Preclinical Evidence

Curcumin inhibits skin squamous cell carcinoma tumor growth in vivo
Otolaryngol Head Neck Surg.  2011;145(1): 58-63
Cutaneous squamous cell carcinoma (SCCa) is one of the most common human malignancies, constitutes approximately 20-25% of non-melanoma skin cancers (NMSC). Over the past several decades, incidence of NMSC has gone up from 4% to 10%. Amongst all skin cancers, SCCa carries the highest rate of mortality, especially adults over age 85 years. Approximately 70% of cases of SCCa of the skin are found in the head and neck.

Several naturally occurring chemopreventive agents have studied in the recent past to deal with increasing incidence and morbidity of cutaneous SCCa. Curcumin is the one compound that has been studied more recently in this regard. It has been well established that Curcumin acts as a chemopreventive agent in a variety of cancers, and thus its role in the treatment of skin cancer and other skin diseases has also been explored.
Objective:

To determine whether curcumin has growth-inhibitory effects on cutaneous SCCa using an in vivo murine model.

Study Design:
  • Severe combined immunodeficiency (SCID) mice were pretreated with either corn oil (control) or 5 mg or 15 mg Curcumin once daily for 3 days prior to SCCa xenograft injection (n=8 per group)
  • Treatment was continued through day 24 along with daily measurement of tumors and body weight
  • At the end of the study, tumors were harvested
  • Tumors harvested on day 24 were used for immunohistochemical analysis of molecular markers in skin squamous cell carcinoma
  • Additionally, soluble proteins extracted from cell lines and tumor cells were analyzed by Western blot
Results and Discussion:
  • Group treated with 15 mg Curcumin showed a significant decrease in tumor growth rate compared to control group
  • Furthermore, 15 mg Curcumin treatment resulted in significant reduction in overall average tumor compared with the control group (p=0.0012)
  • Curcumin at highest dose showed a significant decrease in phosphorylated S6 expression, a well-accepted marker of mTOR activity in clinical trials, in tumors compared with control mice (p=0.0027)
Conclusion

Curcumin inhibited skin SCCa growth and blocked tumor progression by inhibiting pS6, indicating that it may help prevent skin cancer formation and progression.