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Expression patterns of carcinogen detoxifying genes (CYP1A1, GSTP1 & GSTT1) in HNC patients

Nosheen Masood1, Mahmood Akhtar Kayani

  • 1Cancer Genetics Lab, Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan. nosheenmasood@hotmail.com

Pathology Oncology Research : POR
|August 25, 2012
PubMed

Insights

Head and neck cancer (HNC) patients show decreased activity of carcinogen-detoxifying enzymes like GSTs. Altered expression of CYP1A1, GSTT1, and GSTP1 in HNC tissues suggests a role in cancer development.

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • Carcinogen-detoxifying genes, including phase I (CYP1A1) and phase II (GSTs) enzymes, are crucial for metabolizing and excreting harmful compounds.
  • Abnormal expression of these genes is implicated in the initiation and progression of various cancers, including head and neck cancer (HNC).

Purpose of the Study:

  • To investigate the protein expression and activity of carcinogen-detoxifying enzymes (CYP1A1, GSTT1, GSTP1) in head and neck cancer (HNC) patients.
  • To determine the association between the expression of these detoxifying molecules and HNC development in the Pakistani population.

Main Methods:

  • Serum samples from 192 HNC patients and healthy controls were analyzed for GSTs specific activity using ELISA.
  • Immunohistochemistry was employed to assess the protein expression of CYP1A1, GSTT1, and GSTP1 in 49 HNC tissues and adjacent non-cancerous tissues.

Main Results:

  • Mean serum GSTs specific activity was significantly lower in HNC patients (7.7 U/L) compared to controls (11.4 U/L) (P < 0.001).
  • Immunohistochemistry revealed down-regulation of CYP1A1 and GSTT1, and over-expression of GSTP1 in HNC tissues compared to adjacent normal tissues.
  • Specific staining patterns indicated reduced CYP1A1 and GSTT1, and predominantly strong GSTP1 expression in HNC tissues.

Conclusions:

  • Altered expression and activity of carcinogen-detoxifying enzymes, including CYP1A1, GSTT1, and GSTP1, are associated with head and neck cancer.
  • These molecular changes may indicate a compromised DNA repair mechanism, contributing to HNC pathogenesis.
  • The findings highlight the potential role of these detoxifying molecules in HNC development within the studied population.

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