Expression profile of CYP1A1 and CYP1B1 enzymes in endometrial tumors.

The cytochrome P450 CYP1A1 and CYP1B1 enzymes are phase I extrahepatic enzymes involved in the activation of pro-carcinogenic compounds to carcinogenic metabolites. Although differential overexpression of CYP1A1 and CYP1B1 has been documented at the messenger RNA (mRNA) and protein level, studies that have examined CYP1 expression by enzyme activity assays are limited. In the current study, the expression of CYP1A1 and CYP1B1 was investigated in a panel of human tumors of endometrial origin by quantitative reverse transcriptase PCR (qRT-PCR), Western blotting, and enzyme activity assays. The data revealed that approximately 36 % (5/14) and 43 % (6/14) of the endometrial tumors overexpressed CYP1A1 and CYP1B1 mRNA, whereas in 57 % of the endometrial tumors, CYP1 mRNA levels were downregulated. The mean mRNA levels of CYP1B1 and CYP1A1 in endometrial tumors did not show a significant difference compared to normal tissues (p > 0.05). Western blotting confirmed the qRT-PCR results and CYP1A1 and CYP1B1 proteins were shown to be downregulated in 7/14 (50 %) of the tumors and overexpressed in 4/14 (29 %) of the tumors. As regards to enzyme activity, 21 % (3/14) of the endometrial samples revealed elevated CYP1 activity levels across the tumor counterparts. Overall, the data suggest a putative downregulation of CYP1A1 and CYP1B1 expression in endometrial tumors, whereas overexpression of active CYP1 enzymes in 21 % of the tumors highlights the potential use of the latter enzymes as chemotherapeutic targets in endometrial cancer.

A case report of Hodgkin lymphoma in a patient treated with ustekinumab for psoriasis.

RATIONALE: Ustekinumab is a biological agent that inhibits interleukin 12 and 23 and has been approved for the treatment of moderate and severe plaque psoriasis. There have been case reports that raise concerns about its oncogenic potential. We are the first authors to report a case of Hodgkin lymphoma in a psoriatic patient receiving ustekinumab. PATIENT CONCERNS: A 22-year-old asymptomatic female patient presented to our department to investigate an enlarged cervical lymph node. Her past history was unremarkable, except for psoriasis since age 13. Two months before presentation the decision to administer Ustekinumab was taken and the patient had already received 3 doses. DIAGNOSES: During workup a Stage IV Hodgkin lymphoma was discovered. INTERVENTIONS: Ustekinumab administration was discontinued. The patient received treatment with the ABVD regimen. OUTCOMES: The patient's disease was refractory to the above-mentioned treatment. Therefore, a more aggressive regimen (BEACOPP escalated) was administered. LESSONS: Growing postmarketing surveillance data and case reports indicate that further research is warranted in order to elucidate a potential association between Ustekinumab and malignancy.

Expression profile of CYP1A1 and CYP1B1 enzymes in colon and bladder tumors.

BACKGROUND: The cytochrome P450 CYP1A1 and CYP1B1 enzymes are involved in carcinogenesis via activation of pro-carcinogenic compounds to carcinogenic metabolites. CYP1A1 and CYP1B1 have shown elevated levels in human tumors as determined by qRT-PCR and immunohistochemical studies. However studies that have examined CYP1 expression by enzyme activity assays are limited. RESULTS: In the current study the expression of CYP1A1 and CYP1B1 was investigated in a panel of human tumors of bladder and colorectal origin by qRT-PCR and enzyme activity assays. The results demonstrated that 35% (7/20) of bladder tumors and 35% (7/20) of colon tumors overexpressed active CYP1 enzymes. CYP1B1 mRNA was overexpressed in 65% and 60% of bladder and colon tumors respectively, whereas CYP1A1 was overexpressed in 65% and 80% of bladder and colon tumors. Mean mRNA levels of CYP1B1 and CYP1A1 along with mean CYP1 activity were higher in bladder and colon tumors compared to normal tissues (p<0.05). Statistical analysis revealed CYP1 expression levels to be independent of TNM status. Moreover, incubation of tumor microsomal protein in 4 bladder and 3 colon samples with a CYP1B1 specific antibody revealed a large reduction (72.5 ± 5.5 % for bladder and 71.8 ± 7.2% for colon) in catalytic activity, indicating that the activity was mainly attributed to CYP1B1 expression. CONCLUSIONS: The study reveals active CYP1 overexpression in human tumors and uncovers the potential use of CYP1 enzymes and mainly CYP1B1 as targets for cancer therapy.