Gene-edited and -engineered stem cell platform drives immunotherapy for brain metastatic melanomas.

Oncolytic virus therapy has shown activity against primary melanomas; however, its efficacy in brain metastases remains challenging, mainly because of the delivery and immunosuppressive nature of tumors in the brain. To address this challenge, we first established PTEN-deficient melanoma brain metastasis mouse models and characterized them to be more immunosuppressive compared with primary melanoma, mimicking the clinical settings. Next, we developed an allogeneic twin stem cell (TSC) system composed of two tumor-targeting stem cell (SC) populations. One SC was loaded with oncolytic herpes simplex virus (oHSV), and the other SC was CRISPR-Cas9 gene-edited to knock out nectin 1 (N1) receptor (N1KO) to acquire resistance to oHSV and release immunomodulators, such as granulocyte-macrophage colony-stimulating factor (GM-CSF). Using mouse models of brain metastatic BRAFV600E/PTEN-/- and BRAFV600E/wt/PTEN-/- mutant melanomas, we show that locoregional delivery of TSCs releasing oHSV and GM-CSF (TSC-G) activated dendritic cell- and T cell-mediated immune responses. In addition, our strategy exhibited greater therapeutic efficacy when compared with the existing oncolytic viral therapeutic approaches. Moreover, the TSCs composed of SC-oHSV and SCN1KO-releasing GM-CSF and single-chain variable fragment anti-PD-1 (TSC-G/P) had therapeutic efficacy in both syngeneic and patient-derived humanized mouse models of leptomeningeal metastasis. Our findings provide a promising allogeneic SC-based immunotherapeutic strategy against melanomas in the CNS and a road map toward clinical translation.

Next-generation immunotherapies for brain metastatic cancers.

Patients with extracranial tumors, like lung, breast, and skin cancers, often develop brain metastases (BM) during the course of their diseases and BM commonly represent the terminal stage of cancer progression. Recent insights in the immune biology of BM and the increasing focus of immunotherapy as a therapeutic option for cancer has prompted testing of promising biological immunotherapies, including immune cell-targeting, virotherapy, vaccines, and different cell-based therapies. Here, we review the pathobiology of BM progression and evaluate the potential of next-generation immunotherapies for BM tumors. We also provide future perspectives on the development and implementation of such therapies for brain metastatic cancer patients.

[Carotid body paraganglioma in a teenager. Case report]. / Paraganglioma del cuerpo carotídeo en adolescente. Reporte de caso.

BACKGROUND: Paragangliomas of the head and neck are neuroendocrine tumors. They have a low incidence (0.6%), are generally benign, have a poorly defined etiology, and multiple factors have been associated with their origin. Humans and other species living at high altitudes (>2000 m above sea level) are subjected to a relatively chronic hypoxia and there is a high prevalence of the development of carotid body hyperplasia and eventually paragangliomas. This disease is usually seen in patients in their 50s and in their 30s if there is a family history. CLINICAL CASE: We present the case of a 16 year-old female with acute pharyngitis and growing tumor located on the left side of the neck, without symptoms. A duplex Doppler ultrasound showed a solid nodular lesion on the left carotid bifurcation. A left lateral cervicotomy was performed, finding a highly vascularized tumor of 4 × 3 × 3 cm involving the common carotid from its middle third, the internal carotid up to the cranial base, and the external carotid to its upper third, and intimately related to the trachea, esophagus and cervical spine. The tumor was completely resected and the histopathological analysis corroborated the presence of paragangliomas. CONCLUSIONS: The publication of this case is relevant and of clinical interest due to the uncommon age of presentation and the fact that it should be considered as a diagnostic possibility.

Antecedentes: los paragangliomas de cabeza y cuello son tumores neuroendocrinos de baja incidencia (0.6%), en su mayor parte benignos, en cuyo origen se han involucrado múltiples factores. Los seres humanos y otras especies que viven a grandes alturas (por arriba de 2000 metros sobre el nivel del mar) son propensos a sufrir hipoxia crónica relativa, hiperplasia del cuerpo carotídeo y, eventualmente, paragangliomas. Este padecimiento aparece en la quinta década de la vida y en la tercera, en caso de presentación familiar. Caso clínico: se comunica el caso de una adolescente de 16 años de edad que un año antes tuvo faringitis aguda con tumor localizado en la cara lateral izquierda del cuello, de crecimiento gradual, sin ningún síntoma. El ultrasonido Doppler dúplex de cuello mostró una lesión nodular sólida sobre el trayecto de la bifurcación carotídea izquierda. Fue intervenida quirúrgicamente mediante cervicotomía lateral izquierda, en la cual se encontró una tumoración de aproximadamente 4 × 3 × 3 cm, sumamente vascularizada, que afectaba la carótida común desde su tercio medio, la carótida interna hasta la base del cráneo y la carótida externa hasta el tercio superior, con íntima relación con la tráquea, el esófago y la columna cervical. La tumoración se resecó en su totalidad, el estudio histopatológico corroboró los paragangliomas. Conclusiones: la edad de presentación es poco común, por lo que se considera relevante y de interés clínico comunicar este caso, toda vez que debe considerarse como posibilidad diagnóstica.