Long noncoding RNA-HOTAIR affects chemoresistance by regulating HOXA1 methylation in small cell lung cancer cells

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Homeobox (HOX) transcript antisense RNA (HOTAIR), a long intergenic noncoding RNA (lincRNA), is implicated in various cancers.
• Its role in small cell lung cancer (SCLC) chemoresistance remains largely unexplored.

Purpose of the Study:

• To investigate the function of HOTAIR in SCLC chemoresistance.
• To elucidate the underlying molecular mechanisms of HOTAIR-mediated chemoresistance.

Main Methods:

• HOTAIR knockdown in multidrug-resistant and parental SCLC cell lines.
• Assessment of drug sensitivity, apoptosis, and cell cycle progression.
• Analysis of HOXA1 methylation using bisulfite sequencing PCR.
• Evaluation of DNA methyltransferase (DNMT) expression.
• RNA immunoprecipitation to validate HOTAIR-HOXA1 interaction.
• In vivo tumor growth suppression studies.

Main Results:

• Downregulation of HOTAIR sensitized SCLC cells to anticancer drugs, enhanced apoptosis, and induced cell cycle arrest.
• HOTAIR depletion suppressed tumor growth in vivo.
• Resistant SCLC cells exhibited increased HOXA1 methylation.
• HOTAIR knockdown reduced HOXA1 methylation by decreasing DNMT1 and DNMT3b expression.
• Direct interaction between HOTAIR and HOXA1 was confirmed.

Conclusions:

• HOTAIR plays a significant role in mediating chemoresistance in SCLC.
• The mechanism involves HOTAIR regulating HOXA1 methylation via DNMT1 and DNMT3b.
• HOTAIR represents a potential therapeutic target for overcoming chemoresistance in SCLC adjuvant therapies.