Cannibalism of Live Lymphocytes by Human Metastatic but Not Primary Melanoma Cells

The phenomenon of cell cannibalism, which generally refers to the engulfment of cells within other cells, was described in malignant tumors, but its biological significance is still largely unknown. In the present study, we investigated the occurrence, the in vivo relevance, and the underlying mechanisms of cannibalism in human melanoma. As first evidence, we observed that tumor cannibalism was clearly detectable in vivo in metastatic lesions of melanoma and often involved T cells, which could be found in a degraded state within tumor cells. Then, in vitro experiments confirmed that cannibalism of T cells was a property of metastatic melanoma cells but not of primary melanoma cells. In particular, morphologic analyses, including time-lapse cinematography and electron microscopy, revealed a sequence of events, in which metastatic melanoma cells were able to engulf and digest live autologous melanoma-specific CD8+ T cells. Importantly, this cannibalistic activity significantly increased metastatic melanoma cell survival, particularly under starvation condition, supporting the evidence that tumor cells may use the eating of live lymphocytes as a way to ‘‘feed’’ in condition of low nutrient supply. The mechanism underlying cannibalism involved a complex framework, including lysosomal protease cathepsin B activity, caveolae formation, and ezrin cytoskeleton integrity and function. In conclusion, our study shows that human metastatic melanoma cells may eat live T cells, which are instead programmed to kill them, suggesting a novel mechanism of tumor immune escape. Moreover, our data suggest that cannibalism may represent a sort of ‘‘feeding’’ activity aimed at sustaining survival and progression of malignant tumor cells in an unfavorable microenvironment. (Cancer Res 2006; 66(7): 3629-38

A large de novo 9p21.3 deletion in a girl affected by astrocytoma and multiple melanoma.

BACKGROUND: Association of melanoma, neural system tumors and germ line mutations at the 9p21 region in the CDKN2A, CDKN2B and CDKN2BAS genes has been reported in a small number of families worldwide and described as a discrete syndrome in melanoma families registered as a rare disease, the melanoma–astrocytoma syndrome. CASE PRESENTATION: We here studied two young patients developing melanoma after radiotherapy for astrocytoma, both reporting lack of family history for melanoma or neural system tumors at genetic counselling. Patient A is a girl treated for anaplastic astrocytoma at 10 years and for multiple melanomas on the scalp associated to dysplastic nevi two years later. Her monozygotic twin sister carried dysplastic nevi and a slow growing, untreated cerebral lesion. Direct sequencing analysis showed no alterations in melanoma susceptibility genes including CDKN2A, CDK4, MC1R and MITF or in TP53. By microsatellite analysis, multiplex ligation-dependent probe amplification, and array comparative genomic hybridization a deletion including the CDKN2A, CDKN2B and CDKN2BAS gene cluster was detected in both twin sisters, encompassing a large region at 9p21.3 and occurring de novo after the loss of one paternal allele. Patient B is a boy of 7 years when treated for astrocytoma then developing melanoma associated to congenital nevi on the head 10 years later: sequencing and multiplex ligation-dependent probe amplification revealed a normal profile of the CDKN2A/CDKN2B/CDKN2BAS region. Array comparative genomic hybridization confirmed the absence of deletions at 9p21.3 and failed to reveal known pathogenic copy number variations. CONCLUSIONS: By comparison with the other germ line deletions at the CDKN2A, CDKN2B and CDKN2BAS gene cluster reported in melanoma susceptible families, the deletion detected in the two sisters is peculiar for its de novo origin and for its extension, as it represents the largest constitutive deletion at 9p21.3 region identified so far. In addition, the two studied cases add to other evidence indicating association of melanoma with exposure to ionizing radiation and with second neoplasm after childhood cancer. Melanoma should be considered in the monitoring of pigmented lesions in young cancer patients

Phenotypic and functional analysis of lymphocytes infiltrating osteolytic tumors: use as a possible therapeutic approach of osteosarcoma

BACKGROUND: Osteosarcoma is the most common type of primary bone tumor. The use of aggressive chemotherapy has drastically improved the prognosis of the patients with non-metastatic osteosarcomas, however the prognosis of the patients with metastasis is still very poor. Then, new and more effective treatments for curing osteosarcoma, such as immunotherapy are needed. Tumor-infiltrating lymphocytes (TIL) have been involved in the control of tumor development and already assessed with success for the treatment of several cancers including melanoma. While TIL represent a fascinating therapeutic approach in numerous malignant pathologies, there is few report concerning adult bone-associated tumors including osteosarcoma. METHODS: Human TIL were isolated and characterized (phenotype, lytic activity) from twenty-seven patients with bone-associated tumors (osteosarcoma, Ewing's sarcoma, giant cell tumor, chondrosarcoma, plasmocytoma and bone metastases). Similar experiments were performed using rat osteosarcoma model. RESULTS: While TIL with a main CD4(+ )profile were easily isolated from most of the tumor samples, only TIL extracted from osteosarcoma were cytotoxic against allogeneic tumor cells. In all cases, TIL lytic activity was significantly higher compared to autologous peripheral blood leukocytes. Similar data were observed in rat osteosarcoma model where TIL were characterized by a main CD4(+ )profile and high lytic activity against allogeneic and autologous tumor cells. Moreover, rat TIL expansion was not accompanied by refractoriness to further activation stimulus mainly by tumor antigens. CONCLUSION: These results demonstrated that TIL therapy could be a very efficient strategy for the treatment of adult osteosarcoma

Efficacy of mRNA anti-SARS-CoV-2 vaccination and dynamics of humoral immune response in patients with solid tumors: results from the institutional registry of an italian tertiary cancer center

Background: Systemic immunosuppression characterizing cancer patients represents a concern regarding the efficacy of anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination, and real-world evidence is needed to define the efficacy and the dynamics of humoral immune response to mRNA-based anti-SARS-CoV-2 vaccines. Methods: We conducted an observational study that included patients with solid tumors who were candidates for mRNA anti-SARS-CoV-2 vaccination at the Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. The primary objective was to monitor the immunologic response to the mRNA anti-SARS-CoV-2 vaccination in terms of anti-spike antibody levels. All the patients received two doses of the mRNA-1273 vaccine or the BNT162b2 vaccine. Healthcare workers served as a control group of healthy subjects. Results: Among the 243 patients included in the present analysis, 208 (85.60%) and 238 (97.94%) resulted seroconverted after the first and the second dose of vaccine, respectively. Only five patients (2.06%) had a negative titer after the second dose. No significant differences in the rate of seroconversion after two vaccine doses were observed in patients as compared with the control group of healthy subjects. Age and anticancer treatment class had an independent impact on the antibody titer after the second dose of vaccination. In a subgroup of 171 patients with available data about the third timepoint, patients receiving immunotherapy with immune checkpoint inhibitors seem to have a higher peak of antibodies soon after the second dose (3 weeks after), but a more pronounced decrease at a late timepoint (3 months after). Conclusions: The systemic immunosuppression characterizing cancer patients did not seem to dramatically affect the humoral response to anti-SARS-CoV-2 mRNA vaccines in our population of patients with solid tumors. Further investigation is needed to dissect the interplay between immunotherapy and longitudinal dynamics of humoral response to mRNA vaccines, as well as to analyze the cellular response to mRNA vaccines in cancer patients

Granulocytes mediates the Fas-L-associated apoptosis during lung metastasis of melanoma that determines the metastatic behaviour

The survival of tumour cells in a new tissue environment is crucial for tumour metastasis. Factors contributing to the death of tumour cells during metastasis are not completely understood. In murine melanoma model, activation of Fas (CD95, APO-1) signal in tumour cells reduces their lung metastasis potential, which may be associated with an induction of apoptosis in tumours. To elucidate the cellular mechanism, we used a Fas-ligand (Fas-L) specific ribozyme (Fas-Lribozyme) to suppress the expression of Fas-L but not Fas or TNF-α in B16F10 melanoma cells. The Fas-Lribozyme-carrying cells grew slightly faster in vitro with better viability than controls. Suppression of Fas-L in B16F10 melanoma cells by Fas-Lribozyme enhanced lung metastasis of the cells in C57BL/6 mice, and that was correlated with reductions in both apoptotic tumour cells and granulocytic infiltration. Mice depleted of granulocytes, but not CD4+ and CD8+ cells, showed a greatly elevated susceptibility to lung metastasis. Moreover, apoptosis in tumour cells was significantly reduced in granulocyte-depleted mice during the course of tumour formation. Taken together, our findings indicate that Fas-L-associated apoptosis in tumour cells determines the metastasis behaviour of melanoma in the lung and this apoptosis is primarily mediated by the cytotoxicity of recruited granulocytes

Overcoming melanoma resistance to vemurafenib by targeting CCL2-induced miR-34a, miR-100 and miR-125b

In melanoma, the adaptative cell response to BRAF inhibitors includes altered patterns of cytokine production contributing to tumor progression and drug resistance. Among the factors produced by PLX4032-resistant melanoma cell lines, CCL2 was higher compared to the sensitive parental cell lines and increased upon drug treatment. CCL2 acted as an autocrine growth factor for melanoma cells, stimulating the proliferation and resistance to apoptosis. In patients, CCL2 is detected in melanoma cells in tumors and in plasma at levels that correlate with tumor burden and lactate dehydrogenase. Vemurafenib treatment increased the CCL2 levels in plasma, whereas the long-term clinical response was associated with low CCL2 levels. Increased CCL2 production was associated with miRNA deregulation in the resistant cells. miR-34a, miR-100 and miR-125b showed high expression in both resistant cells and in tumor biopsies that were obtained from treated patients, and they were involved in the control of cell proliferation and apoptosis. Inhibition of CCL2 and of the selected miRNAs restored both the cell apoptosis and the drug efficacy in resistant melanoma cells. Therefore, CCL2 and miRNAs are potential prognostic factors and attractive targets for counteracting treatment resistance in metastatic melanoma

Vaccination of metastatic renal cell carcinoma patients with autologous tumour-derived vitespen vaccine: clinical findings

The aim of this study was to evaluate the clinical efficacy as determined by time to progression and response rate (RR) of autologous vitespen (formerly HSPPC-96; Oncophage, Antigenics Inc., New York, NY, USA) with and without interleukin-2 (IL-2; Proleukin: Chiron, Emoryville, CA, USA) in stage IV metastatic renal cell carcinoma (RCC) patients undergoing nephrectomy. Eighty-four patients were enrolled on study, and then underwent nephrectomy and harvest of tumour tissue for use in autologous vaccine manufacture. Initial treatment schedule started approximately 4 weeks after surgery and consisted of six injections: once weekly for 4 weeks, then two injections biweekly (vaccines administered at weeks 1, 2, 3, 4, 6, 8), followed by restaging at or around week 10. Patients who had stable or responsive disease continued to receive vaccine, with four more vaccinations biweekly (at weeks 10, 12, 14, 16). Patients who had progressive disease at week-10 evaluation received four consecutive 5-day-per-week courses of 11 × 106 U of IL-2 subcutaneously (weeks 10, 11, 12, 13), with four doses of vitespen at 2-week intervals (at weeks 10, 12, 14, 16). At the next evaluation (week 18), patients with a complete response received two further cycles of vitespen (with IL-2 if also received during prior cycle) or until vaccine supply was exhausted. Patients with stable disease or partial response repeated their prior cycle of therapy. Disease progressors who had not yet received IL-2 began IL-2 treatment, and progressors who had already received IL-2 came off study. Of 60 evaluable patients, 2 demonstrated complete response (CR), 2 showed partial response (PR), 7 showed stable disease, and 33 patients progressed. Sixteen patients had unconfirmed stable disease. Two patients who progressed on vaccine alone experienced disease stabilisation when IL-2 was added. Treatment with vitespen did not result in a discernable benefit in the majority of patients with metastatic RCC treated in this study. Use in combination with immunoregulatory agents may enhance the efficacy of vitespen

Cystatin E/M suppresses legumain activity and invasion of human melanoma

<p>Abstract</p> <p>Background</p> <p>High activity of cysteine proteases such as legumain and the cathepsins have been shown to facilitate growth and invasion of a variety of tumor types. In breast cancer, several recent studies have indicated that loss of the cysteine protease inhibitor cystatin E/M leads to increased growth and metastasis. Although cystatin E/M is normally expressed in the skin, its role in cysteine protease regulation and progression of malignant melanoma has not been studied.</p> <p>Methods</p> <p>A panel of various non-melanoma and melanoma cell lines was used. Cystatin E/M and C were analyzed in cell media by immunoblotting and ELISA. Legumain, cathepsin B and L were analyzed in cell lysates by immunoblotting and their enzymatic activities were analyzed by peptide substrates. Two melanoma cell lines lacking detectable secretion of cystatin E/M were transfected with a cystatin E/M expression plasmid (pCST6), and migration and invasiveness were studied by a Matrigel invasion assay.</p> <p>Results</p> <p>Cystatin E/M was undetectable in media from all established melanoma cell lines examined, whereas strong immunobands were detected in two of five primary melanoma lines and in two of six lines derived from patients with metastatic disease. Among the four melanoma lines secreting cystatin E/M, the glycosylated form (17 kD) was predominant compared to the non-glycosylated form (14 kD). Legumain, cathepsin B and L were expressed and active in most of the cell lines, although at low levels in the melanomas expressing cystatin E/M. In the melanoma lines where cystatin E/M was secreted, cystatin C was generally absent or expressed at a very low level. When melanoma cells lacking secretion of cystatin E/M were transfected with pCST6, their intracellular legumain activity was significantly inhibited. In contrast, cathepsin B activity was not affected. Furthermore, invasion was suppressed in cystatin E/M over-expressing melanoma cell lines as measured by the transwell Matrigel assay.</p> <p>Conclusions</p> <p>These results suggest that the level of cystatin E/M regulates legumain activity and hence the invasive potential of human melanoma cells.</p