Immunotherapy for keratinocyte cancers. Part II: Identification and management of cutaneous side effects of immunotherapy treatments

Caveolin-1 modulates cisplatin sensitivity in oral squamous cell carcinoma through ferroptosis

OBJECTIVE

Cisplatin-based chemotherapy is widely used for the treatment of oral squamous cell carcinoma (OSCC), but drug resistance and decreased sensitivity often occur during the treatment, greatly weakening its therapeutic effect. Caveolin-1 (CAV1), a protein related to ferroptosis, is involved in regulating the resistance and sensitivity of various tumor chemotherapies. This study aims to investigate whether CAV1 can regulate the sensitivity of OSCC to cisplatin through ferroptosis.

METHODS

Through bioinformatics analysis, we analyzed the expression of CAV1 in OSCC and its impact on prognosis analyzed the relationship between CAV1 and tumor immune infiltration, and verified the expression of CAV1 in OSCC through immunohistochemistry experiments. We silenced the expression of CAV1 in OSCC cells through lentiviral transfection and evaluated the cell migration and invasion abilities through wound healing and Transwell assays, respectively. CCK8 assay was used to assess the sensitivity of cells to cisplatin, and ferroptosis-related biochemical marker changes were measured. Western blot was performed to detect the expression of ferroptosis-related proteins.

RESULTS

The results revealed a high expression of CAV1 in OSCC, and its high expression predicted poor prognosis in OSCC. CAV1 is associated with drug metabolism pathways in OSCC, and its expression affects the infiltration levels of various immune cells in tumors. Further experiments indicated that CAV1 can inhibit ferroptosis and cisplatin sensitivity in cancer cells, promoting their migration and invasion.

CONCLUSION

CAV1 promotes the progression of OSCC and can affect the sensitivity of cisplatin by regulating cellular ferroptosis.

An Adverse Double-Hit by Pembrolizumab: A Case Report of Bullous Pemphigoid and Pneumonitis

Immune checkpoint inhibitors like pembrolizumab represent a modern approach to the management of various malignancies, including non-small cell lung cancer. The therapeutic activity of immunotherapy is exerted by the activation of immune cells against the tumor cells. However, systemic activation of the immune system can lead to the development of autoimmune complications known as immune-related adverse events. A combination of rare immune-related adverse events is occasionally observed simultaneously in the same patient. We present the case of a 66-year-old male with squamous non-small cell lung carcinoma who presented to the emergency department with dyspnea and respiratory failure. Imaging findings were consistent with pulmonary embolism and nonspecific interstitial pneumonitis. One month before this event, he was diagnosed with bullous pemphigoid following 21 cycles of treatment with pembrolizumab. The radiological findings, the lack of response to antibiotics, the negative microbiological workup, and the excellent response to corticosteroids established the diagnosis of pembrolizumab-induced pneumonitis. The combination of bullous pemphigoid and pneumonitis secondary to pembrolizumab is rare; only a few case reports exist in the literature. Hence, this case highlights the possibility of multiple immune-related adverse events in the same patient. The exclusion of infectious diseases and other immunologic disorders with a similar clinical presentation is necessary to make the final diagnosis of immune-related adverse events and start the appropriate treatment. Serology, histopathology, and direct immunofluorescence aid to the diagnosis of immune-related bullous pemphigoid; the differential diagnosis includes other pemphigoid or lichenoid diseases, Stevens-Johnson syndrome/toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms. Imaging, microbiological testing, and bronchoscopy (if possible) confirm the diagnosis of immune-related pneumonitis, which should be differentiated from acute coronary syndrome, cardiogenic pulmonary edema, pulmonary embolism, tumor progression, and lower respiratory tract infections (especially Pneumocystis jirovecii pneumonia in immunocompromised patients). An interdisciplinary approach is necessary for the management of these cases.

Distinct sets of molecular characteristics define tumor-rejecting neoantigens

Challenges in identifying tumor-rejecting neoantigens limit the efficacy of neoantigen vaccines to treat cancers, including cutaneous squamous cell carcinoma (cSCC). A minority of human cSCC tumors shared neoantigens, supporting the need for personalized vaccines. Using a UV-induced mouse cSCC model which recapitulated the mutational signature and driver mutations found in human disease, we found that CD8 T cells constrain cSCC. Two MHC class I neoantigens were identified that constrained cSCC growth. Compared to the wild-type peptides, one tumor-rejecting neoantigen exhibited improved MHC binding and the other had increased solvent accessibility of the mutated residue. Across known neoantigens that do not impact MHC binding, structural modeling of the peptide/MHC complexes indicated that increased solvent accessibility, which will facilitate TCR recognition of the neoantigen, distinguished tumor-rejecting from non-immunogenic neoantigens. This work reveals characteristics of tumor-rejecting neoantigens that may be of considerable importance in identifying optimal vaccine candidates in cSCC and other cancers.