Transcriptional positive cofactor 4 promotes breast cancer proliferation and metastasis through c-Myc mediated Warburg effect.

BACKGROUND: The human positive cofactor 4 (PC4) is initially identified as a transcriptional cofactor and has an important role in embryonic development and malignant transformation. However, the clinical significance and the molecular mechanisms of PC4 in breast cancer development and progression are still unknown. METHODS: We investigated PC4 expression in 114 cases of primary breast cancer and matched normal breast tissue specimens, and studied the impact of PC4 expression as well as the molecular mechanisms of this altered expression on breast cancer growth and metastasis both in vitro and in vivo. RESULTS: PC4 was significantly upregulated in breast cancer and high PC4 expression was positively correlated with metastasis and poor prognosis of patients. Gene set enrichment analysis (GSEA) demonstrated that the gene sets of cell proliferation and Epithelial-Mesenchymal Transition (EMT) were positively correlated with elevated PC4 expression. Consistently, loss of PC4 markedly inhibited the growth and metastasis of breast cancer both in vitro and in vivo. Mechanistically, PC4 exerted its oncogenic functions by directly binding to c-Myc promoters and inducing Warburg effect. CONCLUSIONS: Our study reveals for the first time that PC4 promotes breast cancer progression by directly regulating c-Myc transcription to promote Warburg effect, implying a novel therapeutic target for breast cancer.

Allyl Isothiocyanate Inhibits the Proliferation of Renal Carcinoma Cell Line GRC-1 by Inducing an Imbalance Between Bcl2 and Bax.

BACKGROUND Because of the insensitivity of renal cell carcinoma (RCC) to both chemotherapy and radiotherapy, surgery remains the primary approach for anticancer treatment. However, patients who do not receive timely diagnoses may not be suitable for surgery, especially in the late phase of tumor development. Thus, the discovery of novel effective treatment is of great importance. Allyl isothiocyanate (AITC) can inhibit the proliferation and induce apoptosis in many cancer cells. In this paper, we report on an in vitro study to determine the effect of AITC on proliferation and apoptosis of RCC line GRC-1. MATERIAL AND METHODS CCK8 assay was used to detect cell proliferation under gradient concentrations of AITC. Flow cytometry was employed to evaluate cell apoptosis. Real-time fluorescent polymerase chain reaction quantified mRNA levels of Bax and Bcl-2 genes. Western blotting was further employed for protein expression assay. RESULTS AITC inhibited GRC-1 cell proliferation and induced cell apoptosis in a dose-dependent manner; it also elevated Bax while suppressing Bcl-2 gene expression at both mRNA and protein levels. In general, increasing concentration of AITC decreased Bcl-2/Bax ratio. CONCLUSIONS The inhibitory effect of AITC on GRC-1 cells is exerted via cell apoptosis, in which the imbalance of Bcl-2/Bax plays a significant role.

P53 and Murine Double Mimute 2 (MDM2) Expression Changes and Significance in Different Types of Endometrial Lesions.

BACKGROUND Endometrial lesions are common in obstetrics and gynecology, including endometrial polyps, uterine adenomyosis, and malignant endometrial adenocarcinoma. Endometrial lesions seriously affect women's health, fertility, quality of life, and life safety. As a pro-apoptosis gene, p53 is considered to be closely related with human tumors. Murine double mimute 2 (MDM2) is an oncogene that can promote tumor occurrence and development. P53 and MDM2 expression and significance in different types of endometrial lesions have not been fully elucidated. MATERIAL AND METHODS Normal endometrium, endometrial polyps, uterine adenomyosis, and endometrial adenocarcinoma tissue samples were collected. Real-time PCR was used to detect p53 and MDM2 mRNA expression. Immunohistochemical staining and Western blot analysis were applied to test p53 and MDM2 protein expression. Their correlation with clinical staging of endometrial adenocarcinoma was analyzed. RESULTS P53 and MDM2 mRNA and protein expression were significantly elevated in the endometrial polyps group and the endometrial adenocarcinoma group compared with the normal control group (P<0.05). Their levels increased more obviously in endometrial adenocarcinoma compared with endometrial polyps (P<0.05). P53 and MDM2 mRNA and protein expression were slightly enhanced in uterine adenomyosis compared with normal controls, but this difference lacked statistical significance (P>0.05). P53 and MDM2 mRNA and protein level showed a positive correlation. Significantly higher expression of p53 or MDM2 was observed in patients with stage III compared to those in patients with stage II. Higher expression was also observed in patients with stage II than in patients with stage I. CONCLUSIONS P53 and MDM2 mRNA and protein were elevated in endometrial polyps and endometrial adenocarcinoma and their expressions were correlated with clinical staging of endometrial adenocarcinoma. They can promote cancer occurrence and development, and can be treated to assist diagnosis and provide a reference for treatment.

A novel biosensor-based microarray assay for the visualized detection of CYP2C19 *2, *3, *4 and *5 polymorphisms.

BACKGROUND: A number of studies have indicated that the conversion of clopidogrel to its active metabolite is reduced in patients who carry the CYP2C19 *2, *3, *4 or *5 loss-of-function allele, resulting in decreased response of platelet to clopidogrel treatment and worse cardiovascular outcome. The aim of this study was to develop a novel biosensor-based microarray to visually detect CYP2C19 polymorphisms. METHODS: The target DNA was amplified from regions flanking the respective alleles using 5'-biotinylated reverse primer, and plasmids were prepared for the respective alleles. High stringency reversed hybridization, horseradish peroxidase-labeled streptavidin reaction, and color development, with multiple washes in different steps, were carried out and the results were recorded with an optical camera. The gene chips were tested for specificity, detection limit, intra- and inter-batch variations using the constructed plasmids. Finally, 88 clinical samples were assayed with this microarray as well as direct sequencing. RESULTS: The results could be seen with the naked eye. Concordance tests indicated that for alleles *2, *3, *4, and *5, the κ values between this assay and plasmids all reached 1.000. The detection limit was 5×10² cells/mL. Concordance test between direct sequencing and the microarray assay using 88 clinical samples gave rise to the κ value of 0.983, and p<0.01, indicating very high concordance. CONCLUSIONS: This novel biosensor-based microarray assay can amplify the signal in situ so that it can be detected by simple instruments or even the naked eyes. It is promising for clinical application in hospital laboratories.

Transcriptome Analysis and Epigenetics Regulation in the Hippocampus and the Prefrontal Cortex of VPA-Induced Rat Model.

Autism spectrum disorders (ASD) are a highly heterogeneous group of neurodevelopmental disorders caused by complex interaction between various genes and environmental factors. As the hippocampus and prefrontal cortex are involved in social recognition, they are the regions of the brain implicated in autism. The effects of prenatal exposure to valproic acid (VPA) can induce an ASD phenotype in both humans and rats; this tool is commonly used to model the complexity of ASD symptoms in the laboratory. However, researchers rarely undertake epigenetic regulation of the brain regions using this model. The present study has addressed this gap by examining gene expression abnormalities in the hippocampus and prefrontal cortex in the VPA rat model of ASD. mRNA and miRNA sequencing was performed on samples from the hippocampus and prefrontal cortex of the VPA model of autism. According to the analysis, 3000 mRNAs in the hippocampus and 2187 mRNAs in the prefrontal cortex showed a significant difference in expression between the VPA and saline groups. In addition, there were 115 DE miRNAs in the hippocampus and 14 DE miRNAs in the prefrontal cortex. Further, the predicted and validated target mRNA of DE miRNA enriched pathways involved neurotransmitter uptake, long-term synaptic depression, and AMPA receptor complex (anti-GluA2-b) in the hippocampus; as well as the neuroactive ligand-receptor interaction and regulation of postsynaptic membrane potential in the prefrontal cortex. This revealed the negative regulation network of miRNAs-mRNAs in the hippocampus and prefrontal cortex, while filtering out key genes (miR-10a-5p and Grm3). Finally, the significant variable miR-10a-5p and its negative regulated genes (Grm3) were verified in both brain regions by QPCR. Importantly, the fact that miR-10a-5p downregulated Grm3 in both the hippocampus and the prefrontal cortex may play a potentially significant role in the occurrence and development of autism. This study suggests that the VPA model has the potential to reproduce ASD-related hippocampus and prefrontal cortex abnormalities, at the epigenetic and transcriptional levels. Furthermore, the network of miRNAs-mRNAs was confirmed; this negative regulatory relationship may play a key role in determining the occurrence and development of autism. The study of this topic help better understand the pathogenesis of ASD.

Elevated hepatic multidrug resistance-associated protein 3/ATP-binding cassette subfamily C 3 expression in human obstructive cholestasis is mediated through tumor necrosis factor alpha and c-Jun NH2-terminal kinase/stress-activated protein kinase-signaling pathway.

UNLABELLED: Multidrug resistance-associated protein 3 (MRP3, ABC subfamily C [ABCC]3) plays an important role in protecting hepatocytes and other tissues by excreting an array of toxic organic anion conjugates, including bile salts. MRP3/ABCC3 expression is increased in the liver of some cholestatic patients, but the molecular mechanism of this up-regulation remains elusive. In this report, we assessed liver MRP3/ABCC3 expression in patients (n = 22) with obstructive cholestasis caused by gallstone blockage of bile ducts and noncholestatic patient controls (n = 22). MRP3/ABCC3 messenger RNA (mRNA) and protein expression were significantly increased by 3.4- and 4.6-fold, respectively, in these cholestatic patients where elevated plasma tumor necrosis factor alpha (TNFα) (4.7-fold; P < 0.01) and hepatic specificity protein 1 transcription factor (SP1) and liver receptor homolog 1 expression (3.1- and 2.1-fold at mRNA level, 3.5- and 2.5-fold at protein level, respectively) were also observed. The induction of hepatic MRP3/ABCC3 mRNA expression is significantly positively correlated with the level of plasma TNFα in these patients. In HepG2 cells, TNFα treatment induced SP1 and MRP3/ABCC3 expression in a dose- and time-dependent manner, where increased phosphorylation of c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK) was also detected. These inductions were significantly reduced in the presence of the JNK inhibitor, SP600125. TNFα treatment enhanced HepG2 cell nuclear extract-binding activity to the MRP3/ABCC3 promoter, but was abolished by SP600125, as demonstrated by electrophoretic mobility shift assay (EMSA). An increase in nuclear protein-binding activity to the MRP3/ABCC3 promoter, consisting primarily of SP1, was also observed in liver samples from cholestatic patients, as assessed by supershift EMSA assays. CONCLUSIONS: Our findings indicate that up-regulation of hepatic MRP3/ABCC3 expression in human obstructive cholestasis is likely triggered by TNFα, mediated by activation of JNK/SAPK and SP1.

Released dsDNA-triggered inflammasomes serve as intestinal radioprotective targets.

Objectives: Intestinal mucositis is the major side effect during abdominal or pelvic radiotherapy, but the underlying immunogen remains to be further characterised and few radioprotective agents are available. This study investigated the role of dsDNA-triggered inflammasomes in intestinal mucositis during radiotherapy. Methods: Pro-inflammatory cytokines were detected by ELISA. Radiation-induced intestinal injury in mice was analyzed by means of survival curves, body weight, HE staining of intestines, and intestinal barrier integrity. Western blot, immunofluorescence staining, co-immunoprecipitation assay and flow cytometry were used to investigate the regulatory role of dsDNA on inflammasomes. Results: Here, we show that a high level of IL-1ß and IL-18 is associated with diarrhoea in colorectal cancer (CRC) patients during radiotherapy, which accounts for intestinal radiotoxicity. Subsequently, we found that the dose-dependently released dsDNA from the intestinal epithelial cells (IECs) serves as the potential immunogenic molecule for radiation-induced intestinal mucositis. Our results further indicate that the released dsDNA transfers into the macrophages in an HMGB1/RAGE-dependent manner and then triggers absent in melanoma 2 (AIM2) inflammasome activation and the IL-1ß and IL-18 secretion. Finally, we show that the FDA-approved disulfiram (DSF), a newly identified inflammasome inhibitor, could mitigate intestinal radiotoxicity by controlling inflammasome. Conclusion: These findings indicate that the extracellular self-dsDNA released from the irradiated IECs is a potential immunogen to stimulate immune cells and trigger the subsequent intestinal mucositis, while blunting the dsDNA-triggered inflammasome in macrophages may represent an exciting therapeutic strategy for side effects control during abdominal radiotherapy.

Artesunate induces G0/G1 cell cycle arrest and iron-mediated mitochondrial apoptosis in A431 human epidermoid carcinoma cells.

The anticancer effects of artesunate (ART) have been well documented. However, its potential against skin cancer has not been explored yet. Herein we reported that 60 µmol/l ART effectively inhibited A431 (human epidermoid carcinoma cells) growth but not that of HaCaT (normal human keratinocyte cells). Our results revealed that ART induced cell cycle arrest at G0/G1 phase through the downregulation of cyclin A1, cyclin B, cyclin D1, Cdk2, Cdk4, and Cdk6. This correlated with the upregulation of p21 and p27. The 5-bromodeoxyuridine incorporation assay also indicated that ART treatment reduced DNA synthesis in a time-dependent manner. Furthermore, ART induced mitochondrial apoptosis, as evidenced by annexin V/propidium iodide staining and western blot analysis. Interestingly, ART-induced apoptosis diminished under iron-deficient conditions but intensified under iron-overload conditions. Taken together, these findings demonstrated the potential of ART in treating skin cancer through the induction of G0/G1 cell cycle arrest and iron-mediated mitochondrial apoptosis and supported further investigations in other test systems.

[Expression of ezrin in human non-small cell lung cancer and its relationship with metastasis and prognosis].

OBJECTIVE: To explore the expression of ezrin protein in human non-small cell lung cancer (NSCLC) tissues and lung cancer cell lines, and the association between the expression of ezrin protein and the expression of E-cadherin and CD44V6 proteins. METHODS: The expression of ezrin protein and mRNA in lung cancer cell lines was detected by RT-PCR and Western blotting. Ezrin, E-cadherin and CD44V6 were detected by immunohistochemical SP staining in tumor tissues from 150 lung cancer cases and in adjacent normal lung tissues from 30 patients. Furthermore, the expression of ezrin in 30 freshly-taken NSCLC tissues was also detected by Western blot. RESULTS: The expression of ezrin protein and mRNA was up-regulated in highly metastatic human lung cancer. The positive rate of ezrin, E-cadherin and CD44V6 expression in the lung cancer was 61.3%, 54.0% and 58.7%, respectively. The up-regulation of ezrin expression was significantly correlated with lymph node metastasis, but not correlated with age, sex, tumor size, histological type, clinical TNM system and pathological grade. Western blot analysis showed that the level of ezrin in the NSCLC tissues was significantly higher than that in the normal tissues (t = 5.013, P < 0.01). Survival analysis showed that the 5-year survival rate of patients with negative ezrin expression was 29.3%, significantly higher than that of patients with positive ezrin expression (15.2%, χ(2) = 4.128, P = 0.042). Multivariate Cox regression analysis showed that ezrin expression (RR = 3.012, P = 0.047) and lymph node metastasis (RR = 4.827, P = 0.035) were significantly independent prognostic factors for patients with lung cancer. Furthermore, a negative correlation was observed between the expressions of ezrin and E-cadherin in lung cancer, and a positive correlation between the expressions of ezrin and CD44V6 in lung cancer. CONCLUSIONS: Ezrin, E-cadherin and CD44V6 play an important role in the regulation of growth and meastasis of lung cancer. Combined detection of ezrin, E-cadherin and CD44V6 expression is helpful in evaluating the metastasis and prognosis of non-small cell lung cancer.

Peripheral CD4 +CD8 + double positive T cells: A potential marker to evaluate renal impairment susceptibility during systemic lupus erythematosus.

Lupus nephritis (LN) has a high incidence in systemic lupus erythematosus (SLE) patients, but there is a lack of sensitive predictive markers. The purpose of the study was to investigate the association between the CD4 +CD8 + double positive T (DPT) lymphocytes and LN. The study included patients with SLE without renal impairment (SLE-NRI), LN, nephritic syndrome (NS), or nephritis. Peripheral blood lymphocyte subsets were analyzed by flow cytometry. Biochemical measurements were performed with peripheral blood in accordance with the recommendations proposed by the National Center for Clinical Laboratories. The proportions of DPT cells in the LN group were significantly higher than that in the SLE-NRI group ( t=4.012, P<0.001), NS group ( t=3.240, P=0.001), and nephritis group ( t=2.57, P=0.011). In the LN group, the risk of renal impairment increased significantly in a DPT cells proportion-dependent manner. The risk of LN was 5.136 times (95% confidence interval, 2.115-12.473) higher in cases with a high proportion of DPT cells than those whose proportion of DPT cells within the normal range. These findings indicated that the proportion of DPT cells could be a potential marker to evaluate LN susceptibility, and the interference of NS and nephritis could be effectively excluded when assessing the risk of renal impairment during SLE with DPT cell proportion.

Artesunate induces ER-derived-ROS-mediated cell death by disrupting labile iron pool and iron redistribution in hepatocellular carcinoma cells.

Aberrant iron homeostasis is a typical characteristic of Hepatocellular carcinoma (HCC), and perturbation of iron metabolism is an effective strategy for HCC therapy. However, there are few safe and effective targeting agents available in clinical practices. The artemisinin and its derivatives have shown potential anti-cancer activity by disturbing cellular iron homeostasis, but the specific mechanism is still unclear. In this study, we demonstrate that Artesunate (ART), a water-soluble anti-malaria agent in clinical use, can regulate the labile iron pool (LIP) and effectively induce ROS-dependent cell death in multiple HCC cells. Mechanistically, ART increases the LIP by promoting lysosomal degradation of iron-storage protein ferritin through acidizing lysosomes. Then the accumulation of labile iron in the endoplasmic reticulum (ER) promotes excessive reactive oxygen species (ROS) production and severe ER disruption, which leads to cell death. Our results provide a new understanding of how ART modulates iron metabolism in HCC cells at the subcellular level, demonstrate the significance of endoplasmic reticulum as iron-vulnerability of HCC cells. More importantly, our findings suggest ART is a safe and potential anti-HCC agent via disturbing iron homeostasis.

Mitigation of radiation-induced pulmonary fibrosis by small-molecule dye IR-780.

Radiation-induced pulmonary fibrosis (RIPF) is a common complication during thoracic radiotherapy, but there are few effective treatments. Here, we identify IR-780, a mitochondria-targeted near-infrared (NIR) dye, can selectively accumulate in the irradiated lung tissues. Besides, IR-780 significantly alleviates radiation-induced acute lung injury and fibrosis. Furthermore, our results show that IR-780 prevents the differentiation of fibroblasts and the release of pro-fibrotic factors from alveolar macrophages induced by radiation. Besides, IR-780 downregulates the expression of glycolysis-associated genes, and 2-Deoxy-d-glucose (2-DG) also prevents the development of fibrosis in vitro, suggesting radioprotective effects of IR-780 on RIPF might be related to glycolysis regulation. Finally, IR-780 induces tumour cell apoptosis and enhances radiosensitivity in representative H460 and A549 cell lines. These findings indicate that IR-780 is a potential therapeutic small-molecule dye during thoracic radiotherapy.

Near-infrared oxidative phosphorylation inhibitor integrates acute myeloid leukemia-targeted imaging and therapy.

Acute myeloid leukemia (AML) is a deadly hematological malignancy with frequent disease relapse. The biggest challenge for AML therapy is the lack of methods to target and kill the heterogeneous leukemia cells, which lead to disease relapse. Here, we describe a near-infrared (NIR) fluorescent dye, IR-26, which preferentially accumulates in the mitochondria of AML cells, depending on the hyperactive glycolysis of malignant cell, and simultaneously impairs oxidative phosphorylation (OXPHOS) to exert targeted therapeutic effects for AML cells. In particular, IR-26 also exhibits potential for real-time monitoring of AML cells with an in vivo flow cytometry (IVFC) system. Therefore, IR-26 represents a novel all-in-one agent for the integration of AML targeting, detection, and therapy, which may help to monitor disease progression and treatment responses, prevent unnecessary delays in administering upfront therapy, and improve therapeutic efficiency to the residual AML cells, which are responsible for disease relapse.

Acceleration of ageing via disturbing mTOR-regulated proteostasis by a new ageing-associated gene PC4.

Research on ageing-associated genes is important for investigating ageing and anti-ageing strategies. Here, we firstly reported that the human positive cofactor 4 (PC4), a multifunctional and highly conserved nucleoprotein, is accumulated and activated during ageing and causes global accelerated ageing process by disrupting proteostasis. Mechanistically, PC4 interacts with Sin3-HDAC complex and inhibits its deacetylated activity, leads to hyper-acetylation of the histones at the promoters of mTOR-related genes and causes mTOR signalling activation. Accordingly, mTOR activation causes excessive protein synthesis, resulting in impaired proteostasis and accelerated senescence. These results reveal a new biological function of PC4 in vivo, recognizes PC4 as a new ageing-associated gene and provides a genetically engineered mouse model to simulate natural ageing. More importantly, our findings also indicate that PC4 is involved in histone acetylation and serves as a potential target to improve proteostasis and delay ageing.

Pharmaceutical targeting of succinate dehydrogenase in fibroblasts controls bleomycin-induced lung fibrosis.

Idiopathic pulmonary fibrosis (IPF) is characterized by excessive deposition of extracellular matrix in the lung with fibroblast-to-myofibroblast transition, leading to chronically compromising lung function and death. However, very little is known about the metabolic alterations of fibroblasts in IPF, and there is still a lack of pharmaceutical agents to target the metabolic dysregulation. Here we show a glycolysis upregulation and fatty acid oxidation (FAO) downregulation in fibroblasts from fibrotic lung, and perturbation of glycolysis and FAO affects fibroblasts transdifferentiation. In addition, there is a significant accumulation of succinate both in fibrotic lung tissues and myofibroblasts, where succinate dehydrogenase (SDH) operates in reverse by reducing fumarate to succinate. Then succinate contributes to glycolysis upregulation and FAO downregulation by stabilizing HIF-1α, which promotes the development of lung fibrosis. In addition, we identify a near-infrared small molecule dye, IR-780, as a targeting agent which stimulates mild inhibition of succinate dehydrogenase subunit A (SDHA) in fibroblasts, and which inhibits TGF-ß1 induced SDH and succinate elevation, then to prevent fibrosis formation and respiratory dysfunction. Further, enhanced cell retention of IR-780 is shown to promote severe inhibition of SDHA in myofibroblasts, which may contribute to excessive ROS generation and selectively induces myofibroblasts to apoptosis, and then therapeutically improves established lung fibrosis in vivo. These findings indicate that targeting metabolic dysregulation has significant implications for therapies aimed at lung fibrosis and succinate dehydrogenase is an exciting new therapeutic target to treat IPF.

Improvement of obesity-associated disorders by a small-molecule drug targeting mitochondria of adipose tissue macrophages.

Pro-inflammatory activation of adipose tissue macrophages (ATMs) is causally linked to obesity and obesity-associated disorders. A number of studies have demonstrated the crucial role of mitochondrial metabolism in macrophage activation. However, there is a lack of pharmaceutical agents to target the mitochondrial metabolism of ATMs for the treatment of obesity-related diseases. Here, we characterize a near-infrared fluorophore (IR-61) that preferentially accumulates in the mitochondria of ATMs and has a therapeutic effect on diet-induced obesity as well as obesity-associated insulin resistance and fatty liver. IR-61 inhibits the classical activation of ATMs by increasing mitochondrial complex levels and oxidative phosphorylation via the ROS/Akt/Acly pathway. Taken together, our findings indicate that specific enhancement of ATMs oxidative phosphorylation improves chronic inflammation and obesity-related disorders. IR-61 might be an anti-inflammatory agent useful for the treatment of obesity-related diseases by targeting the mitochondria of ATMs.

High-altitude adaptation of yak based on genetic variants and activity of lactate dehydrogenase-1.

This study investigates the molecular mechanism by which yaks (Bos grunniens) adapt to hypoxia based on lactate dehydrogenase (LDH). Three LDH1 variants of the yak were revealed in tissue extracts by electrophoresis, including LDH1-F, LDH1-M, and LDH1-S. Kinetic analysis using purified LDH1 variants showed that the yak LDH1-M variant exhibited a similar K (m) (NADH) and the same mobility on a gel as bovine LDH1, and the LDH1-F variant showed significant differences in K (m) values for NADH or pyruvate from the other two variants of yak LDH1 and bovine LDH1. Among the three muscles assayed, yak longissimus dorsi showed the highest LDH activity and the lowest malate dehydrogenase (MDH) activity; heart muscle was exactly the opposite. Our results suggest that the three LDH1 variants might play an important role in the adaptation to hypoxia.

[Expression of alpha-tubulin and MDR1 and their correlation with the biological features of non-small cell lung carcinoma].

OBJECTIVE: To detect the expression of alpha-tubulin and MDR1 in human non-small cell lung carcinoma (NSCLC), and to clarify their clinical significance. METHODS: Paraffin embedded tissues from 158 primary non-small lung carcinomas and 30 paracancerous lung tissues were examined for expression of alpha-tubulin and MDR1 by immunohistochemistry (SP method). 30 freshly taken NSCLC tissues were examined by Western blot analysis. The relationship between alpha-tubulin and MDR1 expression and the biological features of lung carcinoma was analyzed. RESULTS: The positive rate of alpha-tubulin and MDR1 expressions in the lung carcinomas was 65.2% and 51.3%, respectively. There was no expression of either of them in 30 paracancerous lung tissues. Western blot analysis showed that the level of alpha-tubulin and MDR1 expressions in NSCLC tissues were 0.49 +/- 0.06 and 0.56 +/- 0.04, respectively, significantly higher than that in paracancerous tissues (0.07 +/- 0.01) (t = 3.693 and t = 6.769, P < 0.01). The positive rate of alpha-tubulin expression was gradually increased with tumor progression, significantly higher in III-IV stage cancers and in poorly differentiated carcinomas (both P < 0.01). There was a distinct statistically significant difference between stage I, stage II and III, and stage IV. The positive rate of alpha-tubulin in well-moderately differentiated carcinomas was lower than that in poorly differentiated ones. There was no significant correlation with age, sex, tumor size, histological type, clinical TNM system and lymph node metastasis. The positive rate of MDR1 was not correlated with sex, age, tumor size, pathological grading, clinical TNM stages and lymph node metastasis. But the positive rate of MDR1 in adenocarcinoma was significantly higher than that in squamous carcinoma and undifferentiated large cell carcinomas (P < 0.01). alpha-tubulin and MDR1 expression had no impact on the outcome of chemotherapy (chi(2) = 0.69 and 1.30, P > 0.05, respectively). Univariate analysis showed that the 5-year survival rate of patients with negative alpha-tubulin and MDR1 expression was 30.7% and 28.5%, respectively, significantly higher than that of patients with positive alpha-tubulin and MDR1 expression (13.5% and 11.8%, respectively) (chi(2) = 20.69 and 15.52, P < 0.01, respectively), and multivariate Cox regression analysis showed that alpha-tubulin (RR = 3.287, P = 0.006) and clinical TNM stage (RR = 1.954, P = 0.025) were significantly independent predictive factor for patients with lung cancer, MDR1 and other factors could not be used as an independent predicitive factors. However, there was no significant correlation between the expression of alpha-tubulin and MDR1 in lung carcinoma(r = 0.093, P > 0.05). CONCLUSION: The expression of alpha-tubulin and MDR1 may play an important role in the development and progression of human non-small cell lung carcinoma. Combined detection could be considered as an important index for predicting prognosis of lung carcinoma.

Metformin mitigates gastrointestinal radiotoxicity and radiosensitises P53 mutation colorectal tumours via optimising autophagy.

BACKGROUND AND PURPOSE: There is an urgent but unmet need for mitigating radiation-induced intestinal toxicity while radio sensitising tumours for abdominal radiotherapy. We aimed to investigate the effects of metformin on radiation-induced intestinal toxicity and radiosensitivity of colorectal tumours. EXPERIMENTAL APPROACH: Acute and chronic histological injuries of the intestine from mice were used to assess radioprotection and IEC-6 cell line was used to investigate the mechanisms in vitro. The fractionated abdominal radiation model of HCT116 and HT29 tumour grafts was used to determine the effects on colorectal cancer. KEY RESULTS: Metformin alleviated radiation-induced acute and chronic intestinal toxicity by optimising mitophagy which was AMPK-dependent. In addition, our data indicated that metformin increased the radiosensitivity of colorectal tumours with P53 mutation both in vitro and in vivo. CONCLUSION AND IMPLICATIONS: Metformin may be a radiotherapy adjuvant agent for colorectal cancers especially those carrying P53 mutation. Our findings provide a new strategy for further precise clinical trials for metformin on radiotherapy.