COX-2 expression positively correlates with PD-L1 expression in human melanoma cells.

Abstract BACKGROUND: The resistance to PD-1/PD-L1 inhibitors for the treatment of melanoma have prompted investigators to implement novel clinical trials which combine immunotherapy with different treatment modalities. Moreover is also important to investigate the mechanisms which regulate the dynamic expression of PD-L1 on tumor cells and PD-1 on T cells in order to identify predictive biomarkers of response. COX-2 is currently investigated as a major player of tumor progression in several type of malignancies including melanoma. In the present study we investigated the potential relationship between COX-2 and PD-L1 expression in melanoma. METHODS: Tumor samples obtained from primary melanoma lesions and not matched lymph node metastases were analyzed for both PD-L1 and COX-2 expression by IHC analysis. Status of BRAF and NRAS mutations was analyzed by sequencing and PCR. Co-localization of PD-L1 and COX-2 expression was analyzed by double fluorescence staining. Lastly the BRAFV600E A375 and NRASQ61R SK-MEL-2 melanoma cell lines were used to evaluate the effect of COX-2 inhibition by celecoxib on expression of PD-L1 in vitro. RESULTS: BRAFV600E/V600K and NRASQ61R/Q61L were detected in 57.8 and 8.9% of the metastatic lesions, and in 65.9 and 6.8% of the primary tumors, respectively. PD-L1 and COX-2 expression were heterogeneously expressed in both primary melanoma lesions and not matched lymph node metastases. A significantly lower number of PD-L1 negative lesions was found in primary tumors as compared to not matched metastatic lesions (P = 0.002). COX-2 expression significantly correlated with PD-L1 expression in both primary (P = 0.001) and not matched metastatic (P = 0.048) lesions. Furthermore, in melanoma tumors, cancer cells expressing a higher levels of COX-2 also co-expressed a higher level of PD-L1. Lastly, inhibition of COX-2 activity by celecoxib down-regulated the expression of PD-L1 in both BRAFV600E A375 and NRASQ61R SK-MEL-2 melanoma cell lines. CONCLUSIONS: COX-2 expression correlates with and modulates PD-L1 expression in melanoma cells. These findings have clinical relevance since they provide a rationale to implement novel clinical trials to test COX-2 inhibition as a potential treatment to prevent melanoma progression and immune evasion as well as to enhance the anti-tumor activity of PD-1/PD-L1 based immunotherapy for the treatment of melanoma patients with or without BRAF/NRAS mutations

Metastatic eccrine porocarcinoma: report of a case and review of the literature

Eccrine porocarcinoma (EPC) is a rare type of skin cancer arising from the intraepidermal portion of eccrine sweat glands or acrosyringium, representing 0.005-0.01% of all cutaneous tumors. About 20% of EPC will recur and about 20% will metastasize to regional lymph nodes. There is a mortality rate of 67% in patients with lymph node metastases. Although rare, the occurrence of distant metastases has been reported

Metastatic eccrine porocarcinoma: report of a case and review of the literature

Abstract Eccrine porocarcinoma (EPC) is a rare type of skin cancer arising from the intraepidermal portion of eccrine sweat glands or acrosyringium, representing 0.005-0.01% of all cutaneous tumors. About 20% of EPC will recur and about 20% will metastasize to regional lymph nodes. There is a mortality rate of 67% in patients with lymph node metastases. Although rare, the occurrence of distant metastases has been reported. We report a case of patient with EPC of the left arm, with axillary nodal involvement and subsequent local relapse, treated by complete lymph node dissection and electrochemotherapy (ECT). EPC is an unusual tumor to diagnose. Neither chemotherapy nor radiation therapy has been proven to be of clinical benefit in treating metastatic disease. Although in the current case the short follow-up period is a limitation, we consider in the management of EPC a therapeutic approach involving surgery and ECT, because of its aggressive potential for loregional metastatic spread.</p

Effect of electrochemotherapy on human herpesvirus 8 kinetics in classic Kaposi sarcoma

Abstract Background Electrochemotherapy (ECT) has shown to be an effective treatment for cutaneous and subcutaneous Kaposi sarcoma (KS) lesions. However, no study has investigated the impact of ECT treatment on the kinetics of human herpesvirus type 8 (HHV8), which is considered the necessary causal agent of KS. We aimed to evaluate HHV8 viral load and expression levels in patients affected by classic KS who received one or more ECT treatments and have been followed semi annually for up to four years. Methods A total of 27 classic KS patients were enrolled in this study. Tumour biopsies and blood samples were obtained before ECT treatment. Additional blood samples were collected at six month intervals for 12–48 months. HHV8 viral load and expression profiles of latent (ORF72 and ORF73) and lytic (K2, K8, K8.1, K10/K10.1, K10.5/K10.6 and ORF16) genes were assessed in all samples by real-time PCR. HHV8 ORF26 and K1 regions were amplified and subjected to direct nucleotide sequencing followed by phylogenetic analysis for variant identification. Results All KS biopsies and 46.4% of peripheral blood mononuclear cells (PBMCs) collected before ECT treatment were positive for HHV8 DNA. Viral load ranged from 0.02 to 2.3 copies per cell in KS lesions and 3.0 × 10−7 to 6.9 × 10−4 copies per cell in PBMCs. Overall, latent ORF72 and ORF73 as well as lytic K2, K8 and K10/K10.1 were expressed in all KS biopsies. ORF16 mRNA was detected in 71.4% and both K8.1 and K10.5/K10.6 mRNAs in 57.1% of KS samples. The ORF72, ORF73 and K2 transcripts were amplified in 37.5%, 25% and 25% of PBMCs collected before ECT, respectively. After the first ECT session, complete response was achieved in 20 out of 27 (74.1%) patients and HHV8 DNA was detected in four out of 27 (14.8%) PBMC samples at six month follow up. Phylogenetic analysis of ORF26 amplimers showed that most viral variants belonged to A/C (82.3%), and few to C2 (5.9%) or C3 (11.8%) subtype. The K1/VR1 variants fell into A (33.3%) and C (66.7%) HHV8 clade. No correlation was found between HHV8 subtypes and ECT complete response. Conclusions ECT therapy has a significant effect on HHV8 kinetics in patients with classic KS. The complete remission of patients was accompanied by clearance of circulating virus

Differential expression of cyclooxygenase-2 in metastatic melanoma affects progression free survival

The possible correlation between cyclooxygenase-2 (COX-2) expression and disease progression in melanoma is still a matter of debate. Analysis of COX-2 expression in 45 lymph node melanoma metastases demonstrates a significant correlation between the percent of expression and progression free survival (PFS). A positive COX-2 expression ≥10% (COX-2(high)), as opposite to a positive expression ≤9% (COX-2(low)), translated into a striking significant reduction of PFS of about 3 years. The reduction in PFS correlated neither with BRAF(V600E) nor with NRAS(Q61) expression in the analyzed samples. This concept was reinforced by the finding that tumour development in COX-2(−/−) mice was almost blunted. Similarly, inhibition of COX-2 protein expression in human melanoma cell lines, by using siRNAs technology as well as selective inhibition of COX-2 activity by celecoxib, reduced cellular proliferation and invasiveness. In conclusion we show that COX-2(high) is a negative prognostic factor in metastatic melanoma. Our study also clarifies that the uncertainty about the role of COX-2 in metastatic malignant melanoma, found in the current relevant literature, is probably due to the fact that a threshold in COX-2 expression has to be reached in order to impact on cancer malignancy. Our findings suggest that COX-2 expression may become an useful diagnostic tool in defining melanoma malignancy as well as argue for a possible therapeutic use of NSAID as add on therapy in selected cases