Study Of The Effect Of 15-Lox-1 On MCF-7 Cells Balancing Between The Tumor Promoting Factor Of AKT And The Tumor Suppressor Activity Of PPAR?

Breast cancer is a malignancy occurred in the breast tissue,which is one of the most common tumor threating women's healthy.Its pathogenesis is fast and it is easy to metastasize leading to some complication.Breast cancer cells can transfer to pleura,lung,bone,liver,brain and so on,following blood or lymphatic channel.So,the main cause leading death of the patients is tumor metastasis.At the same time,preventing tumor metastasis has become a hot topic of cancer precaution and therapy.There are about 200 thousands new patients with breast cancer in China every year.The morbidity and mortality goes up every year.Although we can cure breast carcinoma in situ efficiently by operative treatment,chemotherapy,radiotherapy,endocrine and molecular targeted therapy,the treatment effect is not very well and the prognosis do not come to an ideal condition for these patients whose cancer have metastasized.Furture study of moleculor mechanism about the development of breast cancer is the key to treatment strategies.The research of this subject has advanced the process of tumor gene therapy to a certain extent.AKT has been found for more than a decade.In recent years,attention has increased year by year.It regulating cell cycle,metabolism,survival,transcription and other biology Process.It is closely related to the occurrence and development of cancer,diabetes and other diseases.PPARs belong to the nuclear receptor superfamily members,including PPAR?,PPAR? and PPAR?.At present,study shows that PPAR? is activated by its corresponding ligand,banding with the target gene promoter on the PPRE,and then regulate the expression of target gene,finally regulate cell physiological function.A sea of experimental results show PPAR? is an important target of prevention and treatment of chronic diseases,such as diabetes,metabolic syndrome and atherosclerosis.In recent years,reseachers found that different organs of tumor cells express PPAR? prevalently,suggesting that PPAR? may be closely related to the occurrence and development of tumor.A number of studies in vivo and in vivo have confirmed that many PPAR? ligands such as TZDs have anti-tumor effects such as inhibiting tumor cell proliferation,invasion and metastasis,inducting tumor cell apoptosis,and anti-tumor angiogenesis.PPAR? has potential clinical value in the prevention and treatment of cancer,especially in the inhibition of tumor metastasis,recurrence.15-LOX-1 can metabolize linoleic acid and arachidonic acid to 13-S-HODE,15-HETE,respectively.These two metabolites can induce multiple cell differentiation and promote tumor cell apoptosis.Researchers confirmed that 5-LOX and platelet-type 12-LOX had a carcinogenic effect,and 8-LOX and 15-LOX-2 had anti-cancer effects,but there was still controversy over the function of 15-LOX-1.Therefore,the study of 15-lox-1function in breast cancer will help the human to understand its role in the development of breast cancer.In this study,we investigated the effect of 15-lox-1 on breast cancer cells in vitro and in vivo.The MCF-7,human breast cancer cells,were used in this study.This study was designed to investigate the effect of 15-lox-1 on the expression of AKT and tumor suppressor PPAR? in breast cancer,and to investigate the effect of 15-lox-1 on invasion and metastasis in vivo.The transfection of 15-lox-1 into MCF-7 cells was carried out in vitro ?Control cell was transfected with vector plasmids or just MCF-7.The study of invasion of cells was tested by Transwell chamber.We confirmed cell growth by cell count.Subsequently,we found that STAT3,AKT,phosphorylated STAT3 and phosphorylated AKT were changed in Western Blot.At the same time we confirmed that the substance that affects 15lox-1 in serum is albumin-binding free fatty acids.In order to confirm that 15-lox-1 metabolites have some functions,we used 15-loxhi-MCF-7 supernatants to treat MCF-7 and found that the substances in the supernatant also affected STAT3,AKT,phosphorylated STAT3 and phosphorylated AKT expression.To determine the relationship between 15-lox-1,phosphorylated AKT and PPAR?,we used 15-lox-1 agonists and antagonists in vitro to validate our hypothesis.Finally,we used the inhibitor to inhibit expression of 15-lox-1 to observe the effect on cells?Through all experiments,we observed that the expression of 15-lox-1 in breast cancer cells was related to the strong invasive clinical behavior of cells.The transfection of 15-lox-1 increased the invasion of cells and accelerated the growth in vitro.Our results show that free fatty acids can activate 15-lox-1 and produce 15-HETE and other metabolites.The role of 15-lox-1 in cancer biology is environmentally dependent.15-lox-1 can enhance phosphorylated STAT3 and phosphorylated AKT as a tumor promoter.But at the same time it can activate PPAR?,which makes 15-lox-1 function as a tumor suppressor.By inhibiting the expression of 15-lox-1,the growth rate of 15-Lox^hi-MCF-7 cells can be reduced and the expression of anti-apoptotic signals can be reduced.The viability of cells in hypoglycemic environment is reversed by the inhibitory.