RFC4 promotes the progression and growth of Oral Tongue squamous cell carcinoma in vivo and vitro

Objective Currently, many studies have found that RFC4 was up‐regulated in various cancers, and related to the progression and development. While the effects of RFC4 in oral tongue squamous cell carcinoma remain unclear, the main purpose of this research is to explore the role of RFC4 in oral tongue squamous cell carcinoma. Methods The expression of RFC4 in various cancers was analyzed in GEPIA database, and the results were further verified by IHC assay. The relationship between RFC4 and several clinical parameters was analyzed; the proliferation was further observed by knockdown RFC4 in vitro. Finally, we constructed related nude mouse models by planting cells subcutaneous of nude mice, and the discrepancy was observed. Results Based on GEPIA database, RFC4 was up‐regulated in various cancers, including colorectal cancer, breast cancer, prostate cancer, lung cancer, and liver cancer. RFC4 was up‐regulated in oral tongue squamous cell carcinoma compared with the normal tissue from GEPIA online database; we further found that the expression of RFC4 was tightly associated with TNM stage (p = 0.005), but not with age, gender, and differentiation (p > 0.05). We further found that the proliferation of oral tongue squamous cell carcinoma was obviously restrained in vitro, and the carcinogenesis was also inhibited in vivo. Conclusions We found that RFC4 was up‐regulated and related to the progression of oral tongue squamous cell carcinoma, and knockdown RFC4 could restrain the proliferation and progression. RFC4 might serve a potential biomarker and provide a new treatment strategy for lots of patients with oral tongue squamous cell carcinoma.
Figure 1. RFC4 was up‐regulated in various cancers. The expression of RFC4 in several cancers, including colorectal cancer, breast cancer, prostate cancer, lung cancer and liver cancer.Figure 2. The expression of RFC4 in oral tongue squamous cell carcinoma. Left panel: The expression of RFC4 in oral tongue squamous cell carcinoma (IHC), tissues were classified as low expression and high expression. Right panel: The expression of RFC4in normal tissues was used as normal control group. The expression of rfc4 in normal tissue is low and stain is weakly or negative.Table 1. Relationships of RFC4 and clinicopathological characteristics in 64 patients with tongue squamous cell carcinomaFigure 3. Knockdown RFC4 could restrain the proliferation of oral tongue squamous cell carcinoma CAL27 and TCA8113 cells. A. The mRNA expression of RFC4 in CAL27 and TCA8113 cells transfected with RFC4 shRNA. B. The protein expression of RFC4 in CAL27 and TCA8113 cells transfected with RFC4 shRNA. C. The CCK‐8 assay of CAL27 and TCA8113 cells transfected with RFC4 shRNA. D. The colony forming assay of CAL27 and TCA8113 cells transfected with RFC4 shRNA.Figure 4. Knockdown RFC4 inhibited the growth of oral tongue squamous cell carcinoma in vivo. A, B. CAL27 cell transfected with RFC4 shRNA was transplanted subcutaneously in nude mice, the tumor volume was measured with a caliper. C. IHC staining with RFC4 was performed in these tumors from nude mice.