Biomedical subjects

A N Cheung

Publications and source records attributed to A N Cheung.

57 records · Page 4Linked to original sources

PubMedDate not supplied

Expressions of c-erbB-2, epidermal growth factor receptor and pan-ras proto-oncogenes in adenocarcinoma of the cervix: correlation with clinical prognosis.

The expressions of c-erbB-2, epidermal growth factor receptor (EGFR) and pan-ras in normal cervical glands (n=45), glandular dysplasia/adenocarcinoma in situ (GIN/ACIS) (n=32) and invasive cervical adenocarcinoma (n=78) were determined and correlated with clinical prognosis. The expressions of c-erbB-2, EGFR and pan-ras in GIN/ACIS lesions and invasive tumours were significantly higher than in normal glands (p<0.001), whereas there was no significant difference between expressions in GIN/ACIS lesions and invasive tumours, except for EGFR (p=0.016). Significantly more normal glands adjacent to adenocarcinoma showed moderate/strong expressions for EGFR than c-erbB-2 (p=0.007) whereas significantly more GIN/ACIS lesions showed moderate/strong expressions for c-erbB-2 than EGFR (p=0.008). No correlation was found between moderate/strong expressions for c-erbB-2, EGFR or pan-ras and stage at presentation (p=0.384, 0.056, 0.842 respectively) or with survival (p=0.58, 0.19, 0.26 respectively). In conclusion, EGFR is more important in inducing dysplastic change/malignant transformation whereas c-erbB-2 plays a more significant role in tumour progression and invasion. However, neither c-erbB-2, EGFR nor pan-ras carried any prognostic significance on patient survival.

Adenocarcinoma↗

PubMedDate not supplied

Abnormal expression of pan-ras, c-myc and tp53 in squamous cell carcinoma of cervix: correlation with HPV and prognosis.

The aim of this study is to assess, in squamous cell carcinoma of the cervix, the expression of pan-ras, c-myc and tp53 at protein level using an immunohistochemical (IHC) staining method. One hundred and seven patients with squamous cell carcinoma of the cervix were recruited. Fifty-four patients were of stage 1B/2A and 53 were of stage 2B and above. Positive IHC stainings of pan-ras, c-myc and tp53 proteins were detected in 80.4%, 32.7% and 25.2% of cases, respectively. No significant correlation between overexpression of pan-ras and c-myc was detected. However, significantly higher percentages of overexpression of c-myc was found in association with overly expressed tp53 samples (p = 0.014). Human papillomavirus (HPV) was detected in 77.6% of cancers. HPV 16/18 was detected in 72% of cancers. Overexpression of pan-ras and c-myc had no correlation with HPV detection and stage. However, higher percentages of overexpression of tp53 were found in early stage disease (p = 0.017) and in HPV 16/18 positive tumors (p = 0.006). Overexpression of pan-ras, c-myc and tp53 alone or in more than one oncogenes had no prognostic significance on survival.

Adult↗

PubMedDate not supplied

Expression of vascular endothelial growth factor in third-trimester placentas is not increased in growth-restricted fetuses.

OBJECTIVE: Vascular endothelial growth factor (VEGF) is considered the growth factor that stimulates vasculogenesis and angiogenesis. Recent studies have demonstrated its role in regulating placental growth and invasion. Its expression can be upregulated by hypoxia. Intrauterine growth restriction (IUGR) is thought to be associated with inadequate placental perfusion, which might result from a failure in the development of the villous vascular network. Our present study was undertaken to examine the relationship between VEGF expression and IUGR in pregnancies with preserved umbilical artery end-diastolic flow. METHODS: VEGF Expression was determined by immunohistochemical analysis of placentas from 17 pregnancies with normal infant birth weight and 17 pregnancies complicated by IUGR. RESULTS: We found no significant differences in the expression of VEGF in villous syncytiotrophoblasts and intermediate trophoblasts in maternal decidua between IUGR and normal pregnancies. However, in both groups there was a strong correlation in the expression of VEGF with villous syncytiotrophoblasts and intermediate trophoblasts. In normal and IUGR pregnancies the infants' Apgar scores at birth were significantly correlated with VEGF staining in both syncytiotrophoblasts and intermediate trophoblasts (P < .05). A strong correlation also was found between cord hematocrit and VEGF staining in villous syncytiotrophoblasts (P < .05), but VEGF staining in intermediate trophoblasts was not correlated with cord hemoglobin or hematocrit. CONCLUSIONS: Our results suggest that VEGF acts in an autocrine and paracrine fashion in both normal and IUGR placentas, and its expression can have an effect on the well being of the infant at birth.

Birth Weight↗