Tumor Growth and Cell Proliferation Rate in Human Oral Cancer

Oral squamous cell cancer (SCC) has a high rate of morbidity and an overall 5-year survival rate for patients of 50%, statistics that have not changed in the last half century. A better understanding of the biological nature of this aggressive disease is mandatory. The two most studied human oral cancer cell lines-SCC-15 and SCC-25-share some biological characteristics but differ in others and may serve as a platform for further oral SCC analysis. We compared their basic carcinogenic characteristics, cellular proliferation rate and tumor growth, and discussed results according to available data from the literature and our own previous studies.

We examined doubling time both in vitro and in vivo of the SCC-15 and SCC-25 cell lines. After seeding the exact same number of cells in a six-well dish we counted them daily. To confirm doubling time differences in cells, we progressed to an in vivo model in nude mice using male 9- to 10-week-old BALB/c-nu/nu mice.

In both models (in vitro and in vivo) SCC-15 multiplied faster than SCC-25 cell line. In vivo the difference was more than double and in vitro this change was 24%.

Both SCC-15 and SCC-25 cell lines are suitable for further exploration of the oral carcinogenesis process. Based on our currently presented results and on the available literature, it seems that SCC-15 has an increased potential for local tumor growth and cell proliferation, whereas SCC-25 has a higher potential for invasion and metastasis.