The E-cadherin cell-cell adhesion complex and lung cancer invasion, metastasis, and prognosis

Epithelial cell adhesion molecule (KSA) expression: pathobiology and its role as an independent predictor of survival in renal cell carcinoma

PURPOSE

Epithelial cell adhesion molecule (EpCAM) is a widely expressed adhesion molecule in epithelial cancers. The purpose of this study is to determine the protein expression patterns of EpCAM in renal cell carcinoma (RCC) using tissue arrays linked to a clinicopathological database to evaluate both its predictive power in patient stratification and its suitability as a potential target for immunotherapeutic treatment strategies.

EXPERIMENTAL DESIGN

The University of California, Los Angeles kidney cancer tissue microarray contains specimens from 417 patients treated with nephrectomy. EpCAM protein expression in tumors and matched morphologically normal renal tissues was evaluated using anti-EpCAM immunohistochemistry. The resultant expression reactivity was correlated with clinicopathological variables.

RESULTS

EpCAM is consistently expressed in the distal nephron on normal renal epithelium. Clear cell RCCs show minimal and infrequent EpCAM expression, whereas chromophobe and collecting duct RCCs both demonstrate intense and frequent expression. Of 318 clear cell carcinomas used in the analysis, 10% were EpCAM positive in > or = 50% of cells, and 8% of patients would be considered candidates for EpCAM-based therapy, based on high expression [> or = moderate intensity and frequent (> or = 50%) expression] and the need for systemic treatment. EpCAM expression was an independent prognostic factor for improved disease-specific survival, with a multivariate hazard ratio of 0.63 (P = 0.017; 95% confidence interval, 0.43-0.92).

CONCLUSIONS

EpCAM is a novel prognostic molecular marker in RCC patients, and its positive expression is an independent predictor associated with improved survival. However, high expression in morphologically normal renal tissues and minimal or absent expression in clear cell carcinomas will likely limit the utility of this epithelial marker in targeted treatments of this most common RCC type.

DNA methylation in prostate cancer

Prostate cancer is the most common malignancy and the second leading cause of cancer death among men in the United States. There are three well-established risk factors for prostate cancer: age, race and family history. The molecular bases for these risk factors are unclear; however, they may be influenced by epigenetic events. Epigenetic events covalently modify chromatin and alter gene expression. Methylation of cytosine residues within CpG islands on gene promoters is a primary epigenetic event that acts to suppress gene expression. In tumorigenesis, the normal functioning of the epigenetic-regulatory system is disrupted leading to inappropriate CpG island hypermethylation and aberrant expression of a battery of genes involved in critical cellular processes. Cancer-dependent epigenetic regulation of genes involved in DNA damage repair, hormone response, cell cycle control and tumor-cell adhesion/metastasis can contribute significantly to tumor initiation, progression and metastasis and, thereby, increase prostate cancer susceptibility and risk. In this review, we will discuss current research on genes that are hypermethylated in human prostate cancer. We will also discuss the potential involvement of DNA methylation in age-related, race-related and hereditary prostate cancer, and the potential use of hypermethylated genes as biomarkers to detect prostate cancer and assess its risk.

E-cadherin-beta-catenin adhesion complex in neuroendocrine tumors of the lung: a suggested role upon local invasion and metastasis

Dysfunction or loss of the intercellular adhesion complex E-cadherin-beta-catenin is frequent in non-small cell lung carcinomas in which E-cadherin and beta-catenin loss has been considered to be a molecular marker of tumor progression and poor prognosis. With an aim of evaluating the expression of the E-cadherin-beta-catenin complex and its prognostic role in neuroendocrine tumors (NET) of the lung, immunohistochemical analysis was performed in 102 NET, including 16 low-grade typical carcinoids, 8 intermediate-grade atypical carcinoids, 37 large-cell neuroendocrine carcinomas (LCNEC), and 41 small-cell lung carcinomas, both high-grade tumors. Impaired E-cadherin expression (loss or cytoplasmic delocalization) was observed in 80 (78%) of 102 samples, and impaired beta-catenin expression was noted in 74 (72%) of 102 cases. The impaired expression of E-cadherin and beta-catenin was observed with a higher frequency in high-grade tumors (87% and 83%, respectively) than in carcinoids (50% and 37%, respectively; P < 0.0001). Impaired expression of the E-cadherin and beta-catenin molecules also correlated with lymph node metastasis (P = 0.0001 and P = 0.0005, respectively) and with advanced stage disease (P < 0.0001 for both factors). Moreover, impaired E-cadherin expression directly correlated with an extensive disease in carcinoids and in LCNEC (P = 0.02 and P = 0.04, respectively) and with node metastasis in LCNEC (P = 0.01). Levels of E-cadherin and beta-catenin were correlated with each other, consistent with an internal regulatory loop. Our results indicate that down-regulation of the E-cadherin-beta-catenin complex plays a role in NET progression.

Immunohistochemical patterns for alpha- and beta-catenin, E- and N-cadherin expression in ovarian epithelial tumors

OBJECTIVES

This study aims were to analyze and compare the E- and N-cadherin, beta- and alpha-catenin expression in benign and malignant epithelial neoplasms of the ovary, correlating with tumor staging, histological grade, and presence of metastases during evolution.

METHODS

Immunohistochemical reactions were performed on paraffin-embedded tissues and evaluated according to the number of positive, stained cellular structures and reaction intensity for each molecule. Information about histological type and grade, tumoral stage, and disease evolution was obtained from the patients' clinical records.

RESULTS

Most of the carcinomas showed more intense beta-catenin reaction (P = 0.02). More than 50% of the endometrioid carcinomas showed increased beta-catenin expression, with a large number of positive cells and more intense staining, being the same also observed for most of the serous benign tumors (P < 0.01). E-cadherin membrane expression was frequently observed in carcinomas without metastasis, whereas cases with metastases in evolution were negative or showing E-cadherin expression only in the cytoplasm (P = 0.04). N-cadherin expression differed according to histological type and grade and alpha-catenin was also related to histological type, but these findings were not conclusive.

CONCLUSIONS

Increased beta-catenin expression was more frequent in ovarian carcinomas, especially, but not only, in the endometrioid ones. The maintenance of E-cadherin expression in cellular membrane may be an independent marker of good prognosis in ovarian cancer. New studies about N-cadherin and alpha-catenin and their importance during ovarian carcinogenesis will be required.

Prognostic significance of E-cadherin protein expression in pathological stage I-III endometrial cancer

PURPOSE

Decreased expression of E-cadherin in endometrial cancer cells is associated with adverse prognostic features. This study aimed to evaluate the prognostic significance of decreased E-cadherin expression in patients with endometrial cancer.

EXPERIMENTAL DESIGN

Between 1992 and 1999, 102 endometrial cancer patients with stage I-III disease underwent primary surgery at the University of Chicago. Representative tissue specimens were immunostained with a monoclonal antibody to E-cadherin. A semiquantitative evaluation scale was developed based on the percentage of endometrial cancer cells with membranous E-cadherin staining. Tissue sections were scored as "3" if >75%, "2" if 25-75%, "1" if 5-25%, and "0" if <5% of cells stained. E-Cadherin staining was correlated with overall survival (OS), cause-specific survival (CSS), progression-free survival (PFS), and extrapelvic progression. Multivariate Cox proportional hazards modeling was used to estimate hazard ratios, controlling for clinicopathological characteristics and adjuvant treatment. Median follow-up for the study group was 58.5 months.

RESULTS

E-Cadherin staining was scored as 0, 1, 2, and 3 in 29.4%, 18.6%, 26.5%, 25.5% of cases, respectively. E-Cadherin expression was positively correlated with myometrial invasion (Kendall tau: 0.30, P < 0.01), and negatively correlated with grade (Kendall tau: -0.13, P = 0.15) and papillary serous or clear cell histology (Kendall tau: -0.14, P = 0.12). Five-year actuarial OS, CSS, PFS, and extrapelvic recurrence rates for negative (score = 0), heterogeneous (score = 1-2), and positive (score = 3) staining were as follows: OS, 69.2 versus 75.7 versus 81.0% (P = 0.64); CSS, 78.8 versus 91.2 versus 95.5% (P = 0.19); PFS, 69.1 versus 88.6 versus 92.2% (P = 0.079), and extrapelvic progression, 20.8 versus 7.3 versus 4.0% (P = 0.17). On multivariate Cox regression, a higher E-cadherin expression score was associated with decreased overall mortality [hazard ratio (HR), 0.59; 95% confidence interval (CI), 0.34-1.03; P = 0.066), and statistically significant decreases in endometrial cancer mortality (HR, 0.23; 95% CI, 0.055-0.94; P = 0.040), disease progression (HR, 0.28; 95% CI, 0.10-0.77; P = 0.014), and extrapelvic recurrence (HR, 0.24; 95% CI, 0.062-0.97; P = 0.045).

CONCLUSIONS

Decreased E-cadherin expression is an independent prognostic factor for disease progression and mortality in pathological stage I-III endometrial cancer. Evaluation of E-cadherin expression may aid in the selection of patients for more aggressive adjuvant therapy.

Altered expression of adhesion molecules and epithelial-mesenchymal transition in silica-induced rat lung carcinogenesis

Loss of the epithelial phenotype and disruption of adhesion molecules is a hallmark in the epithelial-mesenchymal transition (EMT) reported in several types of cancer. Most of the studies about the relevance of adhesion and junction molecules in lung cancer have been performed using established tumors or in vitro models. The sequential molecular events leading to EMT during lung cancer progression are still not well understood. We have used a rat model for multistep lung carcinogenesis to study the status of adherens and tight junction proteins and mesenchymal markers during EMT. After silica-induced chronic inflammation, rats sequentially develop epithelial hyperplasia, preneoplastic lesions, and tumors such as adenocarcinomas and squamous cell carcinomas. In comparison with normal and hyperplastic bronchiolar epithelium and with hyperplastic alveolar type II cells, the expression levels of E-cadherin, alpha-catenin and beta-catenin were significantly reduced in adenomatoid preneoplastic lesions and in late tumors. The loss of E-cadherin in tumors was associated with its promoter hypermethylation. alpha- and beta-catenin dysregulation lead to cytoplasmic accumulation in some carcinomas. No nuclear beta-catenin localization was found at any stage of any preneoplastic or neoplastic lesion. Zonula occludens protein-1 was markedly decreased in 66% of adenocarcinomas and in 100% squamous cell carcinomas. The mesenchymal-associated proteins N-cadherin and vimentin were analyzed as markers for EMT. N-cadherin was de novo expressed in 32% of adenocarcinomas and 33% of squamous cell carcinomas. Vimentin-positive tumor cells were found in 35% of adenocarcinomas and 88% of squamous cell carcinomas. Mesenchymal markers were absent in precursor lesions, both hyperplastic and adenomatoid. The present results show that silica-induced rat lung carcinogenesis is a good model to study EMT in vivo, and also provide in vivo evidence suggesting that the changes in cell-cell adhesion molecules are an early event in lung carcinogenesis, while EMT occurs at a later stage.

DNA-methylation analysis identifies the E-cadherin gene as a potential marker of disease progression in patients with monoclonal gammopathies

BACKGROUND

Silencing of tumor suppressor genes (TSG) by aberrant methylation (referred to as methylation) contributes to the pathogenesis of various human malignancies. However, little is known about the methylation of known and putative TSGs in monoclonal gammopathies. Thus, the authors investigated the methylation frequencies of 10 genes in patients with monoclonal gammopathies.

METHODS

The methylation patterns of the genes p16(INK4a) (p16), tissue inhibitor of metalloproteinase 3 (TIMP3), p15(INK4b) (p15), E-cadherin (ECAD), death-associated protein kinase (DAPK), p73, RAS-association domain family 1A (RASSF1A), p14, O(6)-methylguanine DNA methyltransferase (MGMT), and retinoid acid receptor beta2 (RARbeta) were determined in patients with monoclonal gammopathy of undetermined significance (MGUS; n = 29), smoldering multiple myeloma (SMM; n = 5), multiple myeloma (MM; n = 113), or plasma cell leukemia (PCL; n = 7) by methylation-specific polymerase chain reaction analysis.

RESULTS

Methylation frequencies for p16, TIMP3, p15, ECAD, DAPK, p73, RASSF1A, p14, MGMT, and RARbeta were as follows: 28%, 35%, 10%, 0%, 17%, 21%, 14%, 14%, 7%, and 0%, respectively, in patients with MGUS and 36%, 29%, 27%, 27%, 22%, 15%, 15%, 9%, 4%, and 0%, respectively, in patients with MM. Methylation of at least 1 of these genes was detected in 79% of patients with MGUS and in 80% of patients with MM. Although methylation of ECAD was not detected in patients with MGUS, it was observed frequently in patients with MM and with even greater frequency in patients with PCL. It is noteworthy that an association was found between ECAD methylation and poor prognostic markers in patients with MM.

CONCLUSIONS

Methylation of certain genes can be detected frequently in patients with monoclonal gammopathies. The current data suggest that methylation of ECAD is a marker of disease progression in patients with MM and PCL.

Molecular classification and molecular genetics of human lung cancers

Recent advances in the molecular classification of lung carcinomas and the identification of causative genetic alterations will likely lead to improvements in the diagnosis and treatment of patients with lung cancer. It is now possible to identify gene expression profiles that associate with patient outcome in lung carcinomas, in particular adenocarcinoma. Furthermore, patient survival has been shown to correlate with lung cancer oligonucleotide microarray expression profiles. Large-scale microarray technology may allow for the identification of useful biomarkers for early cancer detection. Oligonucleotide microarray data can be optimized by relating them to protein expression levels in tissue microarrays, by annotation with mutational data, and with results of testing for post-translational modification of cellular proteins. These data may be useful in tailoring chemotherapeutic protocols to individual tumors and identifying new targets for therapeutic intervention.

A different pattern of cytotoxic T lymphocyte recognition against primary and metastatic tumor cells in a patient with nonsmall cell lung carcinoma

BACKGROUND

Lung carcinoma represents the most frequent cause of cancer death worldwide because of tumor metastases. The objective of the current study was to analyze the immunologic response during the progress of lung carcinoma metastasis.

METHODS

The authors established two tumor cell lines that were derived from primary and metastatic lesions in a patient with lung carcinoma (Patient G603). One cell line (G603L) was established from the primary lesion, and the other cell line (G603AD) was established from a metastatic lesion in the right adrenal gland 7 months after the patient underwent surgery for the primary lesion. Autologous regional lymph node lymphocytes were stimulated with CD80-transfected G603L cells, then cytotoxic T lymphocytes (CTLs) were induced against both lung carcinoma cell lines.

RESULTS

Both G603L cells and G603AD cells expressed Class I human leukocyte antigen, intracellular cell adhesion molecule 1, and lymphocyte-associated antigen type 3 (LFA-3), but not Fas or Fas ligand on their surfaces. By stimulation with CD80-transfected G603L cells, 2 CTL clones (H2/17 and H2/36) were established from the bulk CTLs. CTL clone H2/17 lysed G603L cells but not G603AD cells, suggesting that the antigen recognized by CTL clone H2/17 was abrogated during the process of metastasis. In contrast, CTL clone H2/36 lysed both G603L cells and G603AD cells, indicating that the antigen recognized by CTL clone H2/36 was maintained in the tumor cells throughout tumor progression.

CONCLUSIONS

The results demonstrated the possibility that some tumor-associated antigens may be abrogated during the process of metastasis, although others are maintained. The identification of these antigens will lead to a better understanding of their immunologic role during disease progression in patients with lung carcinoma.

Independent value of fascin immunoreactivity for predicting lymph node metastases in typical and atypical pulmonary carcinoids

Immunoreactivity for fascin, an actin-bundling protein related to cell motility, has been reported in breast, ovary, pancreas, skin, and non-small cell carcinomas, and associated with more advanced disease stage and poorer prognosis. Data on pulmonary neuroendocrine (NE) tumors, however, are lacking. We evaluated the expression of fascin by immunohistochemistry--using two different monoclonal antibodies--in surgical specimens of pulmonary NE tumors of all the diverse histological types from 128 consecutive patients recruited between 1987 and 2001, and investigated its relationship with the presence of lymph node metastases. Overall, fascin immunoreactivity was detected in 5% of 38 typical carcinoids (TC), 35% of 23 atypical carcinoids (AC), 83% of 40 large-cell neuroendocrine carcinomas (LCNEC), and 100% of 27 small-cell lung carcinomas (SCLC) (P<0.001), Normal NE cells or hyperplastic NE tumorlets were consistently unreactive. No statistically significant differences in fascin immunoreactivity were found between the two antibodies. In TC and AC but not high-grade NE tumors, fascin immunoreactivity closely correlated with the occurrence of lymph node metastases, the pN class and the number of involved lymph nodes (P<0.001). It was also significantly associated with an increased proliferative activity (Ki-67 labeling index >5%) (P=0.020), and with either down-regulation or altered subcellular compartmentalization of E-cadherin (P<0.001) and CD99 (P=0.030), two cell adhesion complexes in pulmonary NE tumors. At multivariate analysis, only fascin emerged as an independent predictor of lymph node metastases in this tumor group (HR 30.28; 95% confidence intervals: 1.59-574.49; P=0.023). This study indicates that fascin immunoreactivity may identify subsets of pulmonary carcinoid patients with different metastatic potential to regional lymph nodes. Targeting the fascin pathway could be a novel therapeutic strategy of pulmonary carcinoids.

Epidermal growth factor family of receptors in preneoplasia and lung cancer: perspectives for targeted therapies

The Erb-B family of receptors plays an important role in lung carcinogenesis and tumor development, and EGFR and HER2 are highly expressed in bronchial preneoplasia. In invasive tumors, EGFR are expressed in 50-90%, and mostly in squamous cell carcinomas, but also in adenocarcinomas and large cell carcinomas, while HER2 is less frequently expressed (20-30%) and mostly expressed in adenocarcinomas. Bronchioloalveolar cell carcinomas may present a distinct EGFR profile compared to the other NSCLCs and evidence and consequences are discussed. The genetic mechanisms responsible for overexpression of EGFR and HER2 proteins might be numerous, including gene dosage (overrepresentation or amplification) as well as translational and post-translational mechanisms. However, for EGFR and HER2 there is a positive correlation between gene copy numbers and level of protein expression demonstrated by fluorescence in situ hybridization analysis and immunochemistry. Gene amplification for EGFR and HER2 is demonstrated in only 5-10% of the tumors. The treatment status and therapeutic limitation with trastuzumab (Herceptin) in lung cancer compared to breast cancer is discussed.

E-Cadherin mediates MMP down-regulation in highly invasive bronchial tumor cells

The disorganization of E-cadherin/catenin complexes and the overexpression of matrix metalloproteinases (MMPs) are frequently involved in the capacity of epithelial cells to acquire an invasive phenotype. The functional link between E-cadherin and MMPs was studied by transfecting invasive bronchial BZR tumor cells with human E-cadherin cDNA. Using different in vitro (cell dispersion, modified Boyden chamber) and in vivo assays (human airway epithelial xenograft), we showed that E-cadherin-positive clones displayed a decrease of invasive abilities. As shown by immunoprecipitation, the re-expressed E-cadherin was able to sequestrate one part of free cytoplasmic beta-catenin in BZR cells. The decrease of beta-catenin transcriptional activity in E-cadherin-transfected clones was demonstrated using the TOP-FLASH reporter construct. Finally, we observed a decrease of MMP-1, MMP-3, MMP-9, and MT1-MMP, both at the mRNA and at the protein levels, in E-cadherin-positive clones whereas no changes in MMP-2, TIMP-1, or TIMP-2 were observed when compared with control clones. Moreover, zymography analysis revealed a loss of MMP-2 activation ability in E-cadherin-positive clones treated with the concanavalin A lectin. These data demonstrate a direct role of E-cadherin/catenin complex organization in the regulation of MMPs and suggest an implication of this regulation in the expression of an invasive phenotype by bronchial tumor cells.

The basement membrane matrix in malignancy

Cancer is the second most common cause of death among Americans, although for several age groups it ranks first. Most of these deaths are not due to the primary tumour but rather to tumour cell metastases to distant organs. There are many steps that lead to metastasis, all of which are being studied with the goal of preventing these fatalities. Normally, cells attach to the extracellular matrix to maintain tissue integrity. During cancer progression, cells become more motile and acquire invasive qualities. Tumour cells move along blood and lymph vessels or invade into them to travel to distant sites. Then, the tumour cells must attach to the vessel wall, extravasate from the vessel, invade the new tissue, proliferate, and form a secondary tumour. Angiogenesis, the formation of new blood vessels, is critical to survival of these cells at the new site and is also important for primary tumour growth and spread. Tumour cell metastasis is a complex cascade of sequential steps, each of which is not yet fully understood. Progress has been made in identifying several key activators, one of which is the extracellular matrix. A major tumour promoter is the glycoprotein laminin, which is predominantly found in the extracellular matrix produced by endothelial and epithelial cells. This review will follow the metastatic process with particular attention to the effect of laminin on tumour cells.

Relationship between expression of E-cadherin-catenin complex and clinicopathologic characteristics of pancreatic cancer

AIM: To investigate the expression of E-cadherin and alpha-catenin and beta-catenin in pancreatic carcinoma and its relationship with the clinicopathologic characteristics, and clarify the mechanism of invasion and metastasis of pancreatic cancer.

METHODS: The expression of E-cadherin and alpha-, beta-catenin was examined in 47 cases of infiltrative ductal adenocarcinoma of pancreas and 12 adult normal pancreatic tissues by immunohistochemical technique.

RESULTS: The immunoreactivity of E-cadherin and alpha-, beta-catenin was expressed by normal ductal and acinar cells with strong membranous staining at the intercellular border in 12 cases of adult normal pancreatic tissues. Abnormal expression of E-cadherin and alpha-, beta-catenin in 47 pancreatic carcinoma tissues was demonstrated in 53.2%, 61.7% and 68.1%, respectively. Both abnormal expression of E-cadherin and alpha-catenin significantly correlated with differentiation, lymph node and liver metastases (P < 0.05, respectively), whereas aberrant beta-catenin expression only correlated with lymph node and liver metastases (P < 0.001). Abnormal E-cadherin and alpha-, beta-catenin expression was not associated with tumor size, invasion and survival time of patients (P > 0.05, all).

CONCLUSION: Pancreatic cancer likely occurs in case of E-cadherin-catenin complex genes mutations or deletions and abnormal expression of proteins, which significantly correlate with the biologic character of the tumor and lymph node and liver metastases. It is suggested that the abnormal E-cadherin-catenin complex expression plays an important role in the development and progression of tumor, and thus may become a new marker in pancreatic cancer metastasis.

DC-CLM, a cadherin-like molecule cloned from human dendritic cells, inhibits growth of breast cancer cells

PURPOSE

To identify the characteristics and function of a cadherin-like molecule, cloned from a human dendritic cell (DC) cDNA library and designated DC-derived cadherin-like molecule (DC-CLM).

METHODS

The mRNA expression of DC-CLM in tissues and cells was analyzed by Northern blot and RT-PCR, respectively. In order to express DC-CLM in target cells, we constructed a pcDNA3.1/DC-CLM expression vector and transfected it into MCF-7 human breast cancer cells. Tumor growth was demonstrated by cell proliferation and colony formation.

RESULTS

DC-CLM cDNA encoded a protein of 260 amino acids and the gene was localized to chromosome 5q31. The predicted protein possessed a definitive cadherin-specific sequence motif and shared homology with classical cadherin. However, no transmembrane segment was observed in DC-CLM. Northern blot revealed the ubiquitous nature of DC-CLM transcripts in human tissues, with high expression in heart, brain, prostate, testis and ovary. RT-PCR demonstrated that DC-CLM was widely expressed in hematopoietic and epithelial tumor cell lines, but was not expressed in MCF-7. Interestingly, DC-CLM expression was upregulated in DC activated by lipopolysaccharides. DC-CLM expression in the stable transfectant (MCF-7/DC-CLM) was confirmed by RT-PCR and Western blot. DC-CLM protein was found to be secreted by MCF-7/DC-CLM but not expressed on the membrane of MCF-7/DC-CLM. DC-CLM transfection resulted in significant inhibition of in vitro growth and colony formation of MCF-7 cells.

CONCLUSIONS

A cadherin-like molecule DC-CLM was cloned from human DC and it may be a soluble cadherin-like molecule for tumor suppression. DC-CLM was upregulated in activated DC and may be involved in the effector function of activated DC.

Detection of oncogenes in the diagnosis of cancers with active oncogenic signaling

Releasing individuals from susceptibility to and anxiety about the development of cancer is an eventual goal of cancer research. This owes much to rapid progress in molecular oncology that is supported by advances in technology. Cancers of the colon and rectum, pancreas and lung that share certain clinical and molecular oncological characteristics represent timely and important target of this field. Of the genes altered in these types of cancers, the best documented is K-ras. Currently highlighted along with this oncogene is beta-catenin, which has roles in both cell adhesion and transformation. Molecular diagnosis and susceptibility assessment targeting of such oncogenes will be promising for improvement in treatment and prevention of cancer, thereby contributing to human healthcare. Here we review recent knowledge on molecular diagnosis of sporadic cancers, with focus on K-ras and beta-catenin oncogenes.