NF-Kappa-B Downregulation Strategies in Head and Neck Cancer Treatment

Quantitative proteomic analysis of oral brush biopsies identifies secretory leukocyte protease inhibitor as a promising, mechanism-based oral cancer biomarker

A decrease in the almost fifty percent mortality rate from oral cancer is needed urgently. Improvements in early diagnosis and more effective preventive treatments could affect such a decrease. Towards this end, we undertook for the first time an in-depth mass spectrometry-based quantitative shotgun proteomics study of non-invasively collected oral brush biopsies. Proteins isolated from brush biopsies from healthy normal tissue, oral premalignant lesion tissue (OPMLs), oral squamous cell carcinoma (OSCC) and matched control tissue were compared. In replicated proteomic datasets, the secretory leukocyte protease inhibitor (SLPI) protein stood out based on its decrease in abundance in both OPML and OSCC lesion tissues compared to healthy normal tissue. Western blotting in additional brushed biopsy samples confirmed a trend of gradual decreasing SLPI abundance between healthy normal and OPML tissue, with a larger decrease in OSCC lesion tissue. A similar SLPI decrease was observed in-vitro comparing model OPML and OSCC cell lines. In addition, exfoliated oral cells in patients’ whole saliva showed a loss of SLPI correlated with oral cancer progression. These results, combined with proteomics data indicating a decrease in SLPI in matched healthy control tissue from OSCC patients compared to tissue from healthy normal tissue, suggested a systemic decrease of SLPI in oral cells correlated with oral cancer development. Finally, in-vitro experiments showed that treatment with SLPI significantly decreased NF-kB activity in an OPML cell line. The findings indicate anti-inflammatory activity in OPML, supporting a mechanistic role of SLPI in OSCC progression and suggesting its potential for preventative treatment of at-risk oral lesions. Collectively, our results show for the first time the potential for SLPI as a mechanism-based, non-invasive biomarker of oral cancer progression with potential in preventive treatment.

G31P, an antagonist against CXC chemokine receptors 1 and 2, inhibits growth of human prostate cancer cells in nude mice

Prostate cancer is the most common malignancy in Western countries. Chemokine C-X-C motif receptor 1 (CXCR1) and CXCR2 play a key role in generation and regulation of CXC chemokine signaling. CXCR1 is a receptor for interleukin 8 (IL8), a pro-inflammatory chemokine, and CXCR1/2 are crucially involved in the prostate cancer development and progression. Thus, we generated a high-affinity human CXCR1/CXCR2 inhibitor, CXCL8 (3-72) K11R/G31P, named G31P, which is a synthetic derivative of the human cytokine, IL-8. In this study, we investigated the effects of G31P on regulation of prostate cancer cell growth in vitro and in nude mouse xenografts. Cell viability, adhesion, and wound healing assays were used to assess the effects of G31P on growth, adhesion, and migration of PC-3 human prostate cancer cells in vitro, respectively. Nude mouse xenografts and xenograft implantation assays were performed to determine the effect of G31P on PC-3 cells in vivo. Immunohistochemistry was used to detect gene expression, and fluorescence imaging was used to detect tumor volume and microvessel density in tumor xenografts. The data showed that G31P treatment significantly reduced PC-3 cell viability, adhesion and migration capacity in a dose-dependent manner (up to 100 ng/ml). Additionally, G31P treatment of nude mice suppressed the growth of orthotopically transplanted tumor xenografts. G31P also inhibited tumor tissue vascularization, which was associated with the decreased expression of vascular endothelial growth factor and nuclear transcription factor (NF)-κB in orthotopic xenograft tissues. This study provides evidence that G31P, a CXCR1/2 inhibitor, may effectively control prostate cancer.

Inositol Hexaphosphate and Paclitaxel: Symbiotic Treatment of Oral Cavity Squamous Cell Carcinoma

OBJECTIVES/HYPOTHESIS

Nuclear factor (NF)-kappaB is an early response gene that has been associated with head and neck squamous cell cancer (HNSCC) progression. NF-kappaB activation is induced by some chemotherapy agents, including paclitaxel. The activation of this gene can be correlated with apoptosis resistance. Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate. NF-kappaB levels were evaluated in oral cavity HNSCC lines after treatment with paclitaxel and IP6, alone and in combination. Resulting levels of cell death and apoptosis were assessed, and conclusions are drawn regarding a possible synergistic relationship between paclitaxel and IP6.

METHODS

NF-kappaB activation in cancer cells treated with paclitaxel and IP6, alone and in combination, was measured by transient transfection, and results were interpreted by luminometry. Cell proliferation of treated cells was measured by MTT assay. Cell viability and apoptosis of cancer cells treated with paclitaxel and IP6 combinations were quantitated by trypan blue staining and Caspase-Glo 3/7 assay, respectively.

RESULTS

IP6 was observed to significantly downregulate NF-kappaB activation in both NA and CA-9-22 oral cavity HNSCC cell lines. Paclitaxel treatments caused increased NF-kappaB activation in the same cell lines. IP6 was observed to mitigate paclitaxel-induced NF-kappaB activation in the CA-9-22 cell line. IP6, when combined with paclitaxel, reduces CA-9-22 cell proliferation, increases cell death, and increases apoptosis, when compared with treatment with paclitaxel alone.

CONCLUSIONS

IP6 reduces paclitaxel induced NF-kappaB activation and increases paclitaxel-mediated cell killing and apoptosis. As a well-tolerated and safe supplement, IP6 deserves further study in the treatment of oral cavity squamous cell carcinoma.

Coordinated upregulation of COX-2 and NF-kappaB is a steady feature of laryngeal carcinogenesis

BACKGROUND/AIMS

Laryngeal cancer is the endpoint of a multistage process involving hyperplastic and dysplastic lesions, not adequately defined in their molecular aspect. Our objective was to evaluate the expression of the prostaglandin-synthesizing enzyme cyclooxygenase-2 (COX-2) and the chief transcription factor nuclear factor-kappaB (NF-kappaB) in laryngeal carcinomas and their precursors, as well as to explore any association between the two molecules.

METHODS

We performed paraffin section immunohistochemistry for COX-2 and the p65 subunit of NF-kappaB, in tissues from 129 patients with tumors or premalignancies. p65 cytoplasmic and nuclear immunostaining were listed individually.

RESULTS

COX-2 was positively correlated with histopathological grading from normal mucosa to carcinomas (Spearman's coefficient r(s) = 0.286, p < 0.001). No association was revealed between COX-2 expression and tumor grade. p65 immunoreactivity, both of cytoplasmic and nuclear origin, increased along the carcinogenesis course, manifesting highest expression in invasive cancer (r(s) = 0.419, p < 0.001 and r(s) = 0.241, p < 0.001, respectively). Again, tumor grade had no influence on expression. COX-2 and p65 cytoplasmic, but no nuclear, expression showed a positive correlation (r(s) = 0.352, p < 0.001).

CONCLUSIONS

This study demonstrates that lesional advance in the larynx towards cancer is marked by ongoing upregulation of COX-2 and NF-kappaB. Synchronism between individual expressions may denote a regulatory role of the latter in COX-2 transactivation.