Ali Hussein Ad'hiah
Layla Mohammed Hassan Al-Ameri
Amel Mustfa Maki
Qiuyu Wang
Mayada Hameed ALQaisi

Abstract Introduction: Heat shock proteins (HSPs) are molecular chaperones involved in protein folding, stability and turnover, and due to their role in cancer progression, the effect of low power laser irradiation (LPLI) on the expression of HSP۷۰ and HSP۹۰ in Jurkat E۶.۱ T-lymphocyte leukemia (JELT) cell line was investigated in vitro.Methods: JETL cells were irradiated with LPLI at ۶۳۵nm and ۷۸۰m wavelengths (energy density ۹.۱۷۴ J/cm۲), and assessed for the expression of HSP۷۰ and HSP۹۰ by flow cytometry after ۲۴, ۴۸ and ۷۲ incubation time periods (ITPs).Results: At ۲۴ hours ITP post-irradiation, control cultures showed that ۱۰.۷% of cells expressed HSP۷۰, while LPLI cultures at ۶۳۵nm and ۷۸۰nm manifested a higher expression (۳۲.۱and ۲۱.۳%, respectively), and the difference was significant (P ≤ ۰.۰۵). However, at ۴۸ hours ITP, the three means were decreased but approximated (۵.۶, ۴.۹ and ۶.۲%, respectively), while at ۷۲ hours ITP, they were markedly increased (۴۵.۲, ۷۶.۵ and ۶۶.۷%, respectively). In contrast, HSP۹۰ responded differently to LPLI. At ۲۴ hours ITP, control cultures and ۷۸۰nm cultures showed a similar expression (۵۵.۹ and ۵۵.۹%, respectively), but both means were significantly higher than that of ۶۳۵nm cultures (۲۴.۰%). No such difference was observed at ۴۸ hours ITP, and at ۷۲ hours ITP, control cultures and ۶۳۵nm cultures shared approximated means (۳۱.۷ and ۳۵.۶%, respectively); but both means were significantly higher than the observed mean in ۷۸۰nm cultures (۱۵.۲%).Conclusion: The results highlighted that HSP۷۰ and HSP۹۰ expression responded differently to LPLI in JETL cells; an observation that may pave the way for further investigations in malignant cells. Keywords: laser Irradiation low-Power Jurkat cell leukemia cell Heat shock proteins