451, Saudi Arabia.
Naheed
N
Banu
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000633:toxicity*; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D003080:Cold Temperature; D004249:DNA Damage / Q000187:drug effects; D008297:Male; D051379:Mice; D018384:Oxidative Stress / Q000502:physiology; D017382:Reactive Oxygen Species / Q000378:metabolism; D012149:Restraint, Physical / Q000009:adverse effects; D012878:Skin Neoplasms / Q000139:chemically induced / Q000378:metabolism; D013315:Stress, Psychological / Q000503:physiopathology*
D002273:Carcinogens; D017382:Reactive Oxygen Species; D015127:9,10-Dimethyl-1,2-benzanthracene
7,12-Dimethylbenz(a)anthracene; Antioxidants; Chronic unpredictable stress; Corticosterone; DNA damage; Skin tumors