| Breast cancer is a common malignant tumor with extremely high lethality,which is the number one problem for medical scholars.Not only humans,but pet dogs and cats are also prone to high incidence of breast tumors.This is still a big challenge for the development of new therapies for breast cancer and more accurate diagnosis and prognosis methods.Therefore,in order to better understand the biological mechanism of breast tumors,we need to find a new type of therapeutic target.The expression of mi RNA in a variety of body fluids is relatively stable,and it is currently a hotspot in the study of biomarkers for malignant tumors.At present,mi RNA has been confirmed to have an important relationship with a variety of cancers.It can not only perform the function of tumor suppressor gene,but also has the function of proto-oncogene.Protocarcinoma mi RNAs are highly expressed in tumors,which can promote tumor occurrence,growth,invasion,etc.,and play a positive regulatory role,while tumor suppressor mi RNAs are the opposite.Understanding/clarifying the molecular regulation mechanism of mi RNA helps us to fully understand the occurrence and development of breast tumors,and provides a scientific theoretical basis for further understanding and understanding of the underlying molecular mechanism of breast cancer.Therefore,mi RNA can be used as a potential biomarker for breast tumors,and will provide a new method for cancer treatment in the future.Previous studies have shown that microRNA-188-5p(mi R-188)regulates the cancer cells in liver cancer and gastric cancer.But,it is still unclear whether mi R-188 is involved in the development of breast cancer and its intrinsic molecular mechanism.In this study,we mainly used molecular biology techniques to deeply study the Rap2 c gene involved in the occurrence and development of breast cancer from multiple directions such as samples collected from veterinary clinics,mouse transplanted tumor models,and breast cancer cells.Explored the mi R-188 molecule that affects its expression explore the mechanism of interaction between their relation and its effect on breast cancer cell proliferation and metastasis.The MAPK signaling pathway plays a key role in many biological behaviors,including cell colonization,tumor invasion,stem cell-like phenotype,and resistance to chemotherapy.The Ras gene is involved in the Ras-MAPK signaling pathway,which regulates cell proliferation and malignant transformation.Rap2 c is a small G protein of the Ras family.Studies already proved that Rap2 c can promote the metastasis and invasion of cancer cells by activating the MAPK signaling pathway.Many studies also confirmed that Rap2 c is closely related to the occurrence and development of cancer,but little is known about the intrinsic role of Rap2 c in breast cancer.In order to clarify the relationship between mi R-188 and Rap2 c,this study aims to clarify the effects of mi R-188 and Rap2 c on breast cancer apoptosis and their potential molecular mechanisms.It is planned to study from the following aspects:1.Animal experiments: mi R-188 expression in canine breast tumor tissues and mouse breast transplantation tumors.q RT-PCR was used to detect mi R-188 expression in breast cancer tissues and adjacent tissues.The m RNAs expression levels reveals significantly lower than those of adjacent tumor tissues in canine breast tumor tissues and BALB / c mouse breast transplantation tumor tissues.2.In vitro experiments: mi R-188 mimics and inhibitors were transfected in vitro for mi R-188 overexpression and inhibition.Functional verification of mi R-188 and Rap2 c using techniques such as CCK-8,flow cytometry,scratch experiments,and western blotting;construction of a luciferase vector and prediction of the wild-type binding site of the target gene Rap2 c 3 'non-coding region Co-transfection of mi R-188 and mutant plasmids in vitro to verify the target gene of mi R-188;the effects of mi R-188 on key proteins in the MAPK pathway were determined using immunofluorescence and western blotting techniques.Results: mi R-188 is significantly low expressed in canine breast tumor tissue and mouse breast xenograft tumor.The overexpression of mi R-188 can significantly induce the apoptosis process of breast cancer cells.mi R-188 can also inhibit the proliferation and migration of cancer cells.The software and dual luciferase report analysis software predict and verify that Rap2 c is mi R-188 The target gene.Validation of target genes through in vitro cell experiments found that silencing Rap2 c can inhibit the growth and migration of breast cancer cells,and promote the process of breast cancer cell apoptosis.Western blot experiments verified that mi R-188 significantly inhibited the phosphorylation of the main proteins of ERK,JNK and p38 in the MAPK signaling pathway,and the immunofluorescence results also showed that mi R-188 inhibited the phosphorylation of p38 protein in the MAPK signaling pathway.mi R-188 can inhibit breast cancer by acting on the Rap2c/MAPK signaling pathway.Conclusion: mi R-188 inhibits the activation of MAPK signaling pathway by negatively regulating Rap2 c in breast cancer,leading to apoptosis of breast cancer cells and inhibiting their proliferation and migration.In conclusion,mi R-188,as a tumor suppressor,could play a potential therapeutic target for breast cancer. |
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