Cancer cell plasticity defines response to immunotherapy in cutaneous squamous cell carcinoma.

Immune checkpoint blockade (ICB) approaches have changed the therapeutic landscape for many tumor types. However, half of cutaneous squamous cell carcinoma (cSCC) patients remain unresponsive or develop resistance. Here, we show that, during cSCC progression in male mice, cancer cells acquire epithelial/mesenchymal plasticity and change their immune checkpoint (IC) ligand profile according to their features, dictating the IC pathways involved in immune evasion. Epithelial cancer cells, through the PD-1/PD-L1 pathway, and mesenchymal cancer cells, through the CTLA-4/CD80 and TIGIT/CD155 pathways, differentially block antitumor immune responses and determine the response to ICB therapies. Accordingly, the anti-PD-L1/TIGIT combination is the most effective strategy for blocking the growth of cSCCs that contain both epithelial and mesenchymal cancer cells. The expression of E-cadherin/Vimentin/CD80/CD155 proteins in cSCC, HNSCC and melanoma patient samples predicts response to anti-PD-1/PD-L1 therapy. Collectively, our findings indicate that the selection of ICB therapies should take into account the epithelial/mesenchymal features of cancer cells.

Sarcoidosis Induced by Atezolizumab Presenting With Xanthelasma Infiltration.

ABSTRACT: Sarcoidosis induced by anti-PD1 or anti-PDL1 agents such as atezolizumab has recently been reported. It has been suggested that the predilection of sarcoidosis to affect scars is due to the presence of antigens or foreign bodies that can serve as a stimulus for granuloma formation. However, to the best of our knowledge, sarcoidosis-specific skin lesions have not to date been reported involving xanthelasma. We report a patient who developed specific lesions of sarcoidosis infiltrating some xanthelasmata 6 months after starting treatment with atezolizumab. A 69-year-old woman was referred to the dermatology department for infiltration of xanthelasmata. The patient was being treated with atezolizumab for metastatic uterine carcinosarcoma. Cutaneous biopsy from an infiltrated xanthelasma and from still yellow, no infiltrated xanthelasma showed differing proportions of foamy histiocytes and sarcoid granulomas. On physical examination, erythemato-marronaceous papules clustered on both knees, and not previously detected by the patient, were observed. The biopsy showed sarcoid dermal granulomas with foreign bodies. A chest computerized tomography scan was consistent with intrathoracic involvement of sarcoidosis. Endobronchial ultrasound-guided transbronchial needle aspiration of a mediastinal lymphadenopathy showed epithelioid cell granulomas. Histopathologically, the foamy histiocytes of xanthelasma seem to be replaced by or evolve to epithelioid cells to form sarcoid granulomas. The possible pathogenic mechanism is discussed. Dermatologists and dermatopathologists should bear in mind that sarcoidosis can present as infiltration of pre-existing xanthelasmata.

FGFR Inhibition Overcomes Resistance to EGFR-targeted Therapy in Epithelial-like Cutaneous Carcinoma.

PURPOSE: Recurrent and/or metastatic unresectable cutaneous squamous cell carcinomas (cSCCs) are treated with chemotherapy or radiotherapy, but have poor clinical responses. A limited response (up to 45% of cases) to EGFR-targeted therapies was observed in clinical trials with patients with advanced and metastatic cSCC. Here, we analyze the molecular traits underlying the response to EGFR inhibitors, and the mechanisms responsible for cSCC resistance to EGFR-targeted therapy. EXPERIMENTAL DESIGN: We generated primary cell cultures and patient cSCC-derived xenografts (cSCC-PDXs) that recapitulate the histopathologic and molecular features of patient tumors. Response to gefitinib treatment was tested and gefitinib-resistant (GefR) cSCC-PDXs were developed. RNA sequence analysis was performed in matched untreated and GefR cSCC-PDXs to determine the mechanisms driving gefitinib resistance. RESULTS: cSCCs conserving epithelial traits exhibited strong activation of EGFR signaling, which promoted tumor cell proliferation, in contrast to mesenchymal-like cSCCs. Gefitinib treatment strongly blocked epithelial-like cSCC-PDX growth in the absence of EGFR and RAS mutations, whereas tumors carrying the E545K PIK3CA-activating mutation were resistant to treatment. A subset of initially responding tumors acquired resistance after long-term treatment, which was induced by the bypass from EGFR to FGFR signaling to allow tumor cell proliferation and survival upon gefitinib treatment. Pharmacologic inhibition of FGFR signaling overcame resistance to EGFR inhibitor, even in PIK3CA-mutated tumors. CONCLUSIONS: EGFR-targeted therapy may be appropriate for treating many epithelial-like cSCCs without PIK3CA-activating mutations. Combined EGFR- and FGFR-targeted therapy may be used to treat cSCCs that show intrinsic or acquired resistance to EGFR inhibitors.

WNT11-FZD7-DAAM1 signalling supports tumour initiating abilities and melanoma amoeboid invasion.

Melanoma is a highly aggressive tumour that can metastasize very early in disease progression. Notably, melanoma can disseminate using amoeboid invasive strategies. We show here that high Myosin II activity, high levels of ki-67 and high tumour-initiating abilities are characteristic of invasive amoeboid melanoma cells. Mechanistically, we find that WNT11-FZD7-DAAM1 activates Rho-ROCK1/2-Myosin II and plays a crucial role in regulating tumour-initiating potential, local invasion and distant metastasis formation. Importantly, amoeboid melanoma cells express both proliferative and invasive gene signatures. As such, invasive fronts of human and mouse melanomas are enriched in amoeboid cells that are also ki-67 positive. This pattern is further enhanced in metastatic lesions. We propose eradication of amoeboid melanoma cells after surgical removal as a therapeutic strategy.

Histopathological Features of Subcutaneous Sarcoidosis.

Only a few series of patients with systemic sarcoidosis and specific subcutaneous lesions have been reported. We reviewed our patients with systemic sarcoidosis with specific subcutaneous lesions to analyze their histopathological features and their relationship with clinical features of the systemic disease. Patients with systemic sarcoidosis with predominantly subcutaneous sarcoid granulomas diagnosed between 1980 and 2016 in Bellvitge University Hospital were enrolled. We also analyzed patients with clinically and histopathologically identical lesions in whom a diagnosis of systemic sarcoidosis could not be made during follow-up. Twenty-eight patients with systemic sarcoidosis presented specific subcutaneous lesions (23 women and 5 men, mean age 55.64 SD 12.26 years). Dermal involvement was observed in 10 cases, always discrete and limited to deep reticular dermis. The distribution of the granulomatous infiltrate was lobular in 7 cases and lobular and septal in 21. Fibrosis was observed in 21 cases. There were no significant differences in persistence of lesions or persistence of systemic disease activity when comparing patients with and without fibrosis. In conclusion, fibrosis is a frequent finding in subcutaneous sarcoidosis, and although it may be intense, it is not associated with pulmonary fibrosis or with >2 years of persistence of systemic sarcoidosis activity.

T-Type Calcium Channels as Potential Therapeutic Targets in Vemurafenib-Resistant BRAFV600E Melanoma.

Melanoma is a malignant neoplasia that is highly resistant to chemotherapy and radiotherapy and is associated with poor prognosis in advanced stage. Targeting melanoma that harbors the common BRAFV600E mutation with kinase inhibitors, such as vemurafenib, reduces tumor burden, but these tumors frequently acquire resistance to these drugs. We previously proposed that T-type calcium channel (TTCC) expression may serve as a biomarker for melanoma progression and prognosis, and we showed that TTCC blockers reduce migration and invasion rates because of autophagy blockade only in BRAFV600E-mutant melanoma cells. Here, we demonstrated that high expression of the TTCC Cav3.1 isoform is related to autophagic status in vemurafenib-resistant BRAFV600E-mutant melanoma cells and human biopsies, and in silico analysis revealed an enrichment of Cav3.1 expression in post-treatment melanomas. We also demonstrated that the TTCC blocker mibefradil induces apoptosis and impairs migration and invasion via inhibition of autophagy in resistant melanoma cells and mouse xenograft models. Moreover, we identified an association between PTEN status and Cav3.1 expression in these cells as a marker of sensitivity to combination therapy in resistant cells. Together, our results suggest that TTCC blockers offer a potential targeted therapy in resistant BRAFV600E-mutant melanoma and a therapeutic strategy to reduce progression toward BRAF inhibitor resistance.

PDGFR-induced autocrine SDF-1 signaling in cancer cells promotes metastasis in advanced skin carcinoma.

Advanced and undifferentiated skin squamous cell carcinomas (SCCs) exhibit aggressive growth and enhanced metastasis capability, which is associated in mice with an expansion of the cancer stem-like cell (CSC) population and with changes in the regulatory mechanisms that control the proliferation and invasion of these cells. Indeed, autocrine activation of PDGFRα induces CSC invasion and promotes distant metastasis in advanced SCCs. However, the mechanisms involved in this process were unclear. Here, we show that CSCs of mouse advanced SCCs (L-CSCs) express CXCR4 and CXCR7, both receptors of SDF-1. PDGFRα signaling induces SDF-1 expression and secretion, and the autocrine activation of this pathway in L-CSCs. Autocrine SDF-1/CXCR4 signaling induces L-CSC proliferation and survival, and mediates PDGFRα-induced invasion, promoting in vivo lung metastasis. Validation of these findings in patient samples of skin SCCs shows a strong correlation between the expression of SDF1, PDGFRA, and PDGFRB, which is upregulated, along CXCR4 in tumor cells of advanced SCCs. Furthermore, PDGFR regulates SDF-1 expression and inhibition of SDF-1/CXCR4 and PDGFR pathways blocks distant metastasis of human PD/S-SCCs. Our results indicate that functional crosstalk between PDGFR/SDF-1 signaling regulates tumor cell invasion and metastasis in human and mouse advanced SCCs, and suggest that CXCR4 and/or PDGFR inhibitors could be used to block metastasis of these aggressive tumors.

Specific Skin Lesions of Sarcoidosis Located at Venipuncture Points for Blood Sample Collection.

It has been suggested that the predilection of sarcoidosis to affect scars is due to the presence of antigens or foreign bodies that can serve as a stimulus for granuloma formation. Several patients with sarcoidosis-specific skin lesions in venous puncture sites have been reported. However, in these patients the pathogenesis of the cutaneous lesions is not clear because the presence of foreign bodies is not to be expected. Our objective was to describe 3 patients who developed specific lesions of sarcoidosis in areas of venipuncture and to discuss their possible pathogenesis. The database of the Sarcoid Clinic of Bellvitge Hospital (an 800-bed university referral center providing tertiary care to approximately 1 million people in Barcelona, Spain) was reviewed to detect those patients with specific cutaneous lesions of systemic sarcoidosis in areas of venipuncture. Three patients with biopsy-proven specific cutaneous lesions of systemic sarcoidosis in areas of venipuncture for blood collection were detected (3 women, mean age 56 years). In one case, the histopathological image shows the hypothetical path of a needle through the skin. In 2 cases, an amorphous birefringent material was detected under polarized light. This material was consistent with silicone. In patients who are developing sarcoidosis, the smallest amount of oil used as lubricant in the needle for sample blood collection may induce the formation of granulomas. In addition to exploring scars, it is advisable to explore the cubital folds to detect specific cutaneous lesions of sarcoidosis.

Evolution of cutaneous leishmaniasis in the last 30 years in a tertiary hospital of the European Mediterranean coast.

BACKGROUND: Although with a lower incidence than in other geographic areas, leishmaniasis is also endemic on the European Mediterranean coast. However, there are few studies on the clinical features of cutaneous lesions of leishmaniasis in Europe. Our objective was to review the clinical features of cutaneous leishmanial lesions in our European Mediterranean population in the last 30 years and compare the clinical features of immunosuppressed and nonimmunosuppressed patients. METHODS: The clinical features of cutaneous lesions of leishmaniasis diagnosed between 1987 and 2016 at Bellvitge Hospital in Barcelona, Spain, were retrospectively analyzed. RESULTS: Cutaneous lesions of leishmaniasis were diagnosed in 68 patients (40 male and 28 female, mean age 53.60 years, SD 19.68). Thirteen patients were immunosuppressed because of acquired immune deficiency syndrome (AIDS) (7), renal transplantation (1), lymphoma (1), and anti-TNF agents (4). Our immunosuppressed patients had more lesions (3.33 vs. 1.80, P = 0.021), with greater maximum diameter (33.00 vs. 13.33 mm, P = 0.001), and their lesions were more frequently disseminated (P = 0.008). Visceral leishmaniasis was observed only in immunosuppressed patients. Patients treated with anti-TNF drugs developed unusually large skin lesions with crusted, eroded surfaces and without a tendency to spontaneous remission. CONCLUSION: With the widespread use of anti-TNF agents, an increase in severe forms of leishmaniasis can be expected. The development of persistent, crusted, or eroded erythematous-brownish plaques in patients treated with anti-TNF drugs who live or had traveled to endemic areas of Leishmania infection warrants consideration of a diagnosis of cutaneous leishmaniasis.

Intravascular (blood vessel) histiocytosis with haemophagocytosis.

AIMS: Many types of intravascular lymphohistiocytic proliferation have been described recently; this was previously an unnoticed or misinterpreted phenomenon. Intralymphatic lymphohistiocytic aggregates are relatively common, and include benign, malignant and indeterminate conditions. In contrast, all non-endothelial proliferations in the lumina of blood vessels have been interpreted so far as malignant. Herein, we present three cases of histiocytic proliferations in the lumen of blood vessels associated with intracytoplasmic granulocyte debris (haemophagocytosis), a previously undescribed entity. METHODS AND RESULTS: We identified three patients from two institutions with similar cutaneous lesions, both clinically and microscopically. Information regarding clinical history, histological features and immunoprofiles were obtained. The three cases presented intravascular histiocytosis with haemophagocytosis involving blood vessels of the dermis, a process that may be representative of a new entity. The patients were two women and one man who presented a symmetrical reticulated erythema with a tendency to involve the skin of the breasts. The lesions were indolent, did not ulcerate and followed a benign course. CONCLUSION: This seemingly novel condition is characterized by the presence of histiocytic cells inside blood vessels, where they have not been described previously as an entity. The most reasonable explanation for this process is an origin from the non-classical subset of monocytes that 'patrol' the inner face of blood vessels acting as macrophages. The existence of this entity should be kept in mind to avoid overdiagnosis of malignancy.

Histopathological Features of Orofacial Granulomatosis.

Orofacial granulomatosis (OFG) is characterized by granulomatous inflammation in the orofacial region. Although several series have been reported, biopsy has not been performed in all cases and the histopathological features have not been extensively evaluated. Our purpose was to analyze the histopathological features of our patients with OFG. Twenty-two patients diagnosed with OFG at Bellvitge Hospital (Barcelona, Spain) from 1985 to 2010 were included in the study. All of our patients (14 men and 8 women; mean age 46.77 years, SD 13.61) presented with labial swelling, involving the upper lip in 13 cases and the lower lip in 9 at presentation. Fissured tongue was observed in 9 cases. Three patients suffered facial palsy. Granulomas were observed in 16 patients. All patients showed a perivascular, lymphohistiocytic inflammatory infiltrate with prominent plasma cells in 21 cases. In 5 cases, mast cells were easily observed. In 13 patients, an interstitial infiltrate was also present. All cases showed dilated lymphatic channels, and 19 edema of the lamina propria or the dermis. Perilymphatic granulomas were observed in 12 cases, intralymphatic granulomas in 2, and intralymphatic histiocytes in 2. In conclusion, loose epithelioid cells or lymphonodular granulomas were observed in 73% of our patients. Although none of our patients developed Crohn disease, OFG is histopathologically similar to cutaneous lesions of Crohn disease. The perilymphatic disposition of granulomas and the presence in some cases of intralymphatic histiocytes or intralymphatic granulomas may explain the dilatation of lymphatic vessels and the development of edema.

Cancer Stem-like Cells Act via Distinct Signaling Pathways in Promoting Late Stages of Malignant Progression.

Cancer stem-like cells (CSC) play key roles in long-term tumor propagation and metastasis, but their dynamics during disease progression are not understood. Tumor relapse in patients with initially excised skin squamous cell carcinomas (SCC) is characterized by increased metastatic potential, and SCC progression is associated with an expansion of CSC. Here, we used genetically and chemically-induced mouse models of skin SCC to investigate the signaling pathways contributing to CSC function during disease progression. We found that CSC regulatory mechanisms change in advanced SCC, correlating with aggressive tumor growth and enhanced metastasis. ß-Catenin and EGFR signaling, induced in early SCC CSC, were downregulated in advanced SCC. Instead, autocrine FGFR1 and PDGFRα signaling, which have not been previously associated with skin SCC CSC, were upregulated in late CSC and promoted tumor growth and metastasis, respectively. Finally, high-grade and recurrent human skin SCC recapitulated the signaling changes observed in advanced mouse SCC. Collectively, our findings suggest a stage-specific switch in CSC regulation during disease progression that could be therapeutically exploited by targeting the PDGFR and FGFR1 pathways to block relapse and metastasis of advanced human skin SCC.

Specific cutaneous involvement in Whipple disease.

Cutaneous lesions in Whipple disease (WD) are infrequent, and the histological findings are usually nonspecific. Specific cutaneous lesions have rarely been described and usually involve the subcutaneous fat. We report a patient diagnosed with WD, who developed multiple small subcutaneous nodules after antibiotic treatment was administered. In addition to septal panniculitis, the cutaneous biopsy showed a mild granulomatous dermal reaction with PAS-positive macrophages characteristic of WD. A positive polymerase chain reaction in the cutaneous sample confirmed the presence of Tropheryma whipplei in the skin. Dermatopathologists should be aware that not only subcutaneous lesions but also dermal lesions may exhibit specific findings of WD.

Epigenetic disruption of cadherin-11 in human cancer metastasis.

Little is known about the molecular events occurring in the metastases of human tumours. Epigenetic alterations are dynamic lesions that change over the natural course of the disease, and so they might play a role in the biology of cancer cells that have departed from the primary tumour. Herein, we have adopted an epigenomic approach to identify some of these changes. Using a DNA methylation microarray platform to compare paired primary tumour and lymph node metastatic cell lines from the same patient, we observed cadherin-11 promoter CpG island hypermethylation as a likely target of the process. We found that CDH11 DNA methylation-associated transcriptional silencing occurred in the corresponding lymph node metastases of melanoma and head and neck cancer cells but not in the primary tumours. Using in vitro and in vivo cellular and mouse models for depleted or enhanced CDH11 activity, we also demonstrated that CDH11 acts as an inhibitor of tumour growth, motility and dissemination. Most importantly, the study of CDH11 5'-CpG island hypermethylation in primary tumours and lymph node metastases of cancer patients showed this epigenetic alteration to be significantly confined to the disseminated cells. Overall, these results indicate the existence of metastasis-specific epigenetic events that might contribute to the progression of the disease.