Curcumin appears to be a safe, bioactive food compound that is a potential chemopreventive for patients at a high risk for head and neck squamous cell carcinoma (HNSCC). Identification and validation of intermediate endpoints is an important step in evaluating chemopreventive agents. AKT/ MTOR pathway biomarkers are intrinsic to the carcinogenic process as well as the mechanism of intervention with curcumin. Antiproliferative effects of curcumin were assayed in 9 HNSCC and a keratinocyte cell line. Nicotine, a genotoxic alkaloid involved in tobacco addiction, forms DNA adducts and has been implicated in upper aerodigestive tract cancer promotion. The antiproliferative effects of curcumin were associated with inhibition of the AKT/MTOR pathway in presence and absence of nicotine, which also induced this pathway. Curcumin was highly effective at suppressing growth of SCC40 xenografts and its activity is associated with modulation of MTOR's downstream target pS6. Curcumin at 15 mg significantly increased survival (286 AE 37 vs. 350 days) in the 4NQO carcinogenic model survival study. A major cause of lethal progression of HNSCC is local regional migration and invasion of malignant cells, and curcumin significantly inhibited cancer cell migration and invasion in vitro and in vivo where downregulation of pS6 was associated with a significant decrease in MMP-9. This is the first study to demonstrate that curcumin inhibits the adverse effects of nicotine by blocking nicotine-induced activation of the AKT/MTOR pathway in HNSCC, which retards cell migration. These studies indicate that inhibiting the AKT/MTOR pathway with curcumin may be useful as an oral chemopreventive agent. Cancer Prev Res; 3(12); 1586-95. Ó2010 AACR.

Problem The only definitive end point for studies of chemoprevention is the determination of the incidence of primary or secondary cancers which would require a multi-year study with thousands of subjects and tremendous costs. The identification and validation of intermediate endpoints would be an important step in evaluating chemopreventive agents. We have previously noted that curcumin, an exciting nutraceutical with promising chemopreventive effects in HNSCC, inhibited the Akt pathway. Hence we wanted to determine if there was a difference in expression of pAkt in tumors and adjacent mucosa of HNSCC patients when compared to non cancer patients. Methods 16 HNSCC and 16 non-cancer (sleep apnea) patient samples were analyzed by western blot for expression of phosphorylated Akt (pAkt(Ser473)). The SCC samples include tumors and adjacent mucosa. Results Phosphorylated Akt was elevated 12-fold in tumor samples compared to non-cancer patients. No expression of pAkt was seen in mucosa of 12/16 non-cancer patients while tumors and adjacent mucosa express pAkt in 15/16 HNSCC patients (p<0.05). Conclusion The pAkt/mTOR pathway may be sensitive as Akt/mTOR is activated in 99% of HNSCC and not uvulas suggesting pAkt is a good biomarker for a chemopreventive agent. Significance This preferential activation of the Akt pathway in HNSCC compared with the non-cancer patients could be useful in the design of clinical trials with curcumin. Support This work was supported by the Feist-Weiller Cancer Center and the American Society of Hematology.

Breast cancer is the second highest cause of cancer related deaths for women in developed countries. Breast cancer patients with distant metastasis at the time of diagnosis have an estimated 5-year relative survival rate of 26% as compared to a 99% survival rate of patients who have localized tumors. Evidence suggests that collagens play a role in enhancing the metastatic capability of breast cancer cells. Short chain collagen, collagen X, is encoded by the collagen type x alpha 1 chain (COL10A1) gene and is normally expressed exclusively by hypertrophic chondrocytes during endochondral ossification. Recently, COL10A1 gene expression has been found to be overexpressed in various tumor types, including breast tumors. It is hypothesized that an increase in COL10A1 expression may play a role in breast cancer metastasis. The goal of our project was to evaluate the role of collagen X in breast cancer metastasis using the MDA-MB-231 breast cancer cell line. Stable cell lines were generated to express either GFP only (MDA-VEC) or GFP tagged COL10A1 (MDA-COL). GFP and COL10A1 transcript and protein levels were examined to confirm overexpression of collagen X and transwell assays were used to determine changes in the invasive capability of the cells. Cells overexpressing collagen X demonstrated a higher rate of invasion suggesting that collagen X may play a role in enhancing the metastatic potential of breast cancer cells. Understanding the role collagen X plays in breast cancer metastasis may provide a mechanism for developing diagnostic and prognostic strategies for identifying patients whose breast cancer is more prone to metastasize. Citation Format: McKiernan K, Jimenez H, McEachern M, Hubbard J, O'Connell M. Role of collagen X in enhancing the metastatic potential of breast cancer cells using a MDA-MB-231 cell line model [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-16.