Recent advances in the molecular diagnosis of lung cancer

p53-inducible gene 3 promotes cell migration and invasion by activating the FAK/Src pathway in lung adenocarcinoma

The p53-inducible gene 3 (PIG3) is one of the p53-induced genes at the onset of apoptosis, which plays an important role in cell apoptosis and DNA damage response. Our previous study reported an oncogenic role of PIG3 associated with tumor progression and metastasis in non-small cell lung cancer (NSCLC). In this study, we further analyzed PIG3 mRNA expression in 504 lung adenocarcinoma (LUAD) and 501 lung squamous cell carcinoma (LUSC) tissues from The Cancer Genome Atlas database and we found that PIG3 expression was significantly higher in LUAD with lymph node metastasis than those without, while no difference was observed between samples with and without lymph node metastasis in LUSC. Gain and loss of function experiments were performed to confirm the metastatic role of PIG3 in vitro and to explore the mechanism involved in its oncogenic role in NSCLC metastasis. The results showed that PIG3 knockdown significantly inhibited the migration and invasion ability of NSCLC cells, and decreased paxillin, phospho-focal adhesion kinase (FAK) and phospho-Src kinase expression, while its overexpression resulted in the opposite effects. Blocking FAK with its inhibitor reverses PIG3 overexpression-induced cell motility in NSCLC cells, indicating that PIG3 increased cell metastasis through the FAK/Src/paxillin pathway. Furthermore, PIG3 silencing sensitized NSCLC cells to FAK inhibitor. In conclusion, our data revealed a role for PIG3 in inducing LUAD metastasis, and its role as a new FAK regulator, suggesting that it could be considered as a novel prognostic biomarker or therapeutic target in the treatment of LUAD metastasis.

Bitter gourd (Momordica charantia) as a rich source of bioactive components to combat cancer naturally: Are we on the right track to fully unlock its potential as inhibitor of deregulated signaling pathways

Research over decades has progressively explored pharmacological actions of bitter gourd (Momordica charantia). Biologically and pharmacologically active molecules isolated from M. charantia have shown significant anti-cancer activity in cancer cell lines and xenografted mice. In this review spotlight was set on the bioactive compounds isolated from M. charantia that effectively inhibited cancer development and progression via regulation of protein network in cancer cells. We summarize most recent high-quality research work in cancer cell lines and xenografted mice related to tumor suppressive role-play of M. charantia and its bioactive compounds. Although M. charantia mediated health promoting, anti-diabetic, hepatoprotective, anti-inflammatory effects have been extensively investigated, there is insufficient information related to regulation of signaling networks by bioactive molecules obtained from M. charantia in different cancers. M. charantia has been shown to modulate AKT/mTOR/p70S6K signaling, p38MAPK-MAPKAPK-2/HSP-27 pathway, cell cycle regulatory proteins and apoptosis-associated proteins in different cancers. However, still there are visible knowledge gaps related to the drug targets in different cancers because we have not yet developed comprehensive understanding of the M. charantia mediated regulation of signal transduction pathways. To explore these questions, experimental platforms are needed that can prove to be helpful in getting a step closer to personalized medicine.

Cell cycle-related and expression-elevated protein in tumor overexpression is associated with proliferation behaviors and poor prognosis in non-small-cell lung cancer

The cell cycle‐related and expression‐elevated protein in tumor (CREPT) is overexpressed in several human malignancies. However, the clinical relevance of CREPT expression and its biological role in non‐small‐cell lung cancer (NSCLC) remains unclear. In this study, we detected the expression of CREPT in both NSCLC tissues and cell lines by immunohistochemistry, Western blot analysis, and RT‐PCR. The correlation between CREPT expression and clinicopathologic features was analyzed in 271 NSCLC patients. The prognostic value of CREPT expression was evaluated by Kaplan–Meier analysis and Cox regression analysis. CREPT was overexpressed in Calu‐1 cell lines by using plasmid vector and its biological function was explored both in vitro and in vivo. We found that CREPT was significantly overexpressed in NSCLC compared with paired adjacent non‐tumor tissues, and the expression level of CREPT was correlated with tumor differentiation, lymph node metastasis, and clinical stage. Kaplan–Meier analysis showed that the recurrence‐free survival and overall survival of high CREPT expression groups were significantly shorter than those of the low CREPT expression group. Multivariate analysis identified that CREPT might be an independent biomarker for the prediction of NSCLC prognosis. Overexpression of CREPT increased cell proliferation and enhanced the migration and invasion ability of Calu‐1 cells (a human NSCLC cell line with relative low CRPET expression) in vitro. Moreover, CREPT overexpression promoted tumor growth in a nude mice model. These results suggest that CREPT is closely relevant to the proliferation of NSCLC cells and it might be a potential prognostic marker in NSCLC patients.

PIG3 promotes NSCLC cell mitotic progression and is associated with poor prognosis of NSCLC patients

Background

Non-small cell lung cancer (NSCLC) is the most commonly diagnosed type of lung cancer that is associated with poor prognosis. In this study we explored the potential role of p53-induced gene 3 (PIG3) in the progression of NSCLC.

Methods

Immunohistochemistry was used to determine the expression levels of PIG3 in 201 NSCLC patients. We performed in vitro studies and silenced endogenous PIG3 by using specific siRNAs that specific target PIG3. Immunofluorescent staining was performed to determine the effect of PIG3 on mitotic progression in NSCLC cells. The growth rates of microtubules were determined by microtubule nucleation analysis. Cell proliferation and chemosensitivity were analyzed by CCK8 assays. Annexin V staining and β-galactosidase activity analysis were used to evaluate PIG3 deficiency-related apoptosis and senescence, respectively.

Results

PIG3 expression levels negatively correlated with overall survival and disease-free survival of NSCLC patients. Knock down of PIG3 resulted in repressed proliferation of NSCLC cells and increased aberrant mitosis, which included misaligning and lagging chromosomes, and bi- or multi-nucleated giant cells. In addition, PIG3 contributed to mitotic spindle assembly by promoting microtubule growth. Furthermore, loss of PIG3 sensitized NSCLC cells to docetaxel by enhancing docetaxel-induced apoptosis and senescence.

Conclusions

Our results indicate that PIG3 promotes NSCLC progression and therefore suggest that PIG3 may be a potential prognostic biomarker and novel therapeutic target for the treatment of NSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0508-2) contains supplementary material, which is available to authorized users.

Pemetrexed and bevacizumab-containing chemotherapy for pleomorphic carcinoma of the lung

Pleomorphic carcinoma of the lung is a rare, highly malignant subtype of lung cancer, with a more aggressive clinical course compared with other types of non-small-cell lung cancer (NSCLC). Pemetrexed and bevacizumab are currently evaluated as two of the most reliable chemotherapeutic drugs for advanced NSCLC. We herein report a case of a 68- and a 46-year-old man with recurrent and chemo-naïve pleomorphic carcinoma of the lung, respectively, who were treated with a combination of carboplatin, pemetrexed and bevacizumab. The overall survival after the initiation of chemotherapy was 30 and 8 months, respectively. These cases exhibited a relatively long-term survival with chemotherapy. In the absence of definitive clinical trials, which are unlikely to be performed due to the rarity of this tumor, our cases demonstrated the potential utility of pemetrexed- and bevacizumab-containing chemotherapy. Our results also suggested that pemetrexed-containing chemotherapy may be key to the treatment of pleomorphic carcinoma of the lung.

Azacytidine inhibits the proliferation of human promyelocytic leukemia cells (HL60) by demethylation of MGMT, DAPK and p16 genes

BACKGROUND

Azacytidine (Aza) was the first demethylation agent identified that may inhibit DNA methyltransferases and reverse DNA hypermethylation, restoring the expression of silenced tumor suppressor genes in patients with myelodysplastic syndromes (MDS). It is unclear whether azacytidine can alter the proliferative and apoptotic changes in myeloid leukemia cells, and methylation changes induced by this drug have remained poorly characterized in therapy-related models.

METHODS

The proliferation rate of azacytidine on HL60 cells was determined by the MTT protocol. Methylation-specific PCR (MSP) and RT-PCR were used respectively to detect gene methylation status changes and expression levels of p16, Death associated protein kinase (DAPK) and O(6)-methylguanine-DNA methyltransferase (MGMT) before and after treatment with azacytidine.

RESULTS

Azacytidine inhibited HL60 cell proliferation and showed a time- and dose-dependent effect. MSP showed hypermethylated p16, DAPK, and MGMT genes before azacytidine treatment. Complete demethylation was seen in p16 and DAPK genes and partial demethylation in the MGMT gene after co-culture with azacytidine. The expression level of p16, DAPK and MGMT genes in HL60 cells was up-regulated after treatment with azacytidine.

CONCLUSIONS

The CpG islands of p16, DAPK and MGMT genes are hypermethylated in HL60 cells. Azacytidine inhibits proliferation of leukemic cells by hypomethylation of p16, DAPK and MGMT genes.

Molecular recognition of small-cell lung cancer cells using aptamers

Early diagnosis is the way to improve the rate of lung cancer survival, but is almost impossible today due to the lack of molecular probes that recognize lung cancer cells sensitively and selectively. We developed a new aptamer approach for the recognition of specific small-cell lung cancer (SCLC) cell-surface molecular markers. Our approach relies on cell-based systematic evolution of ligands by exponential enrichment (cell-SELEX) to evolve aptamers for whole live cells that express a variety of surface markers representing molecular differences among cancer cells. When applied to different lung cancer cells including those from patient samples, these aptamers bind to SCLC cells with high affinity and specificity in various assay formats. When conjugated with magnetic and fluorescent nanoparticles, the aptamer nanoconjugates could effectively extract SCLC cells from mixed cell media for isolation, enrichment, and sensitive detection. These studies demonstrate the potential of the aptamer approach for early lung cancer detection.

Polymorphisms in the epidermal growth factor receptor gene and the risk of primary lung cancer: a case-control study

BACKGROUND

Polymorphisms in Epidermal Growth Factor Receptor (EGFR) gene may influence EGFR production and/or activity, thereby modulating susceptibility to lung cancer. To test this hypothesis, we investigated the association between polymorphisms in the EGFR gene and the risk of lung cancer in a Korean population.

METHODS

We first examined the frequencies of 39 candidate polymorphisms in the EGFR gene in 27 healthy Korean individuals. After then, we genotyped five polymorphisms (127378C>T, 142285G>A, 162093G>A, 181946C>T and 187114T>C) that have variant allele frequencies greater than 10%, in 582 lung cancer patients and in 582 healthy controls.

RESULTS

Of the 5 polymorphisms, the 181946C>T genotype distribution was significantly different between the cases and controls (P = 0.04). Compared with the 181946 CC + CT genotype, the 181946 TT genotype was associated with a significantly decreased risk of lung cancer (adjusted OR = 0.63, 95% CI = 0.45-0.88, P = 0.007). When the analyses were stratified by smoking status, the protective effect of the TT genotype was statistically significant in ever-smokers (adjusted OR = 0.59, 95% CI = 0.41-0.86, P = 0.007), but not in never-smokers (adjusted OR = 0.89, 95% CI = 0.45-1.75, P = 0.73; P = 0.08, test for homogeneity). Consistent with the results of the genotyping analysis, the CGGCT haplotype with the 181946C allele was associated with a significantly increased risk of lung cancer compared to the CGGTT haplotype carrying the 181946T allele (adjusted OR = 1.50, 95% CI = 1.09-2.07, P = 0.012 and Bonferroni corrected P-value = 0.048).

CONCLUSION

These results suggest that the EGFR polymorphisms, particularly the 181945C>T polymorphism, could be used as markers for the genetic susceptibility to lung cancer.

Role of pemetrexed in non-small cell lung cancer

Pemetrexed was approved for the treatment of relapsed or chemotherapy refractory non-small cell lung cancer patients, as it produced similar response and survival outcomes and less toxicity as compared to taxotere. Pemetrexed in combination with platinum analogs or with gemcitabine or vinorelbine, produce equivalent responses and overall survival results compared to combinations of platinum analogs with other drugs. The role of bevacizumab and the inhibitors of epithelial growth factor receptor also should be evaluated in selected patients with NSCLC treated with pemetrexed combinations. Further increases in drug dose may be possible using transfer of drug resistance genes in hematopoietic stem cells.

The use of real-time polymerase chain reaction in thoracic malignancies

Recent progress in the molecular analysis of NSCLC tumors and lymph node status will likely translate into a clearer understanding of the variables and predictors of tumor recurrence. This understanding may lead to more appropriate therapeutic decisions both in the operating room and in the clinic. With these analyses at the molecular level, a more precise molecular classification is on the horizon which includes a molecular substaging. All of these aspects of NSCLC biology await testing or final analysis of prospective multi-institutional trials such as that set forth in CALGB 9761.

Molecular Diagnostic Markers for Lung Cancer in Sputum and Plasma

Lung cancer is the leading cause of cancer deaths worldwide. This study was designed to select multiple DNA markers, which have high sensitivity and specificity to serve as biomarkers for diagnosis of lung cancer. We examined the promoter hypermethylation of three tumor suppressor genes by methylation-specific PCR (MSP), and the instability of eight microsatellite markers by loss of heterozygosity (LOH) and microsatellite instability (MSI) analyses in lung tumor tissues and matched sputum specimens from 79 lung cancer patients. On the basis of the results of sensitivity, specificity, and concordance from each marker analyzed, we selected seven biomarkers, which are LOH of D9S286, D9S942, GATA49D12, and D13S170, MSI of D9S942, and methylation of p16(INK4a) and RARbeta, from the sputum analyses. These selected etiologically associated biomarkers can potentially be used as supplemental diagnostic biomarkers for early lung cancer detection.

Past, present and future of gene expression-tailored therapy for lung cancer

“Variability is the law of life, and as no two faces are the same, so no two bodies are alike, and no two individuals react alike and behave alike under the abnormal conditions which we know as disease.” Sir William Osler (1849–1919). All human beings are different and some of these differences are the variations in response to xenobiotics. Personalized medicine means: the right patient population, the right drug, the right dose, the right indication, and administration at the right time. This review provides an update on concepts of personalized therapy for lung cancer.

Promoter methylation of p16INK4a, RASSF1A, and DAPK is frequent in salivary adenoid cystic carcinoma

BACKGROUND

Promoter methylation is a common mechanism of inactivation of tumor suppressor genes in multiple tumor types. However, little is known about its role in the development of adenoid cystic carcinoma of the salivary gland (ACC). In the current study, the authors investigated whether promoter methylation is common in ACC and whether it may influence ACC development.

METHODS

The promoter methylation status of the genes p16(INK4a), RASSF1A, DAPK, and MGMT, which are important in cell growth regulation, apoptosis, and DNA repair, was determined in tissue sections of tumor samples from 60 patients with ACC using methylation-specific polymerase chain reaction. The association between methylation status and patients' clinical and pathologic characteristics were assessed.

RESULTS

Of the 60 tumors, DNA methylation of the p16(INK4a) promoter was detected in 28 tumors (47%); the respective values DNA methylation of the RASSF1A, DAPK, and MGMT promoters were 25 tumors (42%), 16 tumors (27%), and 4 tumors (7%), respectively. Forty-six tumors (77%) had DNA methylation in > or = 1 of the 4 promoters, 20 tumors (33%) had DNA methylation in > or = 2 promoters, 6 tumors (10%) had DNA methylation in > or = 3 promoters, and 1 tumor (2%) had DNA methylation in all 4 promoters. RASSF1A promoter methylation was more frequent in high-grade tumors than in low-grade tumors (P = 0.009), in advanced-stage tumors (P = 0.008), and in tumors with metastasis (P = 0.005).

CONCLUSIONS

Promoter methylation of p16(INK4a), RASSF1A, and DAPK was common in ACC, and it is possible that such methylation may influence the development of ACC. The high frequency of RASSF1A promoter methylation in high-grade tumors and in tumors with metastasis suggested a role for this gene in the progression of ACC.

Mouse models for human lung cancer

In recent years several new mouse models for lung cancer have been described. These include models for both non-small-cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). Tumorigenesis in these conditional mouse tumor models can be initiated in adult mice through Cre-recombinase-induced activation of oncogenic mutations in a subset of the cells. They present a marked improvement over mouse models that depend on carcinogen induction of tumors. These models permit us to study the consecutive steps involved in initiation and progression and allow us to address questions like the cell of origin, and the role of cancer stem cells in the maintenance of these tumors. They now need to be validated as suitable preclinical models for intervention studies in which questions with respect to therapy response and resistance can be addressed.

Versican in nonsmall cell lung cancer: relation to hyaluronan, clinicopathologic factors, and prognosis

The aim of the study was to investigate the expression and prognostic role of versican in 212 patients with resected nonsmall cell lung cancer. Tumor samples were stained immunohistochemically, and the versican staining was evaluated both in tumor stroma and cancer cells. The staining results were compared to the clinical data of the patients, the tumor cell proliferation, and the expression of hyaluronan. In the whole material, low and high area percentages of stromal versican staining were observed in 135 and 77 carcinomas, respectively. Tumor cell-associated staining signal for versican was observed in 33 cases. In the whole material, the significant relationship between high stromal staining of versican and that of hyaluronan was noticed (P = .001). The expression of stromal versican was related to tumor type (P = .008) and high stromal staining was inversely correlated with poor tumor differentiation (P = .045), but not with tumor cell proliferation. Among adenocarcinomas, the high stromal staining of versican was associated with tumor recurrence (P = .024), higher tumor stage (P = .022), and lymph node metastases (P = .042). Versican expression was not related to patient outcome in the whole material, but among adenocarcinomas, the high stromal staining was related to poor disease-free survival (P = .0056). However, in Cox multivariate analysis with tumor stage, versican expression did not retain its prognostic significance. The results indicate that increased stromal versican is related to higher tumor recurrence rate and more advanced disease. Despite the important role of versican in nonsmall cell lung cancer, traditional clinicopathologic factors remained most significant in the current study.

Overexpression of S100A2 protein as a prognostic marker for patients with stage I non small cell lung cancer

S100A2, a calcium-binding protein, recently became of major interest because of its differential expression during transformation and metastasis in various tumors. The purpose of this study was to investigate the prognostic significance of S100A2 expression in the early-stage non small lung cancer (NSCLC). Immunohistochemical analysis to determine the percentage of cells staining positive for S100A2 was performed on 11 NSCLC tissue microarray slides containing samples from 113 patients with pathologic stage I NSCLC who had undergone curative surgery. S100A2 was expressed in samples from 79 patients (69.9%). Kaplan-Meier analysis showed that patients whose tumors had positive S100A2 expression had a significantly lower overall survival and disease-specific survival rate at 5 years after surgery than did patients with negative S100A2 expression (p < 0.001 and p < 0.001, respectively). Age at diagnosis, histologic type of cancer, degree of differentiation and smoking history did not have a statistically significant effect on survival. Multivariate analysis confirmed that S100A2 expression is a better predictor for disease-specific survival than were other clinical and histologic variables tested. Our results suggested that the expression of the S100A2 protein in stage I NSCLC indicates poor prognosis and may be used to identify patients with early-stage NSCLC who might benefit from adjuvant treatment.

The biology of non-small-cell lung cancer: identifying new targets for rational therapy

Lung cancer, and in particular non-small-cell lung cancer (NSCLC), remains the leading cause of cancer death throughout the world. Almost three decades ago, the major concern was to identify whether cisplatin or cisplatin-based chemotherapy enhanced survival in metastatic NSCLC, and whether any survival benefit compensated for cisplatin-related toxicity. Over the last 10 years, significant advances have been achieved in molecular biology, including the identification of critical genes related to the pathogenesis of NSCLC, which have formed the basis for new targeted therapeutic approaches. These new approaches include novel agents against established chemotherapeutic targets such as thymidylate synthetase as well as agents that inhibit novel targets such as growth factor receptors and proteins important in angiogenesis. With the advent of genomic technologies that can identify patterns of gene expression, the hope is that therapy will be tailored to the genetic pattern of the patients's tumor, and individualized treatments that minimize toxicity and maximize efficacy can be developed.