The cytoplasmic deacetylase HDAC6 is required for efficient oncogenic tumorigenesis

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Histone deacetylase inhibitors (HDACI) show promise as antitumor agents, but their precise mechanisms and targets remain unclear.
• The role of specific histone deacetylase (HDAC) members in supporting tumor growth is largely unknown.

Purpose of the Study:

• To investigate the role of HDAC6 in oncogenic transformation and tumor formation.
• To determine if HDAC6 is a potential target for cancer therapy.

Main Methods:

• Examined HDAC6 expression in oncogenically transformed fibroblasts.
• Assessed the impact of HDAC6 deficiency on oncogene-induced transformation (Ras, ErbB2).
• Inactivated HDAC6 in cancer cell lines and evaluated anchorage-independent growth and tumor formation in mice.
• Analyzed anoikis and signaling pathways (AKT, ERK) in HDAC6-deficient cells.
• Studied tumor development in HDAC6-null mice exposed to chemical carcinogens.

Main Results:

• HDAC6 expression increases upon oncogenic Ras transformation.
• Fibroblasts lacking HDAC6 exhibit resistance to Ras and ErbB2-driven transformation.
• HDAC6 inactivation reduces cancer cell anchorage-independent growth and tumorigenicity in vivo.
• Loss of HDAC6 leads to increased anoikis and impaired AKT/ERK activation upon cell detachment.
• HDAC6-null mice show reduced susceptibility to chemically induced skin tumors.

Conclusions:

• HDAC6 is a critical factor for oncogene-induced transformation and tumor growth.
• HDAC6 represents a specific HDAC member required for efficient oncogenesis.
• HDAC6 is a significant contributor to the antitumor effects of HDACIs and a potential therapeutic target.