OBJECTIVE: This study aimed to detect the presence of microsatellite (MSI) and loss of heterozygosity (LOH) of the Deleted in Colorectal Cancer (DCC) gene in normal and tumor tissues of Filipino colorectal cancer patients and examine its correlation with age, gender, tumor grade, tumor stage and site of lesion.
METHODS: Paired frozen normal and tumor tissues from thirtynine (39) patients with colorectal adenocarcinoma were used by polymerase chain reaction (PCR). Single strand conformation polymorphism - polyacrylamide gel electrophoresis (SSCP - PAGE) was used to determine MSI and restriction fragment length polymorphism (RFLP) was used to study LOH.
RESULTS: Based on our data, out of the 39 patients, 10 showed LOH of the DCC gene using the LOH markers VNTR, M2 and M3, while no MSI was detected in the samples using the MSI markers BAT25 and BAT26. Correlation with clinicopathological characteristics showed that there is significance for the site of lesion. The LOH has correclation with tumor samples from the colon but not with those from the rectum.
CONCLUSION: Preliminary screening for MSI and LOH of the DCC gene shows that occurrences of colorectal cancer among Filipino patients can be correlated with LOH of the DCC gene with colorectal cancer in a Filipino sample population.

Human ; Male ; Female ; Aged 80 And Over ; Aged ; Middle Aged ; Adult ; Genes, Dcc ; Polymorphism, Single-stranded Conformational ; Colorectal Neoplasms ; Adenocarcinoma ; Loss Of Heterozygosity

INTRODUCTION: Chromosomal mutations are casual events in neoplasia development. Biomarker cytogenetic assays can determine exposure to mutagenic agents in occupational settings. This study assessed early biological marker chromosomal aberrations among health workers in the chemotheraphy oncology wards/ clinics, exploring its association to the subjects' occupational, environmental and baseline profile.
METHODS: This was an IRB approved cross-sectional exploratory study among hospital personnel working in the chemotherapy oncology facility of a tertiary government hospital, who underwent structured interview and blood extraction for cytogenetic assay after informed consent. Study funds only permitted assay of 44 specimens of 144 planned sample size, hence, Stata 6.0 only analyzed data from 44 subjects.
RESULTS: All 44 subjects had varying exposure to chemotherapy drug infusions. Of these, 79% had 1.0 breaks per cell (hypersensitive). Predominantly chromatid breaks (CTB), chromatid gaps (CTG), sister chromatid exhanges (SCE) were seen. No significant association was shown between mutagenic sensitivity and baseline characteristics, but with small sample size.
CONCLUSION: 21% borderline to hypersensitive mutagenic sensitivity among oncology workers at the tertiary government hospital is relatively significant, despite small sample size, connoting a must preventive promotive practice of chemotherapy administration in the workplace.

Human ; Male ; Female ; Chromosome Aberrations ; Chromosomes ; Drug Therapy ; Personnel, Hospital ; Cytogenetics ; Chromatids ; Mutagens

We report a case of a Filipino male diagnosed with Noonan syndrome on the basis of facial dysmorphism, chest deformity, short stature, mental and skeletal retardation, pulmonic stenosis and hypogonadism. In addition, he has three clinical features which are not known to be associated with the syndrome and are perhaps being reported for the first time:structurally normal kidneys with nephrotic syndrome, pituitary macroadenoma and pes varus.

Human ; Male ; Adolescent ; Noonan Syndrome ; Nephrotic Syndrome ; Dwarfism ; Pulmonary Valve Stenosis ; Hypogonadism ; Musculoskeletal System

Objective: To detect and characterize retinoblastoma susceptibility gene (RB1) mutations in tumor samples collected from Filipino patients with retinoblastoma. Methods: Six tumor samples were obtained from Filipino patients diagnosed with retinoblastoma. DNA was extracted from the tumor samples and exons 13-21 of the RB1 gene were amplified by polymerase chain reaction (PCR). PCR amplification products were subsequently purified and sequenced. Mutation detection and characterization were done by alignment of obtained sequences to the RB1 reference sequence from NCBI GenBank using Bioedit® software. The identified mutations were correlated with clinical presentation and family history. These mutations were also compared to known mutations reported in the RB1 Gene Mutation Leiden Open Variation Database (LOVD). Results: Mutations were detected in two out of the six samples. In a patient with unilateral disease and no family history, two mutations were identified: a novel CGT>AGT (Arginine → Serine) missense mutation in position c.1861 of exon 19 and a previously reported CGA>TGA (Arginine → STOP) nonsense mutation in position c. 1735 of exon 18. A possible large exonic deletion was identified in a case of unilateral disease with no family history. Conclusion We were able to identify both novel and known mutations in the RB1 gene of Filipino retinoblastoma cases using DNA sequencing techniques. These techniques may be applied to further characterize the genetic mutations of Filipino retinoblastoma cases and their families in developing a rational method of genetic testing for early diagnosis and counseling.
Retinoblastoma ; Genes, Retinoblastoma