Explore The Expression Of MCCC2,GLUD1 And P38 MAPK In Non-small Cell Lung Cancer And Its Clinicopathologic Significance

Background: Lung cancer is the main cause of cancer mortality worldwide and is one of the most common malignant tumours in China.Based on its increasing incidence and mortality,lung cancer has become a public health problem and a huge burden on society in China.Lung cancer includes the two main groups of non-small cell lung cancer(NSCLC)and small cell lung cancer(SCLC).Small cell lung cancer accounts for about 15% of all lung cancers.The main histological types of NSCLC are adenocarcinoma and squamous carcinoma,which account for about 80% of NSCLC.Rare types include adenosquamous carcinoma,sarcomatoid carcinoma and large cell carcinoma.In recent years,the incidence of squamous lung cancer tends to decline,while the incidence of adenocarcinoma of the lung is on the rise and has surpassed that of squamous lung cancer.Currently,the main driver genes of non-small cell lung cancer are EGFR、NTRK、ROS1、ALK、KRAS、BRAF、TET and MET.With the continuous discovery of driver genes,corresponding targeted drugs have been developed for individualized and precise treatment,and molecular targeted therapy guided by driver genes has achieved fruitful results.In the future,more driver genes need to be discovered and more factors that are beneficial to lung cancer treatment and prognosis need to be identified to improve the efficacy and survival rate of lung cancer patients.Methylcrotonyl coenzyme a carboxylase 2(MCCC2),a subunit of3-methylcrotonyl coenzyme a carboxylase(MCC),is involved in the fourth step of the mitochondrial enzyme MCC-catalyzed leucine catabolic pathway and belongs to a family of biotin-dependent carboxylases.deficiency of MCCC2 is associated with obesity,insulin resistance and dyslipidaemia.Studies have shown that leucine knockdown inhibits cell proliferation,migration and invasion and that leucine promotes cancer growth.In contrast,MCCC2,a mitochondrial enzyme that catalyzes leucine catabolism,and MCCC2 expression also has a tumour-promoting effect.The literature reports that MCCC2 overexpression promotes the proliferation of breast,colorectal and liver cancer as well as prostate cancer cells with poor prognosis.Glutamate dehydrogenase 1(GLUD1)is a mitochondrial enzyme found mainly in liver,kidney and cardiac mitochondria and plays a key role in glutamine metabolism.High expression of GLUD1 promotes glutamine catabolism,and in some malignant tumours,tumour cell growth is also closely associated with glutamine catabolism.The literature reports that GLUD1 expression is abnormally elevated in breast cancer,hepatocellular carcinoma,colon cancer and other tumours,and enhances the invasive migration ability of tumour cells.Known as cytokine-suppressive anti-inflammatory drug binding protein(CSBP),P38 MAPK,also known as stress-activated protein kinase,plays a key role in inflammation and tissue homeostasis.P38 MAPK pathway has oncogenic functions and promotes cancer cell proliferation,survival and invasion through involvement in cancer invasion,inflammation and angiogenesis.The literature reports that the P38 MAPK pathway promotes the malignant progression of colorectal,esophageal and breast cancers and is an important pathway for tumor invasion and metastasis.It has also been shown that the P38 MAPK pathway is involved in the regulation of acute lung injury and other mechanisms.Objective: To investigate the expression of MCCC2,GLUD1 and P38 MAPK in non-small cell lung cancer and their clinicopathological significance.Methods: One hundred and twenty-eight surgical specimens of non-small cell lung cancer were collected,and wax blocks with cancer and paracancerous tissues were selected.The selected wax blocks with cancerous tissues were grouped according to the WHO histological classification criteria for lung cancer in 2021,with 32 cases each of high and medium differentiated adenocarcinoma,low differentiated adenocarcinoma,high and medium differentiated squamous carcinoma and low differentiated squamous carcinoma.All patients underwent surgery at the First Affiliated Hospital of Dalian Medical University from January 2019 to May 2022.None of the patients received chemotherapy or radiotherapy,immunotherapy,or targeted therapy before surgery.Each pathological diagnosis was performed by two doctors.Clinical data were collected including the patient’s age,gender,tumour size(maximum diameter),pTNM,metastases in lymph nodes,distant metastases,tumour histological type and degree of differentiation.The selected cancer tissue wax blocks were grouped according to different degrees of differentiation to produce tissue microarrays.Immunohistochemical staining for MCCC2,GLUD1 and P38 MAPK was performed and the staining results were scored,and finally the data were analysed using SPSS version 26.0 software.Results:1.MCCC2 showed overexpression in NSCLC tissues,while it was weakly expressed or not expressed in paraneoplastic tissues.The high expression rate of MCCC2 in NSCLC tissues was 61.7%,and the expression level was significantly higher than that of 7% in paraneoplastic tissues.The results were statistically significantly different(P<0.01).the high expression rate of MCCC2 in lung adenocarcinoma tissues was 62.5% and in lung squamous cell carcinoma tissues was60.9%,the difference between the two results was not statistically significant(P>0.05).the high expression rate of MCCC2 in NSCLC high and medium differentiation group was 57.8% and in NSCLC low differentiation group the high expression rate was 65.6%.The difference was not statistically significant(P>0.05).The high expression rate of MCCC2 was 59.4% in the highly differentiated group of lung adenocarcinoma and65.6% in the poorly differentiated group of lung adenocarcinoma.The difference between the two results was not statistically significant(P>0.05).56.3% of MCCC2 was highly expressed in the high-senior differentiation group of lung squamous cell carcinoma and 62.5% in the low differentiation group of lung squamous cell carcinoma.The differences were not statistically significant(P>0.05).2.Overexpression of MCCC2 in non-small cell lung cancer correlated with stage of pTNM.The high expression rate was 38.5% in pTNM stage Ⅰ-Ⅱ and 59.5% in pTNM stage Ⅲ-Ⅳ,The difference wasstatistically significant(P<0.05).In contrast,there was no significant correlation between MCCC2 expressionand gender,age,tumour size(maximum diameter),a history of smoking,lymph node metastasis,and neurological invasion(P>0.05).3.GLUD1 was highly expressed in non-small cell lung cancer tissues and weakly expressed or not expressed in paraneoplastic tissues.The high expression rate of GLUD1 in non-small cell lung cancer tissues was 54.7%,which was significantly higher than that in normal tissues was 9.4%.The high expression rate of GLUD1 in lung adenocarcinoma tissues was 56.3% and in lung squamous carcinoma tissues was53.1%,which was statistically significantly different(P<0.01).The difference was not statistically significant(P>0.05).The high expression rate of GLUD1 was 48.4% in the high and medium differentiation groups of non-small cell lung cancer and 60.9% in the low differentiation group of non-small cell lung cancer.The difference was not statistically significant(P>0.05).43.8% of GLUD1 was highly expressed in the high and medium differentiated lung adenocarcinoma and 68.8% in the low differentiated lung adenocarcinoma.The difference was statistically significant(P<0.05).The high expression rate of GLUD1 was 53.1% in high and medium differentiated lung squamous carcinoma and 53.1% in low differentiated lung squamous carcinoma.The difference was not statistically significant(P>0.05).4.Overexpression of GLUD1 in non-small cell lung cancer correlated with lymph node metastasis and pTNM.The overexpression rate of GLUD1 in samples with lymph node metastasis was 64.7%,while the overexpression rate of GLUD1 in samples without lymph node metastasis was 41.5%,The difference was statistically significant(P<0.05).The high expression rate was 41.8% in pTNM stage Ⅰ-Ⅱ and 64.9% in pTNM stage Ⅲ-Ⅳ,The difference was statistically significant(P<0.05).In contrast,GLUD1 expression was not significantly correlated with gender,age,tumour size(maximum diameter),history of smoking,or presence of neurological invasion(P>0.05).5.P38 MAPK was highly expressed in non-small cell lung cancer tissues and weakly expressed in paraneoplastic tissues.The high expression rate of P38 MAPK in non-small cell lung cancer tissues was 82.8%,which was significantly higher than that of 16.4% in normal tissues.The difference was statistically significant(P<0.01).87.5%of P38 MAPK was highly expressed in lung adenocarcinoma tissues and 78.1% in lung squamous carcinoma tissues.The difference was not statistically significant(P>0.05).84.4% of P38 MAPK was highly expressed in non-small cell lung cancer tissues with high grade differentiation and 81.3% in non-small cell lung cancer tissues with low grade differentiation.The difference was not statistically significant(P>0.05).P38 MAPK was highly expressed in 81.2% of the high and medium differentiated lung adenocarcinoma and 68.7% of the low differentiated lung adenocarcinoma.The differencewas not statistically significant(P>0.05).The high expression rate of P38 MAPK was 75% in high and medium differentiated lung squamous carcinoma and81.2% in low differentiated lung squamous carcinoma.The differences were not statistically significant(P>0.05).6.Overexpression of P38 MAPK in non-small cell lung cancer correlated with a patient’s smoking history.The overexpression rate of P38 MAPK in samples from patients with smoking history was 71.4%,while the overexpressionrate of P38 MAPK in samples from patients without smoking history was 86.2%,The difference was statistically significant(P<0.05).In contrast,there was no significant correlation between P38 MAPK expression and gender,age,tumor size(maximum diameter),pleural invasion,nerve invasion and lymph node metastasis,and pTNM stage(P>0.05).7.The expression of MCCC2,GLUD1 and P38 MAPK did not correlate significantly in non-small cell lung cancer(P>0.05).the expression of MCCC2 and GLUD1 did not correlate significantly in lung adenocarcinoma and squamous lung cancer(P>0.05).the expression of MCCC2 and GLUD1 correlated inpoorly differentiated lung adenocarcinoma(P<0.05),The two show a positive correlation.In contrast,there was no significant correlation between MCCC2 and GLUD1 expression in high and medium differentiated lung adenocarcinoma,low differentiated lung squamous carcinoma and high and medium differentiatedlung squamous carcinoma(P>0.05).8.The expression of MCCC2 correlated with P38 MAPK in lung adenocarcinoma(P<0.05),The two show a positive correlation.The expression of MCCC2 and P38 MAPK in squamous lung cancer was not correlated(P>0.05).The expression of MCCC2 and P38 MAPK in poorly differentiated lung adenocarcinoma was correlated(P<0.05),The two show a positive correlation.In contrast,there was no significant correlation(P>0.05)between the expression of MCCC2 and P38 MAPK in high and medium differentiated lung adenocarcinoma,low differentiated lung squamous carcinoma and high and medium differentiated lung squamous carcinoma.9.There was no significant correlation between the expression of GLUD1 and P38 MAPK in lung adenocarcinoma and lung squamous carcinoma(P>0.05).There was no significant correlation between the expression of GLUD1 and P38 MAPK in high and low differentiated lung adenocarcinoma and high and low differentiated lung squamous carcinoma(P>0.05).Conclusion:1.The expression level of MCCC2 in non-small cell lung cancer was significantly higher than that in paraneoplastic tissues.overexpression of MCCC2 in non-small cell lung cancer was positively correlated with the stage of pTNM.2.The expression level of GLUD1 in non-small cell lung cancer was significantly higher than that in normal lung tissues.the expression of GLUD1 in poorly differentiated lung adenocarcinoma was higher than that in highly differentiated lung adenocarcinoma.overexpression of GLUD1 in non-small cell lung cancer was positively correlated with lymph node metastasis and positively correlated with the stage of pTNM.3.The expression levels of P38 MAPK were all significantly higher in non-small cell lung cancer than in normal lung tissue.The overexpression of P38 MAPK in non-small cell lung cancer was positively correlated with smoking history in patients.4.The expression of MCCC2,GLUD1 and P38 MAPK did not correlate in non-small cell lung cancer.In hypofractionated lung adenocarcinoma MCCC2 correlated with GLUD1 expression,Present positive correlation.MCCC2 correlated with P38 MAPK expression in lung adenocarcinoma,Present positive correlation.In hypofractionated lung adenocarcinoma MCCC2 correlated with P38 MAPK expression,Present positive correlation.MCCC2,GLUD1 and P38 MAPK can be considered as potential prognostic biomarkers and therapeutic targets for non-small cell lung cancer,and as potential differential diagnostic indicators between non-small cell lung cancer and other benign alveolar epithelial-derived tumours.