Lung cancer detection by a RT-nested PCR using MAGE A1--6 common primers

Detection of Circulating Gastrointestinal Cancer Cells in Conditionally Reprogrammed Cell Culture

BACKGROUND/AIM

The aim of this study was to detect circulating tumor cells (CTC) in the peripheral blood of gastrointestinal cancer patients using conditionally reprogrammed cell (CRC) culture.

MATERIALS AND METHODS

We confirmed the sensitivity of the CRC culture method. Five ml of blood were obtained from 81 cancer patients (56 colorectal and 25 gastric). The collected mononuclear cells were cultured for 4 weeks in the CRC condition. Finally, cultured cells were characterized by RT-PCR for the expression of hTERT and MAGE A1-6 mRNA.

RESULTS

The CRC method had a CTC detection limit of 6 cells for gastric cancer cells. After culture of 81 blood specimens, 38 formed visible cells, including 5 colonies. Among the 38 cells, 13 were hTERT positive and 4 were MAGE A1-6 positive. The final CTC detection rate was 16.0%.

CONCLUSION

The CRC culture may potentially be used to evaluate the metastatic cancer cells in the circulation.

Molecular approaches to lung cancer prevention

Lung cancer is generally diagnosed at advanced stages when surgical resection is not possible. Late diagnosis, along with development of chemoresistance, results in high mortality. Preventive approaches, including smoking cessation, chemoprevention and early detection are needed to improve survival. Smoking cessation combined with low-dose computed tomography screening has modestly improved survival. Chemoprevention has also shown some promise. Despite these successes, most lung cancer cases remain undetected until advanced stages. Additional early detection strategies may further improve survival and treatment outcome. Molecular alterations taking place during lung carcinogenesis have the potential to be used in early detection via noninvasive methods and may also serve as biomarkers for success of chemopreventive approaches. This review focuses on the utilization of molecular biomarkers to increase the efficacy of various preventive approaches.

The association of melanoma-associated antigen-A gene expression with clinicopathological characteristics and prognosis in resected non-small-cell lung cancer: a meta-analysis

Our goal was to explore the association of melanoma-associated antigen-A (MAGE-A) gene expression with clinicopathological parameters and survival rates in patients with non-small-cell lung cancer (NSCLC) who had surgery. A systematic search of EMBASE, PubMed, Web of Science and The Cochrane Library databases was performed through 20 April 2019. The combined risk ratios (RRs) and hazard ratios (HRs) with their corresponding 95% confidence intervals (CIs) were calculated to assess the association of MAGE-A gene expression with clinicopathological characteristics and prognosis of patients with resected NSCLC, respectively. All statistical analyses were performed with Stata software, version 12.0. A total of 9 articles involving 1538 patients were included in our meta-analysis; most of the studies were from Asian countries. The results indicated that the expression of the MAGE-A gene was significantly correlated with lymph node metastases (RR 1.21, 95% CI 1.09-1.34; P = 0.001), high tumour-node-metastasis stage (RR 1.24, 95% CI 1.12-1.38; P < 0.001), histological type (squamous cell carcinoma) (RR 1.82, 95% CI 1.15-2.87; P = 0.01), poor overall survival (HR 2.11, 95% CI 1.73-2.57; P < 0.001) and cancer-specific survival (HR 1.76, 95% CI 1.12-2.78; P = 0.015). MAGE-A gene expression is related to tumour development and metastasis and is more prevalent in squamous cell carcinomas of the lung; besides, it is an independent prognostic factor for patients with resected NSCLC.

Melanoma antigen-encoding gene family member A1-6 and hTERT in the detection of circulating tumor cells following CD45- depletion and RNA extraction

A total of 76 blood samples from patients without malignant disease and 107 blood samples from patients with malignant disease were investigated for the presence of circulating tumor cells (CTCs). To detect CTCs, hematopoietic cells were removed from the blood samples and different RNA extraction methods were used to amplify the melanoma antigen-encoding gene family member A1-family member A6 (MAGE A1-6) and the human telomerase reverse transcriptase (hTERT) gene as potential CTC markers. Comparison between four methods for extracting RNA from the blood was performed. The samples were enriched by cluster of differentiation 45 (CD45) antibody capturing, and the reverse transcription-quantitative polymerase chain reaction was used to amplify the MAGE A1-6 and hTERT genes. MAGE A1-6 and hTERT gene expression levels were also evaluated in 14 cancer cell lines, and the MAGE A1-6 and hTERT expression levels were 85.7 and 100%, respectively. The RNeasy method demonstrated the most sensitivity in the SNU1 cells mixed with blood, although the differences between methods was non-significant. The positive expression levels of MAGE A1-6 and hTERT was 11.8% in the control group and 58.9% in those with malignant disease. In the 70 patients with colorectal cancer, positive expression levels of MAGE A1-6 or hTERT were significantly higher in stages T3 and T4 compared with in stages T1 and T2. The CTC detection method involving CD45 antibody capture, RNA extraction and MAGE A1-6 and hTERT reverse transcription resulted in good rates of sensitivity and specificity. Thus, the present study concluded that MAGE A1-6 and hTERT genes may be potential and practical markers for CTCs in a clinical setting.

Association of MAGE A1-6 Expression with Lung Cancer Progression

The melanoma-associated antigen (MAGE) genes are known to be expressed in various kinds of tumors including lung cancer. Although they are studied as targets for immunotherapy and tools for early detection of lung cancer, the correlation between MAGE expression and the prognosis in lung cancer has not been clarified. In this study, we evaluated the relationship between MAGE A1-6 gene expression and the clinical prognosis in lung cancer. Bone marrow aspirations were performed in 60 patients who were diagnosed as lung cancer and underwent lung cancer surgery between 2007 and 2008. Each bone marrow was examined using nested reverse transcription- polymerase chain reaction (RT-PCR) with the MAGE common primer to detect MAGE A1-6. Overall survival rate, disease-free survival rate, recurrence, and distant metastasis were reviewed retrospectively. Survival periods were analyzed using SPSS ver. 20.0. Of the total 60 lung cancer patients, 9 patients (15%) had MAGE A1-6. MAGE A1-6-positive patients showed poor overall survival and overall disease-free survival rates (43.8 ± 26.1, 43.2 ± 26.9 months, respectively) compared with MAGE A1-6-negative patients (54.4 ± 17.2, 44.8 ± 22.1 months, respectively). No significant difference was shown in either survival rates. In conclusion, MAGE A1-6 expression of bone marrow in lung cancer patients correlated with poor survival rates. We suggest that MAGE A1-6 may be considered as a novel prognostic factor for lung cancer which leads to effective follow-up and treatment.

Overexpression of MAGEA2 has a prognostic significance and is a potential therapeutic target for patients with lung cancer

Melanoma-associated antigens (MAGE) are expressed in different type of cancers including lung cancer and have been shown to be functionally related to p53 tumor suppressor gene. Little is known about the relationship between MAGE genes and p53 aberrant expression in lung cancer. The aims of this study were to observe the expression of MAGEA2, examine the role of MAGEA2 in lung cancer survival, investigate its correlation between MAGEA2 and p53, and explore its clinicopathologic significance as a prognostic marker. Quantitative reverse transcription-polymerase chain reaction was performed to detect the expression of MAGEA2 using 36 primary tumors and 31 metastatic lymph nodes from patients with lung cancer. The role of MAGEA2 in cancer cell growth and in the regulation of p53 downstream genes were examined using small interfering RNA. The expression of MAGEA2 and p53 were analyzed immunohistochemically using tissue microarray from 353 resected lung specimens. High-level expression of MAGEA2 (High-MAGEA2) was confirmed in lung tumors with high frequency. Inhibiting MAGEA2 expression effectively suppressed cancer cell growth and decreased the expression of p53 downstream target genes in vitro. In adenocarcinoma, High-MAGEA2 was strongly associated with aberrant p53 expression (P<0.001) and was associated with worse clinical outcomes (5-year OS, 87.1% in low vs. 74.1% in high, P=0.014). Aberrant p53 expression was also significant worse prognostic factor (P=0.029). Among the adenocarcinoma patients with wild-type p53, High-MAGEA2 had poorer prognosis than low-level MAGEA2 groups (5-year OS, 90.1% vs. 72.1%, P=0.037), whereas had no difference in p53 aberrant tumors. On multivariate analysis, MAGEA2 was independently associated with survival (hazard ratio; 2.12, P=0.030). In conclusion, suppression of MAGEA2 in lung cancer cells significantly reduced the growth/survival of cancer cells. High-MAGEA2 was identified as an independent prognostic factor in lung adenocarcinoma. Specific inhibition of MAGEA2 may be a promising therapeutic strategy for patients with lung cancer.

MAGE-A1-6 expression in patients with head and neck squamous cell carcinoma: impact on clinical patterns and oncologic outcomes

BACKGROUND

Various subtypes of melanoma-associated antigens (MAGEs) are expressed in the tumor tissues of patients with head and neck squamous cell carcinoma (HNSCC). However, little data are currently available on how the gene expression of MAGEs impacts clinical patterns and oncologic outcomes. We have therefore evaluated the expression of MAGE-A1-6 (A1-6) subtypes in tumor tissues of patients with HNSCC and the clinical impact of this expression.

METHODS

This was a retrospective review of 53 patients with histologically proven HNSCC of the oral cavity, oropharynx, larynx, or hypopharynx who underwent both treatment and analysis by reverse transcription (RT)-PCR assay with a common primer to identify the expression of MAGE-A1-6 subtypes in the tumor tissue. The clinicopathologic factors and oncologic outcomes of these patients and the correlations of both to MAGE-A1-6 gene expression were analyzed.

RESULTS

MAGE-A1-6 subtypes were expressed in the tumor tissues of 37 patients (69.8 %). Patient age of ≥65 years [p = 0.031, hazard ratio (HR) 4.866] and advanced American Joint Committee on Cancer stage (p = 0.035, HR 4.291) were independent risk factors for expression of MAGE-A1-6 subtypes. Patients with MAGE-A1-6 expression had lower disease-free survival (p = 0.029), disease-specific survival (p = 0.070), and overall survival (p = 0.017) rates. Overall survival rate was independently associated to chemotherapy (p = 0.011, HR 2.859), while no surgery (p = 0.050, HR 2.400) and MAGE-A1-6 expression (p = 0.050, HR 2.527) showed borderline significance.

CONCLUSION

In our patient group the expression of MAGE-A1-6 subtypes in tumor tissues of patients with HNSCC was correlated with advanced clinical stage of cancer and poor oncologic outcomes. We suggest that gene expression of MAGE-A1-6 subtypes may be considered to be a predictive factor to determine patient treatment or follow-up strategy.

Clinical significance of melanoma-associated antigen A1-6 expression in sputum of patients with squamous cell carcinoma of the larynx and hypopharynx

BACKGROUND

Several studies have reported the expression of the melanoma-associated antigen (MAGE) gene in head and neck squamous cell carcinoma (HNSCC). In this study, we evaluated the correlations between MAGE expression in sputum and the clinical features and oncologic outcomes of SCC of the larynx and hypopharynx.

METHODS

We performed a retrospective review of 119 patients treated for SCC of the larynx and hypopharynx and analysis of their induced sputum by nested reverse transcription-polymerase chain reaction (RT-PCR) to detect the MAGE-A1-6 gene. The associations between MAGE expression and clinical characteristics were analyzed.

RESULTS

Expression of MAGE-A1-6 in sputum was identified in 57 of 119 patients (47.9%), and was independently correlated to double primary cancer (p = .024; odds ratio [OR] = 4.135). Expression of MAGE-A1-6 in sputum was correlated to poor survival.

CONCLUSION

Expression of MAGE-A1-6 in sputum predicts poor oncologic outcome in patients with SCC of the larynx and hypopharynx. © 2015 Wiley Periodicals, Inc. Head Neck 38: E736-E740, 2016.

Epidemiology of lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Ever since a lung cancer epidemic emerged in the mid-1900 s, the epidemiology of lung cancer has been intensively investigated to characterize its causes and patterns of occurrence. This report summarizes the key findings of this research.

METHODS

A detailed literature search provided the basis for a narrative review, identifying and summarizing key reports on population patterns and factors that affect lung cancer risk.

RESULTS

Established environmental risk factors for lung cancer include smoking cigarettes and other tobacco products and exposure to secondhand tobacco smoke, occupational lung carcinogens, radiation, and indoor and outdoor air pollution. Cigarette smoking is the predominant cause of lung cancer and the leading worldwide cause of cancer death. Smoking prevalence in developing nations has increased, starting new lung cancer epidemics in these nations. A positive family history and acquired lung disease are examples of host factors that are clinically useful risk indicators. Risk prediction models based on lung cancer risk factors have been developed, but further refinement is needed to provide clinically useful risk stratification. Promising biomarkers of lung cancer risk and early detection have been identified, but none are ready for broad clinical application.

CONCLUSIONS

Almost all lung cancer deaths are caused by cigarette smoking, underscoring the need for ongoing efforts at tobacco control throughout the world. Further research is needed into the reasons underlying lung cancer disparities, the causes of lung cancer in never smokers, the potential role of HIV in lung carcinogenesis, and the development of biomarkers.

Molecular sputum analysis for the diagnosis of lung cancer

Lung cancer is the leading cause of cancer mortality rate worldwide, mainly because of the presence of metastatic disease at the time of diagnosis. Early detection of lung cancer improves prognosis, and towards this end, large screening trials in high-risk individuals have been conducted since the past century. Despite all efforts, the need for novel (complementary) lung cancer diagnostic and screening methods still exists. In this review, we focus on the assessment of lung cancer-related biomarkers in sputum in the past decennium. Besides cytology, mutation and microRNA analysis, special attention has been paid to DNA promoter hypermethylation, of which all available literature is summarised without time restriction. A model is proposed to aid in the distinction between diagnostic and risk markers. Research on the use of sputum for non-invasive detection of early-stage lung cancer has brought new insights and advanced molecular techniques. The sputum shows a promising potential for routine diagnostic and possibly screening purposes.

The role of pleural fluid MAGE RT-nested PCR in the diagnosis of malignant pleural effusion

BACKGROUND

  Melanoma antigen (MAGE) genes are expressed in tumor cells, the testis and the placenta. The purpose of this prospective study was to investigate the sensitivity, specificity, and accuracy of the carcinoembryonic antigen (CEA), MAGE reverse transcriptase-nested polymerase chain reaction (RT-nested PCR), and cytology of pleural fluid in the diagnosis of malignant pleural effusion.

METHODS

  Patients in whom unilateral pleural effusion was identified on chest radiography from January to December 2009 were included in the study. MAGE genes were analyzed by RT-nested PCR using MAGE A1-6 common primers.

RESULTS

  Of 81 enrolled patients, 46 were diagnosed as malignant pleural effusion, and 24 were diagnosed as benign pleural effusion. The diagnoses of 11 patients were not confirmed in this study. The diagnostic sensitivity, specificity, and accuracy of MAGE RT-nested PCR were 61.4%, 95.7%, and 73.1%, respectively. The diagnostic sensitivities of cytology and CEA (>5 ng/mL) were 61.4% and 75.0%, respectively. Among 17 patients with negative cytology who had malignant pleural effusion, 12 and 10 patients were positive for CEA (>5.0 ng/mL) and MAGE RT-nested PCR, respectively. However, of five patients with malignant pleural effusion that was not recognized by cytology and CEA, MAGE RT-nested PCR correctly predicted a malignant etiology in only one additional patient (20%).

CONCLUSIONS

  MAGE RT-nested PCR seems to add little on the combination of conventional methods in the diagnosis of malignant effusion.

MAGE-4 gene m-RNA and TGF in blood as potential biochemical markers for HCC in HCV-infected patients

Progression from chronic hepatitis C virus infection to cirrhosis then to hepatocellular carcinoma usually results in some protein changes in peripheral blood. We evaluated MAGE-4 mRNA, TGFβ1 and AFP in peripheral blood as potential biochemical markers for diagnosis and prognosis of some complications of HCV infection. MAGE-4 mRNA in blood by reverse transcription polymerase chain reaction, serum TGF-Β1 and AFP by ELISA was assayed in seventy-five individuals who were classified into five groups: group I (control) comprised fifteen apparently healthy volunteers, group II involved fifteen HCV-infected patients without cirrhosis, group III involved fifteen HCV fifteen HCV-infected patients with cirrhosis, group IV included fifteen HCV-infected patients with cirrhosis and early stage HCC, and group V included fifteen HCV cirrhotic patients and late-stage HCC. We found that the frequency of positivity of MAGE-4 among the late hepatoma group was 40 %, while in the early hepatoma group the positivity was 6.7 %. The results for TGF-Β1 revealed a significant increase in serum TGF-Β1 in groups IV and V as compared to control, II, III groups. The obtained results of AFP showed a significant positive increase in serum AFP in groups IV and V when compared to groups II and III. Detection of MAGE-4 transcripts in blood, especially with follow-up survey, may help to predict the prognosis and monitoring of the response to the therapy, and serum TGF-Β1 level in HCC patients is directly correlated with metastasis and recurrence of tumors and increases gradually with the progression of HCC.

MAGE A1-A6 RT-PCR and MAGE A3 and p16 methylation analysis in induced sputum from patients with lung cancer and non-malignant lung diseases

The melanoma antigen gene (MAGE) A1-A6 RT-PCR system was developed for the detection of lung cancer cells in the sputum. However, we identified MAGE expression in some patients with non-malignant lung diseases. To understand these patterns of MAGE expression, we performed MAGE A3 methylation-specific PCR (MSP) and p16 MSP. We collected 24 biopsy specimens of lung cancer tissue and performed MAGE A1-A6 RT-PCR, MAGE A3 MSP and p16 MSP. RNA and DNA were simultaneously extracted from induced sputum specimens of 133 patients with lung diseases and 30 random sputum specimens of healthy individuals and the 3 molecular analyses were performed. The patients were diagnosed as 65 cases of lung cancer and 68 of benign lung diseases. Positive rates of MAGE A1-A6 RT-PCR, MAGE A3 MSP and p16 MSP were as follows: in lung cancer tissue, 87.5, 58.3 and 70.8%; in the sputum of lung cancer patients, 50.8, 46.2 and 63.1%; benign lung diseases, 10.3, 30.9 and 39.7%; and healthy individuals, 3.3, 6.7 and 3.3%. Of the 40 MAGE-positive cases, 33 were diagnosed with lung cancer and 7 as having benign lung diseases. From the 7 cases of MAGE-positive benign lung diseases, 6 cases showed methylation abnormalities. The MAGE-positive group revealed significantly higher rates of methylation abnormalities. Of the 40 MAGE-positive cases, 39 cases were found to be lung cancer or benign lung diseases with abnormal methylation. Thus, MAGE expression in the sputum suggests the presence of lung cancer cells or pre-cancerous cells.

Melanoma-associated antigen (MAGE) expression in the normal mucosa around colorectal cancer after curative resection: presence of undetectable free cancer cells

PURPOSE

Curative surgical resection is of great importance and some trials have been performed to identify free undetectable cancer cells using molecular markers. The aim of this study is to investigate melanoma-associated antigen (MAGE) expression in normal mucosa around colorectal cancer and its clinical significance.?

MATERIAL AND METHOD

From October 2003 to June 2004, we collected 46 colorectal cancer and matched normal mucosal tissues within 20 mm, 20 to 50 mm and more than 50 mm from tumors after the curative operation. Twenty-two mucosal tissues were harvested from patients with benign colorectal diseases as controls. MAGE expression was assayed using nested RT-PCR of MAGE A1-6 mRNA.?

RESULTS

The MAGE expression rates in cancer tissue and adjacent normal mucosa were 65.2%, 6.5% (<20 mm), 2.2% (20-50 mm) and 0.0% (>50 mm), respectively, while MAGE was not expressed in the mucosa of benign diseases. The MAGE-positive cases in the normal mucosa around tumors were located in the left colon or rectum, and one patient showed anastomotic mucosal site recurrence.?

CONCLUSIONS

MAGE expression in normal-appearing mucosa around colorectal cancer showed some clinical findings suggesting the presence of undetectable free cancer cells after curative resection.

Usefulness of melanoma antigen (MAGE) gene analysis in tissue samples from percutaneous needle aspiration biopsy of suspected lung cancer lesions

BACKGROUND

As mortality from lung cancer is still very high, early detection prior to metastasis is important in clinical settings. We prospectively evaluated the clinical usefulness of a reverse transcription-nested polymerase chain reaction (RT-nested PCR) using melanoma antigen (MAGE) A1-6 genes with tissue samples obtained from the percutaneous needle aspiration (PCNA) biopsies used in the diagnosis of lung cancer.

METHODS

We enrolled 53 patients with suspected lung cancer based on CT scan (M:F, 39:14; mean age 61 years). A PCNA biopsy was performed twice and lung cancer was diagnosed by a pathological examination. The MAGE genes were analyzed using RT-nested PCR from tissue samples obtained from the PCNA biopsy of the lesion. We compared the results from the RT-nested PCR and the pathologic diagnosis. We also analyzed the sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV).

RESULTS

Of the 53 patients, 39 were diagnosed with lung cancer. Six patients had tuberculosis and 8 were confirmed with chronic inflammation or benign lesion. Based on the RT-nested PCR examination, 41 of 53 patients were positive for the MAGE gene: 34 of 39 patients had lung cancer; 5 of 6 patients had tuberculosis; and 2 of 8 patients had chronic inflammation or benign lesion. The sensitivity, specificity, accuracy, PPV and NPV were 83%, 58%, 77%, 87% and 55%, respectively.

CONCLUSION

MAGE gene analysis by RT-nested PCR may be a useful method for the diagnosis of lung cancer, but it is still limited in patients with tuberculosis.

Expression of melanoma-antigen-A (MAGE-A) in disseminated tumor cells in regional lymph nodes of patients with operable non-small cell lung cancer

PURPOSE

Single disseminated tumor cells are detectable in regional lymph nodes of 30-50% patients with early-stage non-small cell lung cancer (NSCLC). This study investigated if these disseminated tumor cells express MAGE-A and thus might be targeted by adjuvant anti-MAGE-A immunotherapies.

EXPERIMENTAL DESIGN

Lymph nodes of 32 consecutive patients without neoadjuvant therapy were removed by systematic lymphadenectomy during resection of NSCLC. One-hundred of these lymph nodes were cut into two equal halves which were examined using either routine histo-pathology or quantitative reverse transcriptase PCR (qRT-PCR). qRT-PCR amplification of cytokeratin 19 transcripts was applied for the detection of disseminated tumor cells. Expression of MAGE-A was analyzed using one single primer pair amplifying subgroups MAGE-A1 to -A6 in one qRT-PCR reaction.

RESULTS

Ninety-four (94%) lymph nodes were tumor-free by histo-pathology. qRT-PCR detected disseminated tumor cells in 26 (28%) of these lymph nodes resulting in 19 (59%) patients with disseminated tumor cells. All of the remaining 6 lymph nodes that were judged by the pathologist to contain tumor cells exhibited CK19 transcripts. Fifteen (46%) lymph nodes with disseminated tumor cells contained MAGE-A transcripts resulting in 12 (37%) patients with disseminated tumor cells which expressed MAGE-A. There was no correlation between clinico-pathological parameters and the occurrence of disseminated tumor cells or their MAGE-A expression.

CONCLUSIONS

Since 37% of patients with operable NSCLC harbored disseminated tumor cells that expressed MAGE-A, only these patients might benefit from adjuvant immunotherapies directed against MAGE-A1 to -A6. This study may provide a basis for the preselection of patients to be included in such immunotherapy trials after resection of NSCLC.

The detection of peripheral lung cancer by MAGE A1-6 RT-nested PCR in bronchial washing specimens

BACKGROUND

With expansion of lung cancer screening by computed tomography (CT) and increased incidence of adenocarcinoma, we encountered more peripheral nodules to be identified. We evaluated detection rates of the melanoma antigen genes (MAGE) RT-nested PCR using a common MAGE A1-6 primer in bronchoscopic washing samples from patients with bronchoscopically invisible peripheral nodules, and compared with those of conventional cytology and percutaneous needle aspiration biopsy (PCNB).

MATERIALS AND METHODS

Forty-two patients with bronchoscopically invisible peripheral lung nodules were studied. Bronchoscopic washing specimens were collected by instilling 20ml of normal saline into a tumor bearing segment and retrieving samples. Samples were split and analyzed by MAGE RT-PCR and conventional cytology. A PCNB was performed in all but two patients. Twenty-eight lesions were diagnosed as lung cancers and 14 as benign lung diseases. We evaluated MAGE A1-6 RT-nested PCR, cytology, and PCNB results and analyzed them according to histologic cell types and tumor sizes.

RESULTS

In bronchial washing samples, the detection rates of MAGE A1-6 RT-nested PCR (67.9%) were higher than that of conventional cytology (21.4%, p=.04) and similar to that of PCNB (73.1%, p=.45) in 28 cancer patients. In terms of histologic types, the detection rates of MAGE A1-6 RT-nested PCR, conventional cytology, and PCNB were 78.6%, 21.4% and 64.3% in adenocarcinoma, 70%, 20% and 77.8% in squamous cell carcinoma, respectively. The sensitivity of conventional cytology was significantly lower than that of MAGE RT-nested PCR or PCNB regardless of tumor histology p=.04, p=.025, respectively, in adenocarcinoma; p=.035, p=.04, respectively, in squamous cell carcinoma). In terms of tumor size, the corresponding detection rates were 73.3%, 6.7% and 73.3% for tumors smaller than 3cm (N=15), and 61.5%, 38.5% and 72.7% for tumors larger than 3cm (N=13).

CONCLUSIONS

MAGE A1-6 RT-nested PCR showed higher detection rates in the bronchial washes of peripheral lung cancer patients than conventional cytology testing. This method is simple and robust, and it could be effectively utilized as a peripheral lung cancer detection tool in clinical laboratories.

Expression of melanoma-associated antigens in oral squamous cell carcinoma

BACKGROUND

Melanoma-associated antigens-A (MAGE-A) are expressed in a variety of tumors but not in normal tissues. Thus, their detection is highly specific to cancer cells, which makes them potential targets for the diagnosis, prognosis and also immunotherapy of neoplastic diseases.

METHODS

To determine the expression pattern and potential role of MAGE-A antigens in oral squamous cell carcinoma (OSCC), expression patterns of MAGE-A1-A6 and A12 were analyzed in 55 OSCC and 20 healthy oral mucosa using high-sensitive reverse transcription-nested polymerase chain reaction (RT-nPCR).

RESULTS

The 85.45% of tumor specimens expressed at least one of these genes. A significant correlation between the expression of MAGE-A1-A6 and A12 and malignancy was ascertained (P = 0.0001). On the contrary, none of the normal mucosal specimens expressed one of the MAGE-A subtypes. Antigen expression did not correlate with clinicopathological parameters, such as TNM classification, grading and clinical stage of OSCC.

CONCLUSIONS

Multiple simultaneous detection of MAGE-A1-A6 and A12 expression has been found to be more specific and sensitive than the detection of single MAGE-A antigen for the diagnostic and prognostic evaluation of OSCC. In addition, monitoring the expression of several MAGE-A subtypes may determine suitable immunotherapeutic targets. Subsequently, coexpressed genes may be warranted for developing polyvalent vaccines.

Detection of MAGE-A Transcripts in Bone Marrow Is an Independent Prognostic Factor in Operable Non–Small-Cell Lung Cancer

PURPOSE

MAGE-A gene expression in humans is mostly restricted to tumor cells, and the role of MAGE-A transcripts and peptides as diagnostic markers and therapeutic targets is currently under investigation. Thus far, the clinical relevance of MAGE-A transcripts as marker for disseminated tumor cells in bone marrow of patients with operable lung cancer without overt metastases is still unclear.

EXPERIMENTAL DESIGN

Preoperative bone marrow aspirates from 50 consecutive patients with operable non-small-cell lung cancer free of distant metastases (i.e., pT(1-4) pN(0-2) M(0) R(0)) were admitted to the study. Each bone marrow sample was divided and examined using multimarker MAGE-A reverse transcription-PCR (RT-PCR) and immunocytochemical staining with the anti-pancytokeratin antibody A45-B/B3. Multimarker MAGE-A RT-PCR consisted of multiple subtype-specific nested RT-PCRs with primers for MAGE-A1, MAGE-A2, MAGE-A3/6, MAGE-A4, and MAGE-A12. The median follow-up duration was 92 months (range, 18-110 months).

RESULTS

Twenty-six (52%) lung cancer patients harbored MAGE-A transcripts in their bone marrow, as opposed to none of the 30 healthy controls tested. In all 7 patients with immunocytochemically positive bone marrow, MAGE-A transcripts were also detected. All different MAGE-A subtypes (MAGE-A1, MAGE-A2, MAGE-A3/6, MAGE-A4, and MAGE-A12) were observed. Sixty-five percent of patients with MAGE-A transcripts in bone marrow exhibited only one subtype. Univariate (P = 0.03, log-rank-test) and multivariate survival analysis showed that MAGE-A transcripts in bone marrow were associated with poor outcome in pN(0) patients (P = 0.02; relative risk, 7.6).

CONCLUSIONS

Detection of MAGE-A transcripts in bone marrow predicts an unfavorable outcome in patients with early-stage operable lung cancer. This finding indicates that MAGE-A transcripts are clinically relevant markers of micrometastatic spread in lung cancer and supports further investigation of MAGE-A as potential future therapeutic target.

Detection of lung cancer using MAGE A1-6 and SSX4 RT-PCR expression profiles in the bronchial wash fluid

PURPOSE

Bronchial wash fluid may be a useful for detecting lung cancer. To increase the detection rates, we performed molecular analysis with using MAGE A1-6 and SSX4 RT-PCR on bronchial wash fluid specimens.

MATERIALS AND METHODS

We obtained 57 lung cancer tissue specimens by bronchoscopic biopsy and 131 bronchial washes from 96 patients with lung cancer and 35 patients with benign lung diseases. The MAGE A1-6 and SSX4 gene expressions were investigated in the cancer tissue specimens and bronchial wash fluids. We evaluated the positive detection rates of these methods according to the cytology results and the clinical findings.

RESULTS

For the cancer tissue specimens and the bronchial wash fluid, the positive detection rate of MAGE or SSX4 was 91.2% and 75.0%, respectively. Combined MAGE and SSX4 PCR and cytology tests showed an 83.3% detection rate for the bronchial wash fluid. From bronchial washes of patients with benign lung diseases, the positive rates of using MAGE or SSX4 was 11.4%. In the bronchial wash fluid of lung cancer patients, 66.7% of the peripheral cancers were detected by MAGE or SSX4, while examination with cytology did not detect any peripheral lung cancer.

CONCLUSION

The application of both MAGE and SSX4 showed high sensitivity and specificity for the detection of lung cancer. Thus, MAGE and SSX4 RT-PCR may be effectively utilized as additional methods to improve detection of lung cancer with using bronchial wash fluids.

Cell-free DNA concentration in pleural fluid and serum: quantitative approach and potential prognostic factor in patients with cancer and pleural effusions

PURPOSE

The presence of pleural effusions in patients with tumors is often indicative of locally advanced or metastatic disease, and detection of malignancy in effusion samples frequently leads to a disease upstaging. Our purpose was to quantify the DNA in pleural effusion and serum in patients presenting pleural effusion in order to assess the potential prognostic impact.

PATIENTS AND METHODS

The DNA level was determined by amplifying hRNase P in paired samples of serum and pleural fluid in 70 consecutive patients with cancer showing pleural effusion. A group of 30 patients without cancer was included. The correlation between serum and pleural DNA was calculated. Survival curves according to serum and pleural DNA were analyzed.

RESULTS

Median DNA concentrations were greater in patients with neoplasia than in patients without malignancy: 105 ng/mL versus 40 ng/mL (P = 0.001) in serum samples, respectively; 93 ng/mL versus 21 ng/mL (P = 0.001) in pleural fluids, respectively. A positive correlation between serum and pleural levels was confirmed (r = 0.3; P < 0.05). Median survival time for patients with serum DNA < or = 105 ng/mL was 11.03 months in contrast to only 3.63 months for patients with higher values (P = 0.036). Accordingly, median survival time for patients with pleural DNA < or = 93 ng/mL was 12.3 months versus only 4.63 months in case of higher levels (P = 0.027).

CONCLUSION

This study shows that there is a strong correlation between higher levels of free DNA in pleural fluid or serum and malignancy. Survival is worse for patients with higher DNA levels in serum and pleural fluid.

Differential expression profile of MAGE family in non-small-cell lung cancer

The expression of the melanoma-associated antigen (MAGE) genes consists of variables in all tumor types, such as lung cancer, which are relevant to be silent in all normal tissues except germ cells. They are considered as tumor-specific antigens, and are ideal targets for cancer immunotherapy. A complete MAGE genes differential expression profile analysis of lung cancer can provide this study not only various target genes for immunotherapy, but also valuable markers for further diagnosis and prognosis. This research has constructed a membrane array, which was consisted 32 MAGE genes, to detect whether the differential expression profile occurred in 52 pairs of non-small-cell lung cancer (NSCLC) samples. Nearly 32 MAGE genes have been differential expressed in NSCLC except MAGE-B1 and -E2. MAGE-B, -C, -D, and subgroup -B6, -D4 have showed prominences in lung adenocarcinoma. High-frequent expression of MAGE-D, and subgroup -A2, -D2 has also been discovered in non-metastasis group (p<0.05). However, there is no significant difference of MAGE genes differential expression shown among different primary tumor (T), nodal involvement (N) and overall stages. Several MAGE subgroup genes, such as MAGE-A5, -A7, -A8, -A9, -A11, -B3, -B4, -B10, -D2, -D3, -F1, -G1, -H1, and -L2, have been first discovered to show differential expression in NSCLC. Although the small size of the sample may limit the diagnostic and prognostic value of MAGE genes, the function of the membrane array can provide this study a high-throughput method to detect the whole MAGE genes differential expression profile.

The melanoma antigen gene as a surveillance marker for the detection of circulating tumor cells in patients with breast carcinoma

BACKGROUND

Circulating occult tumors cells could be used for the surveillance of metastases after primary breast carcinoma therapy, but their detection is limited by the lack of specific molecular markers. Melanoma antigen genes (MAGEs), which are expressed in malignant tissues but not in normal tissues (except for placenta and testis), might provide such a marker. To date, however, the use of MAGEs in the detection of occult tumor cells using reverse transcription-polymerase chain reaction (RT-PCR) has been limited because of the heterogeneity and low expression of individual MAGEs in tumor tissues.

METHODS

We developed multiple MAGE-recognizing primers (MMRPs) that were capable of binding to the cyclic DNA of 6 MAGE-A gene subtypes (MAGE-A1-MAGE-A6). We assessed the ability of the MMRPs to detect the expression of MAGE-A gene subtypes in peripheral blood obtained from patients with benign or malignant breast disease.

RESULTS

MAGE-A gene expression was not detected in 32 patients with benign disease but was detected in 1 of 31 patients (3%) patients with negative lymph node breast carcinoma, in 10 of 52 patients (19%) with 1-3 positive lymph nodes, in 11 of 53 patients (21%) with > or = 4 positive lymph nodes, and in 20 of 52 patients (39%) with metastatic disease. The results were statistically significant (P < 0.0001; chi-square test for linear-by-linear association). The results also showed that the detection of MAGE-A gene expression in the blood predicted tumor progression or recurrence.

CONCLUSIONS

The results suggested that MAGE-A gene expression may be used for the surveillance of circulating breast carcinoma cells after primary therapy by RT-nested PCR using MMRPs.

Gene-environment interaction signatures by quantitative mRNA profiling in exfoliated buccal mucosal cells

Exfoliated cytologic specimens from mouth (buccal) epithelium may contain viable cells, permitting assay of gene expression for direct and noninvasive measurement of gene-environment interactions, such as for inhalation (e.g., tobacco smoke) exposures. We determined specific mRNA levels in exfoliated buccal cells collected by cytologic brush, using a recently developed RNA-specific real-time quantitative reverse transcription-PCR strategy. In a pilot study, metabolic activity of exfoliated buccal cells was verified by 3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazolium assay in vitro. Transcriptional activity was observed, after timed in vivo exposure to mainstream tobacco smoke resulted in induction of CYP1B1 in serially collected buccal samples from the one subject examined. For a set of 11 subjects, mRNA expression of nine genes encoding carcinogen- and oxidant-metabolizing enzymes qualitatively detected in buccal cells was then shown to correlate with that in laser-microdissected lung from the same individuals (Chi2 = 52.91, P < 0.001). Finally, quantitative real-time reverse transcription-PCR assays for seven target gene (AhR, CYP1A1, CYP1B1, GSTM1, GSTM3, GSTP1, and GSTT1) and three reference gene [glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin, and 36B4] transcripts were performed on buccal specimens from 42 subjects. In multivariate analyses, gender, tobacco smoke exposure, and other factors were associated with the level of expression of CYP1B1, GSTP1, and other transcripts on a gene-specific basis, but substantial interindividual variability in mRNA expression remained unexplained. Within the power limits of this pilot study, gene expression signature was not clearly predictive of lung cancer case or control status. This noninvasive and quantitative method may be incorporated into high-throughput human applications for probing gene-environment interactions associated with cancer.

Molecular oncology — perspectives in lung cancer

Despite novel therapies in lung cancer treatment the 5-year survival rate still remains poor. Furthermore, screening concepts for early diagnosis, based on conventional sputum cytology and chest radiography, have so far not demonstrated an impact on decreasing lung-cancer mortality. More specific molecular markers allow new insights in the process of lung carcinogenesis. Furthermore they raise the hope that they provide new tools for early diagnosis and screening of high-risk individuals, determination of prognosis, and identification of innovative treatments. In this review, these perspectives of molecular targets in lung cancer will be discussed and summarised. Angiogenesis-stimulating factors (VEGF, FGF, MMP, etc.), parameters concerning tumour cell proliferation and apoptosis (EGFR, p53, K-ras, rb, bcl-2, etc.) are well known. Several of these genetic factors have already been investigated, but no single parameter has yet gained a sufficient selectivity regarding prognostic significance or therapeutic efficacy. New aspects in the complex tumour-stroma interaction and the interactive, cross-talking signal transduction pathways and recently developed functional genomic approaches, such as DNA microarrays and proteomics might lead to further progress in biological staging models and treatment concepts.