Changes in tumor-antigen expression profile as human small-cell lung cancers progress

Objective

Our group has previously observed that in patients with small-cell lung cancers (SCLCs), the expression of a tumor antigen, glioma big potassium (gBK) ion channel, is higher at the time of death than when the cancer is first treated by surgical resection. This study aimed to determine whether this dichotomy was common in other potential lung tumor antigens by examining the same patient samples using our more extensive profile analysis of tumor-antigen precursor protein (TAPP). We then tested the hypothesis that therapeutic intervention may inadvertently cause this increased gBK production.

Methods

SCLC samples (eight surgical resections and three autopsy samples) and three control lungs were examined by quantitative real-time polymerase chain reaction for 42 potential TAPPs that represent potential T-cell-mediated immunological targets.

Results

Twenty-two TAPP mRNAs displayed the same profile as gBK, i.e., more mRNAs were expressed at autopsy than in their surgical counterparts. B-cyclin and mouse double minute 2, human homolog of P53-binding protein were elevated in both autopsy and surgical specimens above the normal-lung controls. When HTB119 cells were incubated with doxorubicin, gBK was strongly induced, as confirmed by intracellular flow cytometry with a gBK-specific antibody.

Conclusion

Our findings suggested that more immunological targets became available as the tumor responded to chemotherapy and proceeded toward its terminal stages.KEYWORDS : Small-cell lung cancer (SCLC), glioma big potassium (gBK) ion channel, tumor antigens, immunoprevention, real-time polymerase chain reaction, T-lymphocytes     

Second-line treatments of small-cell lung cancers

Introduction: Second-line therapies for relapsed small cell lung cancer (SCLC) patients remain a challenge, with limited clinical benefit because of rapid tumor growth, early dissemination and the development of drug resistance during the disease. Recent developments in genomic sequencing have provided further insight into the biology of the disease, identifying new targets and new pathways.

Areas covered: This review details chemotherapy, targeted therapies and immune-checkpoint blockades that have been investigated as second-line treatments for SCLC patients using a PubMed search (period 1990 – 2016, terms used: SCLC, treatments, second line, therapy).

Expert commentary: Recent genomic, proteomic and preclinical studies have identified novel therapeutic strategies currently being evaluated in clinical trials. Promising approaches for SCLC management include delta-like ligand-3 (DLL3)-targeted antibody–drug conjugate, combination targeted therapies, or targeted therapy–chemotherapy with an additive effect superior to the efficacy of single agents. The blockade of immune checkpoints has yielded promising preliminary results and is being investigated in ongoing trials. The inclusion of SCLC patients relapsing after platin-doublet induction in well-designed clinical trials remains a major challenge.     

CD44 expression in metastatic and non-metastatic non-small cell lung cancers

CD44 is an integral membrane glycoprotein that functions as a receptor for the extracellular matrix glycan, hyaluronan. It exists as standard (CD44s) and variant (CD44v) isoforms which have been shown to be associated with metastasis in a range of tumors. Both CD44s and CD44v are found in normal respiratory epithelium and in non small cell lung cancers (NSCLCs). However, there isn't much information regarding their role in the metastatic process of NSCLCs. We examined the expression of CD44s in 30 NSCLCs using immunohistochemical techniques. Ten were non-metastatic (N0, M0), 5 were metastases to lymph nodes (N1, M0) and 15 were excised brain metastases. We found CD44s positivity in all non-metastatic tumors with varying degrees of expression, whereas 10 out of 15 metastatic tumors in brain and 3 out of 5 lymph node metastases were negative for CD44s. There was a statistically significant inverse relation between the CD44s expression and metastatic potential (P < 0.05). Our results support the hypothesis that diminished or lack of CD44s is the functional equivalent of CD44v which may be an accompaniment of enhanced metastatic potential. The value of CD44 in predicting metastatic behavior of NSCLCs remains to be established in a larger series.     

Aberrant DNA methylation profiles of non-small cell lung cancers in a Korean population

We performed this study to investigate the aberrant methylation profile of the cancer-related genes in Korean non-small cell lung cancer (NSCLC) that previously exhibited high frequencies of methylation in Western populations. The aberrant promoter methylation of eight genes (GSTP1, p16, FHIT, APC, RASSF1A, hMLH1, hMSH2, AGT) was determined by MSP in 99 surgically resected NSCLCs and their corresponding nonmalignant lung tissues. Methylation in the tumor samples was detected at 15% for GSTP1, 22% for p16, 34% for FHIT1, 48% for APC, 40% for RASSF1A, 18% for hMLH1, 8% for hMSH2 and 21% for AGT, whereas it occurred at lower frequencies in the corresponding nonmalignant lung tissues, particularly in the p16 (1%) and RASSF1A (1%) genes. These results suggest that the methylation profiles of NSCLCs in a Korean population are similar to those in Western populations.     

Chromosomal aberrations and gene expression profiles in non-small cell lung cancer

Alterations in genomic content and changes in gene expression levels are central characteristics of tumors and pivotal to the tumorigenic process. We analyzed 23 non-small cell lung cancer (NSCLC) tumors by array comparative genomic hybridization (array CGH). Aberrant regions identified included well-characterized chromosomal aberrations such as amplifications of 3q and 8q and deletions of 3p21.31. Less frequently identified aberrations such as amplifications of 7q22.3-31.31 and 12p11.23-13.2, and previously unidentified aberrations such as deletion of 11q12.3-13.3 were also detected. To enhance our ability to identify key acting genes residing in these regions, we combined array CGH results with gene expression profiling performed on the same tumor samples. We identified a set of genes with concordant changes in DNA copy number and expression levels, i.e. overexpressed genes located in amplified regions and underexpressed genes located in deleted regions. This set included members of the Wnt/beta-catenin pathway, genes involved in DNA replication, and matrix metalloproteases (MMPs). Functional enrichment analysis of the genes both overexpressed and amplified revealed a significant enrichment for DNA replication and repair, and extracellular matrix component gene ontology annotations. We verified the changes in expressions of MCM2, MCM6, RUVBL1, MMP1, MMP12 by real-time quantitative PCR. Our results provide a high resolution map of copy number changes in non-small cell lung cancer. The joint analysis of array CGH and gene expression analysis highlights genes with concordant changes in expression and copy number that may be critical to lung cancer development and progression.     

非小细胞肺癌mRNA的表达谱分析

目的 检测非小细胞肺癌（NSCLC）组织和正常肺组织中mRNA的表达差异,并进行生物信息学分析。方法 采用基因芯片技术对3例NSCLC组织和3例正常肺组织的mRNA进行检测,筛选差异表达基因,进一步对差异表达基因进行Gene Ontoloty（GO）分析和信号通路分析。结果 在20 716条目的基因中共发现两种组织差异表达基因896条,其中593条基因表达增加,303条基因表达降低;生物信息学分析表明上述差异性表达的mRNA参与了NSCLC重要的生物学调节功能和通路。结论 基因芯片技术可以筛选出NSCLC组织和正常肺组织间差异表达的基因,mRNA在NSCLC组织和正常肺组织间的表达水平有明显差异,差异性表达的mRNA参与了NSCLC重要的生物学功能。     

Smac在非小细胞肺癌表达的临床意义

Objective  

The aim of our study was to investigate the clinical significance of Smac (second mitochondria-derived activator of caspase) expression on non-small cell lung cancer (NSCLC).     

Gene expression profiling of non-small cell lung cancer

Functional genomics has emerged over the past 10 years as a novel technology to study genetic alterations. Gene expression arrays are one genomic technique employed to discover changes in the DNA expression that occur in neoplastic transformation. Microarrays have been applied to investigating lung cancer. Specific applications include discovering novel genetic changes that occur in lung tumors. Microarrays can also be applied to improve diagnosis, staging and discover prognostic markers. The eventual goal of this technology is to discover new markers for therapy and to customize therapy based on an individual tumor genetic composition. In this review, we present the current state of gene expression array technology in its application to lung cancer.     

Metastases from fresh human non-small cell lung cancers propagated in nude mice.

Specimens from 69 freshly resected human non-small cell lung cancers (NSCLC) were transplanted into nude mice. Twelve mice died before the transplants were evaluable. There were 4 takes of 12 evaluable transplants into untreated athymic nude mice and 24 takes of 45 evaluable transplants into nude mice with decreased natural killer (NK) cell activity. Fourteen tumor lines were propagated into 2 or more successive transplant generations. Distant metastases occurred from the mid-dorsal transplant site in 8 of 81 (9.88%) recipients of 4 of those tumor lines, after 3-9 consecutive tumor growth cycles. Xenotransplantation of freshly resected human NSCLC provides a model with potential for serial assessment of cellular changes related to metastatic capability.     

Protein expression profiles indicative for drug resistance of non-small cell lung cancer

Data obtained from multiple sources indicate that no single mechanism can explain the resistance to chemotherapy exhibited by non-small cell lung carcinomas. The multi-factorial nature of drug resistance implies that the analysis of comprising expression profiles may predict drug resistance with higher accuracy than single gene or protein expression studies. Forty cellular parameters (drug resistance proteins, proliferative, apoptotic, and angiogenic factors, products of proto-oncogenes, and suppressor genes) were evaluated mainly by immunohistochemistry in specimens of primary non-small cell lung carcinoma of 94 patients and compared with the response of the tumours to doxorubicin in vitro. The protein expression profile of non-small cell lung carcinoma was determined by hierarchical cluster analysis and clustered image mapping. The cluster analysis revealed three different resistance profiles. The frequency of each profile was different (77, 14 and 9%, respectively). In the most frequent drug resistance profile, the resistance proteins P-glycoprotein/MDR1 (MDR1, ABCB1), thymidylate-synthetase, glutathione-S-transferase-pi, metallothionein, O6-methylguanine-DNA-methyltransferase and major vault protein/lung resistance-related protein were up-regulated. Microvessel density, the angiogenic factor vascular endothelial growth factor and its receptor FLT1, and ECGF1 as well were down-regulated. In addition, the proliferative factors proliferating cell nuclear antigen and cyclin A were reduced compared to the sensitive non-small cell lung carcinoma. In this resistance profile, FOS was up-regulated and NM23 down-regulated. In the second profile, only three resistance proteins were increased (glutathione-S-transferase-pi, O6-methylguanine-DNA-methyltransferase, major vault protein/lung resistance-related protein). The angiogenic factors were reduced. In the third profile, only five of the resistance factors were increased (MDR1, thymidylate-synthetase, glutathione-S-transferase-pi, O6-methylguanine-DNA-methyltransferase, major vault protein/lung resistance-related protein).     

CD133 expression: a potential prognostic marker for non-small cell lung cancers

Background

CD133 is a membrane glycoprotein containing five transmembrane loops. Previous reports suggest that a CD133-positive subpopulation of multipotent cells with extensive proliferative and self-renewal characteristics has biological features of a cancer stem cell. In addition, the presence of CD133-positive cells was associated with a significantly poorer prognosis for some solid tumors, compared to those with CD133-negative cells. However, the clinicopathological significance of CD133 in non-small cell lung cancer (NSCLC) remains controversial.

Methods

We conducted immunohistochemical assessment of 161 NSCLCs surgically resected at Hokkaido University Hospital between 1982 and 1994 to evaluate correlations between CD133 expression and various clinicopathological features.

Results

CD133 expression was significantly correlated with pathological stages (pStages) II, III, and IV for the various NSCLC types analyzed and was an independent factor for unfavorable prognosis in this population (hazard ratio = 3.157, P = 0.015).

Conclusion

CD133 expression was correlated with pStage and was predictive of unfavorable prognosis in patients with pStages II, III, and IV NSCLC. These results suggest the possibility of using CD133 as a novel prognostic marker in these patients.     

PTEN基因与恶性肿瘤

抑癌基因PTEN是双特异性磷酸脂酶，在多种恶性肿瘤中发生突变或缺失，导致其抑癌功能减弱或丧失，在多种恶性肿瘤的发生、发展中起重要作用。PTEN通过复杂的信号转导网络（PI3K／AKT、FAK／MAPK、PTEN／P53／MDM2）调控细胞周期、促进细胞凋亡、抑制肿瘤的血管形成和侵袭转移等。对PTEN基因的深入研究将为恶性肿瘤的早期诊断、临床监测、基因靶向治疗、预后评估、新药研发和一级预防提供科学的理论依据。     

PTEN基因与恶性肿瘤

抑癌基因PTEN是双特异性磷酸脂酶,在多种恶性肿瘤中发生突变或缺失,导致其抑癌功能减弱或丧失,在多种恶性肿瘤的发生、发展中起重要作用。PTEN通过复杂的信号转导网络(PI3K/ AKT、FAK/MAPK、PTEN/P53/MDM2)调控细胞周期、促进细胞凋亡、抑制肿瘤的血管形成和侵袭转移等。对PTEN基因的深入研究将为恶性肿瘤的早期诊断、临床监测、基因靶向治疗、预后评估、新药研发和一级预防提供科学的理论依据。