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Biomedical subjects

T Ijaz

Publications and source records attributed to T Ijaz.

6 recordsLinked to original sources
PubMed2002

The cancer preventative agent resveratrol is converted to the anticancer agent piceatannol by the cytochrome P450 enzyme CYP1B1.

Resveratrol is a cancer preventative agent that is found in red wine. Piceatannol is a closely related stilbene that has antileukaemic activity and is also a tyrosine kinase inhibitor. Piceatannol differs from resveratrol by having an additional aromatic hydroxy group. The enzyme CYP1B1 is overexpressed in a wide variety of human tumours and catalyses aromatic hydroxylation reactions. We report here that the cancer preventative agent resveratrol undergoes metabolism by the cytochrome P450 enzyme CYP1B1 to give a metabolite which has been identified as the known antileukaemic agent piceatannol. The metabolite was identified by high performance liquid chromatography analysis using fluorescence detection and the identity of the metabolite was further confirmed by derivatisation followed by gas chromatography-mass spectrometry studies using authentic piceatannol for comparison. This observation provides a novel explanation for the cancer preventative properties of resveratrol. It demonstrates that a natural dietary cancer preventative agent can be converted to a compound with known anticancer activity by an enzyme that is found in human tumours. Importantly this result gives insight into the functional role of CYP1B1 and provides evidence for the concept that CYP1B1 in tumours may be functioning as a growth suppressor enzyme.

Antineoplastic Agents↗
PubMed2001

Anthraquinone-peptides as inhibitors of AP-1 transcription factor.

Peptide-1-[N-[2-succinamidylethyl]amino]anthraquinones containing five seven amino acid residues including the KCR motif important in AP-1 protein binding to DNA have been synthesised as potential transcription factor inhibitors. These anthraquinone-peptides showed DNA intercalative binding and inhibition of AP-1 protein binding to its DNA consensus sequence.

Amino Acid Motifs↗
PubMed1998

Radiation therapy of pelvic recurrence after radical hysterectomy for cervical carcinoma.

OBJECTIVES: To evaluate the efficacy of radiation therapy and potential prognostic factors in patients treated for pelvic recurrence of cervical carcinoma after radical hysterectomy. MATERIALS: The records of 50 patients treated between 1964 and 1994 for an isolated pelvic recurrence of cervical carcinoma a median of 10.5 months after initial radical hysterectomy were retrospectively reviewed. Patients were categorized according to the extent of disease on clinical examination as group 1, mucosal involvement only (5); group 2, paravaginal extension (11); group 3, central recurrence with pelvic wall extension (13); and group 4, recurrences limited to the pelvic sidewall (21). Seven patients with group 3 or 4 disease who had a poor performance status were treated with palliative intent using hypofractionated radiotherapy. The remaining 43 patients were treated with curative intent, 33 with radiotherapy only and 10 with a combination of cisplatin-based chemotherapy and radiotherapy. Survival rates were calculated from the date of initial recurrence. Median follow-up of surviving patients was 109 months. RESULTS: The overall 5-year survival rate was 33% for all 50 patients (median survival, 18 months), 39% for the 43 patients treated with curative intent, and 25% for patients with isolated sidewall recurrences treated with curative intent. The survival rate was 69% for patients with group 1 and 2 disease and 18% for those treated with curative intent for group 3 disease (P = 0.07). The survival rate was better for patients with recurrent squamous carcinomas (51%) than for those with adenocarcinomas (14%) (P = 0. 05). Three group 4 patients who survived more than 5 years were treated with external-beam radiation alone. Eight-one percent of patients who had a second recurrence had evidence of disease progression. Three patients experienced late treatment complications. CONCLUSIONS: Patients who experience an isolated recurrence of cervical cancer after initial radical hysterectomy have an excellent prognosis if disease does not involve the pelvic wall. Occasional long-term survivors of recurrent disease involving the pelvic wall justify an aggressive treatment approach.

Adenocarcinoma↗
PubMed1997

Frontal sinus carcinoma: a case report and review of the literature.

A rare case of frontal sinus carcinoma is reported. The patient developed early recurrence following surgery, and was managed by accelerated hyperfractionated radiation therapy and concurrent cisplatinum-based systemic chemotherapy. The patient has remained disease-free for 30 months following the end of treatment.

Adult↗