OBJECTIVETo investigate the role of mutation and mRNA expression of tumor suppressor gene phosphatase and tensin homolog deleted in chromosome 10 (PTEN) in tumorigenesis and progression of oral squamous cell carcinoma (OSCC).

METHODSThe mutation of exon 3, 5, 6 and exon 8 of PTEN gene in 42 oral squamous cell carcinoma tissue and paired normal tissue were detected by polymerase chain reaction (PCR) and DNA sequencing methods. The levels of PTEN mRNA expression in these tissues were assayed using semi-quantitative RT-PCR. Data was analyzed with SPSS 14.0 software package.

RESULTSMutated exon 5 of PTEN gene was found in 2 cases of advanced OSCC. The expression of PTEN mRNA was detected in all OSCC and paired normal tissue. The level of PTEN mRNA in OSCC tissue (0.36 +/- 0.12) was significantly lower than that of paired normal tissue (0.64 +/- 0.09, P < 0.01).

CONCLUSIONSThe decreased expression of PTEN mRNA contributes to tumorigenesis of OSCC.

Carcinoma, Squamous Cell ; genetics ; Chromosomes, Human, Pair 10 ; Exons ; Gene Expression ; Genes, Tumor Suppressor ; Humans ; Microfilament Proteins ; Mouth Neoplasms ; genetics ; Mutation ; PTEN Phosphohydrolase ; genetics ; Phosphoric Monoester Hydrolases ; genetics ; Polymerase Chain Reaction ; RNA, Messenger ; metabolism ; Tensins

BACKGROUNDChronic hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC). Some HBV mutants and dysregulation of phosphatase and tensin homolog (PTEN) may promote the development of HCC synergistically. We aimed to test the effects of PTEN genetic polymorphisms and their interactions with important HBV mutations on the development of HCC in HBV-infected subjects.

METHODSQuantitative polymerase chain reaction was applied to genotype PTEN polymorphisms (rs1234220, rs2299939, rs1234213) in 1012 healthy controls, 302 natural clearance subjects, and 2011 chronic HBV-infected subjects including 1021 HCC patients. HBV mutations were determined by sequencing. The associations of PTEN polymorphisms and their interactions with HBV mutations with HCC risk were assessed using multivariate logistic regression analysis.

RESULTSRs1234220 C allele was significantly associated with HCC risk compared to healthy controls (adjusted odds ratio [AOR] = 1.35, 95% confidence interval [CI] = 1.07-1.69) and HCC-free HBV-infected subjects (AOR = 1.27, 95% CI = 1.01-1.57). rs1234220 C allele was significantly associated with increased frequencies of HCC-risk A1652G, C1673T, and C1730G mutations in genotype B HBV-infected subjects. Rs2299939 GT genotype was inversely associated with HCC risk in HBV-infected patients (AOR = 0.75, 95% CI = 0.62-0.92). The interaction of rs2299939 variant genotypes (GT+TT) with A3054T mutation significantly increased HCC risk (AOR = 2.41, 95% CI = 1.08-5.35); whereas its interaction with C3116T mutation significantly reduced HCC risk (AOR = 0.34, 95% CI = 0.18-0.66). These significant effects were only evident in males after stratification.

CONCLUSIONSPTEN polymorphisms and their interactions with HBV mutations may contribute to hepatocarcinogenesis in males. The host-virus interactions are important in identifying HBV-infected subjects who are more likely to develop HCC.

Carcinoma, Hepatocellular ; enzymology ; genetics ; DNA Mutational Analysis ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Liver Neoplasms ; enzymology ; genetics ; Microfilament Proteins ; genetics ; Mutation ; PTEN Phosphohydrolase ; genetics ; Phosphoric Monoester Hydrolases ; genetics ; Polymorphism, Genetic ; genetics ; Tensins

BACKGROUNDGastric cancer (GC) is one of the most prevalent malignancies in the world today, with a high mortality rate. CDX2 is a Drosophila caudal-related homeobox transcription factor that plays an important role in GC. Phosphatase and tensin homologue deleted from chromosome 10 (PTEN) is an important tumor suppressor which is widely expressed in normal human tissues. The aim of the study was to determine the relationship and mechanism between CDX2 and PTEN in invasion and migration of GC cells.

METHODSpcDNA3-CDX2 plasmids were transfected into MGC-803 cells to up-regulate CDX2 protein, and small interfering RNA-CDX2 was transfected to down-regulate CDX2. The influence of CDX2 or PTEN on cell migration and invasion was measured by invasion, migration and wound healing assays. Western blotting assay and immunofluorescence were used to detect the expression of CDX2, PTEN, phosphorylation of Akt, E-cadherin and N-cadherin. Statistical significance was determined by one-way analysis of variance.

RESULTSThe results showed that CDX2 reduced the migration and invasion of GC cells (P < 0.05), and inhibited the activity of Akt through down-regulating PTEN expression (P < 0.05). CDX2 also restrained epithelial-mesenchymal transition of GC cells.

CONCLUSIONSCDX2 inhibited invasion and migration of GC cells by PTEN/Akt signaling pathway, and that may be used for potential therapeutic target.

CDX2 Transcription Factor ; Cell Line, Tumor ; Cell Movement ; genetics ; physiology ; Chromosomes, Human, Pair 10 ; genetics ; Epithelial-Mesenchymal Transition ; genetics ; physiology ; Homeodomain Proteins ; genetics ; metabolism ; Humans ; Microfilament Proteins ; genetics ; metabolism ; PTEN Phosphohydrolase ; genetics ; Phosphoric Monoester Hydrolases ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Signal Transduction ; genetics ; physiology ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Tensins ; Wound Healing ; genetics ; physiology