Asmitananda Thakur

Differentially expressed glycosylated patterns of α-1-antitrypsin as serum biomarkers for the diagnosis of lung cancer

Lung cancer is the most common malignancy worldwide. Thus, there is a critical need for diagnostic biomarkers with adequate sensitivity and specificity for lung cancer detection. Glycans in glycoproteins are significantly altered in cancer, and may serve as a tool for identifying potential diagnostic biomarkers. Recent studies have reported changes in α-1-antitrypsin (A1AT) glycosylation in lung cancer serum, tissue and cell lines. In this study, a lectin microarray was used to detect glycosylation changes in serum A1AT from patients with lung adenocarcinoma (ADC), squamous cell lung cancer, small-cell lung cancer (SCLC) and benign pulmonary diseases. Differentially expressed glycosylated patterns of A1AT were identified by lectin arrays and were confirmed by lectin-based enzyme-linked immunosorbent assay (ELISA). We found that galactosylated A1AT could distinguish non-small-cell lung cancer (NSCLC) from benign pulmonary diseases (AUC = 0.834); fucosylated A1AT showed exceptional capability in distinguishing ADC from benign diseases (AUC = 0.919) or other lung cancer subtypes (AUC = 0.844), and A1AT containing poly-LacNAc could detect SCLC from benign diseases (AUC = 0.905) or NSCLC (AUC = 0.707). The present study indicates that glycosylated patterns of A1AT may serve as potential biomarkers for detection of lung cancer. Further studies in larger sample sizes are necessary to validate the clinical utility of these markers.

Diagnostic significance of S100A2 and S100A6 levels in sera of patients with non-small cell lung cancer.

Biochemical markers play a significant role in the diagnosis of lung cancer. Recent studies have demonstrated a link involving S100 Calcium Binding Proteins (S100A2, S100A6) and non-small cell lung cancer (NSCLC), but the expediency of their serum levels in NSCLC has not been established. In this study, we evaluate the potential of serum S100A2 and S100A6 levels as diagnostic markers for NSCLC. Enzyme-linked immunosorbent assay (ELISA) was performed to detect the levels of S100A2 and S100A6 in 141 NSCLC patients and 150 healthy subjects. Serum levels of the two proteins in patients with NSCLC were higher compared to healthy controls (P = 0.0002 for S100A2 and P < 0.0001 for S100A6). Moreover, the levels of S100A2 and S100A6 were higher in the sera of stage I/II NSCLC patients compared to healthy controls with P = 0.01 and <0.0001, respectively. Receiver operating characteristic (ROC) analysis showed that S100A2 could distinguish NSCLC patients from healthy controls (AUC = 0.646), and S100A6 could also identify NSCLC (AUC = 0.668). Meanwhile, these two proteins showed notable capabilities for distinguishing stage I/II NSCLC from healthy controls (AUC = 0.708 for S100A2 and AUC = 0.702 for S100A6). Our results indicate that serum levels of S100A2 and S100A6 are significantly elevated in early stage NSCLC and may have the potential for NSCLC biomarker. Further studies with large sample population would help validate our findings.

Polymorphisms in the TERT gene are associated with lung cancer risk in the Chinese Han population.

Lung cancer has the highest mortality rate among cancers; however, its nosogenesis is still unclear. Genome-wide association studies have shown that the telomerase reverse transcriptase (TERT) gene, located in the chromosome 5p15.33 region, is one of the genes associated with the risk of lung cancer. In this case–control study, we genotyped 11 tag single-nucleotide polymorphisms of the TERT gene to evaluate their association with lung cancer risk in the Han Chinese population. Two tag single-nucleotide polymorphisms were found to be associated with lung cancer risk on using the &khgr;2-test: rs4246742 [odds ratio (OR)=0.77, 95% confidence interval (CI) 0.60–0.98; P=0.03] and rs2853672 (OR=1.26, 95% CI 1.01–1.57; P=0.045). By using SNPStats software we also found rs2242652 (OR=1.47, 95% CI 1.02–2.13; P=0.04) in the dominant model and rs2736098 (OR=1.38, 95% CI 1.06–1.80; P=0.017), rs2853672 (OR=1.41, 95% CI 1.11–1.80; P=0.0048), and rs4246742 (OR=0.75, 95% CI 0.58–0.97; P=0.029) in the log-additive model. ‘T/C-T/T’ of rs10069690 conferred an increased risk for male sex in the dominant model (OR=1.80, 95% CI, 1.05–3.08; P=0.03) and ‘TC’ increased risk for male sex in the overdominant model (OR=1.85, 95% CI, 1.08–3.17; P=0.031). Our findings, combined with previous studies, suggest that polymorphisms in the TERT gene contribute to the risk for lung cancer in the Chinese Han population.

miRNA-204 suppresses human non-small cell lung cancer by targeting ATF2.

MicroRNAs (miRNAs) play a critical role in cancer development and progression. Deregulated expression of miR-204 has been reported in several cancers, but the mechanism through which miR-204 modulates human non-small cell lung cancer (NSCLC) is largely unknown. In this study, we investigate the expression and functional role of miR-204 in human NSCLC tissues and cell lines. RNA isolation, qRT-PCR, MTT, colony formation assay, cell cycle assay, cell apoptosis assay, cell migration assay, and Western blot were performed. Statistical analysis was performed using SPSS 18.0 software and statistical significance was accepted at p value <0.05. miR-204 level was significantly reduced in NSCLC tissues as compared to that of non-neoplastic tissues. Transient over-expression of miR-204 by transfecting with miR-204 mimics suppressed NSCLC cell proliferation, migration, and induced apoptosis and G1 arrest, whereas inhibition of miR-204 showed the converse effects. Additionally, activating transcription factor 2 (ATF2), an important transcription factor, was demonstrated as a potential target gene of miR-204. Subsequent investigations found a negative correlation between miR-204 level and ATF2 expression in NSCLC tissue samples. Moreover, we observed that miR-204 expression inversely affected endogenous ATF2 expression at both mRNA and protein levels in vitro. Taken together, miR-204 may act as a tumor suppressor by directly targeting ATF2 in NSCLC.

Blockade efficacy of MEK/ERK-dependent autophagy enhances PI3K/Akt inhibitor NVP-BKM120's therapeutic effectiveness in lung cancer cells

NVP-BKM120 (BKM120) is a new pan-class I phosphatidylinositol-3 kinase (PI3K) inhibitor and has been tested in clinical trials as an anticancer agent. In this study, we determined whether BKM120 induces autophagy and the impact of autophagy induction on BKM120s growth-inhibitory activity. BKM120 potently induced elevation of autophagosome-bound type II LC3 (LC3-II) protein, predominantly in cell lines insensitive to BKM120, thereby inducing autophagy. The presence of lysosomal protease inhibitor chloroquine further enhanced the levels of LC3-II. BKM120 combined with chloroquine, enhanced growth-inhibitory effects including induction of apoptosis, suggesting that autophagy is a protective mechanism counteracting BKM120s growth-inhibitory activity. Interestingly, BKM120 increased p-ERK1/2 levels. When blocking the activation of this signaling with MEK inhibitors or with knockdown of ERK1/2, the ability of BKM120 to increase LC3-II was attenuated and the growth-inhibitory effects including induction of apoptosis were accordingly enhanced, suggesting that the MEK/ERK activation contributes to BKM120-induced authophagy. In mouse xenograft model, we also found that the combination of BKM120 and PD0325901 synergistically suppressed cell growth in human lung cancer cells. Thus, the current study not only reveals mechanisms accounting for BKM120-induced autophagy, but also suggests an alternative method to enhance BKM120s therapeutic efficacy against non-small cell lung cancer(NSCLC) by blocking autophagy with either a lysosomal protease inhibitor or MEK inhibitor.

FOXP4 modulates tumor growth and independently associates with miR-138 in non-small cell lung cancer cells.

Family of forkhead box transcription factors, including forkhead box P4 (FOXP4), plays an important role in oncogenesis. The current study is to evaluate the role of FOXP4 in regulating human non-small cell lung cancer (NSCLC). Quantitative RT-PCR and Western blot were performed to evaluate the gene and protein expressions of FOXP4 in six NSCLC cell lines and 55 NSCLC patients. Lentivirus of small hairpin RNA (FOXP4-shRNA) was used to downregulate FOXP4 in NSCLC cell lines A549 and H1703 cells. Its effect on NSCLC growth, invasion, and cell cycle were evaluated by cell proliferation assay, migration assay, and cell cycle assay, respectively. Dual luciferase assay and Western blot were used to examine whether microRNA-138 (miR-138) was an upstream regulator of FOXP4. The dependence of FOXP4 on miR-138 associated signaling pathway was evaluated by ectopically overexpressing enhancer of zeste homolog 2 (EZH2), a known miR-138 target in NSCLC. FOXP4 was highly expressed in both NSCLC cell lines and NSCLC patients. FOXP4 downregulation by FOXP4-shRNA markedly reduced cancer cell growth and invasion, as well as induced cell cycle arrest in A549 and H1703 cells. MiR-138 was confirmed to be an upstream regulator of FOXP4 and directly regulated FOXP4 expression in A549 and H1703 cells. FOXP4 downregulation-mediated inhibition on cancer cell growth and invasion was independent on overexpressing EZH2, another direct target of miR-138 in NSCLC. Our data demonstrated that FOXP4 was a critical regulator in NSCLC and independently associated with miR-138 regulation.

Expression and clinicopathological significance of S100 calcium binding protein A2 in lung cancer patients of Chinese Han ethnicity

BACKGROUND S100 family of calcium-binding proteins plays a significant role in the process of many kinds of tumors, including lung cancer. As an important member of this family, S100 calcium binding protein A2 (S100A2) has been confirmed to be associated with many biological processes, and has an abnormal expression in non-small cell lung cancer (NSCLC). However, the S100A2 status in lung cancer is still controversial and undefined. METHODS We evaluated the pattern and distribution of S100A2 in 109 cases of lung cancer, including five histological types (47 adenocarcinoma, 46 squamous cell carcinoma, 7 small cell carcinoma, 3 large cell carcinoma, and 6 atypical carcinoid), and 30 cases of paired adjacent normal lung tissues by means of immunohistochemistry. RESULTS Compared with the normal tissues (0/30), S100A2 experienced a dramatically upward trend of positive expression in lung cancer, with a positive rate of 68/109 (P<0.001). Specifically, squamous cell carcinoma, with 34/12, had the highest expression ratio, followed by large cell carcinoma (2/1), adenocarcinoma (31/16), and atypical carcinoid (1/5) respectively, while no S100A2 protein was detected in small cell carcinoma. Meanwhile, we firstly demonstrated that the high expression of S100A2 was significantly associated with the incidence of lymph node metastasis in adenocarcinoma (P=0.013). CONCLUSIONS The association between high S100A2 expression and NSCLC at the level of tissue, and S100A2 may serve as an effective biomarker for the diagnosis and prognosis of NSCLC in future.

Atypical Presentation of Tracheobronchopathia Osteochondroplastica: Is Chronic Inflammation a Perpetrator?

Objective: To report an atypical presentation of tracheobronchopathia osteochondroplastica (TO). Clinical Presentation and Intervention: A 59-year-old man was investigated for productive cough of 1 month. An antimycobacterial combination regime was initiated with a misdiagnosis of endobronchial tuberculosis. At follow-up, the patient reported worsening of his symptoms. CT revealed an increased intensity of the cartilage ring surrounding the trachea, and bronchoscopy showed tracheal stenosis with white, hard nodules on the airway submucosa. Histopathology confirmed the diagnosis of TO. Conclusion: This case showed that TO should be considered in patients with cough not explained by noninvasive testing and not responsive to empiric medications.

Descriptive data on cancerous lung lesions detected by auto-fluorescence bronchoscope: A five-year study

BACKGROUND: Auto-fluorescence bronchoscopy (AFB) has been used for the identification and localization of intra-epithelial pre-neoplastic and neoplastic lesions within the bronchus. OBJECTIVES: To determine the applicability of AFB for the detection and localization of precancerous and cancerous lesions, in addition to analyzing the morphologic presentation, their association to histological type and the variation between genders. METHODS: A five-year study involving 4983 patients, who underwent routine bronchoscopy [B] examination in a local tertiary teaching hospital, was done. The B examination was performed under intratracheal lidocaine, and samples were obtained using suitable approach. One thousand four hundred and eighty-five pathologically confirmed lung cancer patients were included in the study. The following parameters were studied: Morphological presentation, biopsy sites, histology. Differences between the groups were analyzed using Chi square test. RESULT: One thousand four hundred and eighty-five patients who had hyperplasia or neoplastic lesions were further confirmed as lung cancer pathologically. Lung cancer was more commonly found in the right lung (51.58% vs. 42.82%). The lesion occurred more frequently in the upper lobe than the lower lobe (44.17% vs. 22.42%). Male patients with squamous cell carcinoma showed upper lobe involvement more commonly, while the left main bronchus was more commonly involved in female patients. Adenocarcinoma mostly involved lesion of the upper lobe. Squamous cell carcinoma and small cell carcinoma were the major proliferative types (80.15% and 76.16% respectively). CONCLUSION: AFB is efficient in the detection of pre-invasive and invasive lung lesions. The morphological presentation is associated to the histological type. There is variation in the presentation and histology of cancerous lung lesions between genders.

Polymorphisms in C-Reactive Protein and Glypican-5 Are Associated with Lung Cancer Risk and Gartrokine-1 Influences Cisplatin-Based Chemotherapy Response in a Chinese Han Population

The role of genetics in progression of cancer is an established fact, and susceptibility risk and difference in outcome to chemotherapy may be caused by the variation in low-penetrance alleles of risk genes. We selected seven genes (CRP, GPC5, ACTA2, AGPHD1, SEC14L5, RBMS3, and GKN1) that previously reported link to lung cancer (LC) and genotyped single nucleotide polymorphisms (SNPs) of these genes in a case-control study. A protective allele “C” was found in rs2808630 of the C-reactive protein (CRP). Model association analysis found genotypes “T/C” and “C/C” in the dominant model and genotype “T/C” in the overdominant model of rs2808630 associated with reduced LC risk. Gender-specific analysis in each model showed that genotypes “T/T” and “C/C” in rs2352028 of the Glypican 5 (GPC5) were associated with increased LC risk in males. Logistic regression analysis showed “C/T” genotype carriers of rs4254535 in the Gastrokine 1 (GKN1) had less likelihood to have chemotherapy response. Our results suggest a potential association between CRP and GPC5 variants with LC risk; variation in GKN1 is associated with chemotherapy response in the Chinese Han population.