Assessing SPP1/Osteopontin (OPN) Splice Variants and Their Association to Nonmelanoma Skin Cancer by Absolute Quantification: Identification of OPN-5 Subvariants and Their Protein Coding Potential

Abstract

The study evaluated whether SPP1/osteopontin (OPN) splice variants are differentially expressed in nonmelanoma skin cancer compared to normal skin. The absolute number of mRNA molecules of OPN-a predominated in normal skin and nonmelanoma skin cancer compared to OPN-b, OPN-c, and OPN-5. However, mRNAs of OPN-a, OPN-b, and OPN-c were expressed in higher levels in cutaneous squamous cell carcinomas (cSCCs) and basal cell carcinomas relative to normal skin. Additionally, OPN-5 expression was higher than OPN-b and OPN-c, and OPN-c, in normal skin and nonmelanoma skin cancer, respectively. Furthermore, we identified four OPN-5 splice variants, which were cloned and analyzed for protein expression.

Keywords:

• Osteopontin
• alternatively spliced variants
• cutaneous squamous cell carcinoma
• basal cell carcinoma
• absolute quantification
• OPN-5 subvariants

Acknowledgments

The authors greatly appreciate Dr. Donald Hill’s and Ms. Rebecca Lipscomb’s assistance in reviewing and editing the manuscript.

Author contributions

PLC conceived the study and drafted the manuscript; CCH provided material support. PLC and CFC designed and analyzed the study; CFC and NBD performed the experiments. All authors reviewed and approved the final version of the manuscript.

Disclosure statement

The authors declare no conflict of interest.