Screening Ion Channels in Cancer Cells

Ion channels are critical for cell development and maintaining cell homeostasis. The perturbation of ion channel function contributes to the development ...

University of Cincinnati College of Medicine

Most patients with metastatic melanoma show variable responses to radiation therapy and do not benefit from immune checkpoint inhibitors. Improved strategies for combination therapy that leverage potential benefits from radiation therapy and immune checkpoint inhibitors are critical.

Melanoma Cell Intrinsic GABA Receptor Enhancement Potentiates Radiation and Immune Checkpoint Inhibitor Response by Promoting Direct and T Cell-Mediated Antitumor Activity.

"Brain tumor is a bump in the road." Sheryl Crow a famous singer was quoted talking about her meningioma, a benign brain tumor that caused her to forget her lyrics. In this review, we focus on low-grade gliomas in adults and benign brain tumors, such as meningiomas, vestibular schwannomas, and pituitary tumors, since these individuals survive a long time and morbidity is a major issue.

Interdisciplinary Approaches to Survivorship with a Focus on the Low-grade and Benign Brain Tumor Populations.

RNA-based therapies offer unique advantages for treating brain tumors. However, tumor penetrance and uptake are hampered by RNA therapeutic size, charge, and need to be "packaged" in large carriers to improve bioavailability. Here, we have examined delivery of siRNA, packaged in 50-nm cationic lipid-polymer hybrid nanoparticles (LPHs:siRNA), combined with microbubble-enhanced focused ultrasound (MB-FUS) in pediatric and adult preclinical brain tumor models. Using single-cell image analysis, we show that MB-FUS in combination with LPHs:siRNA leads to more than 10-fold improvement in siRNA delivery into brain tumor microenvironments of the two models. MB-FUS delivery of Smoothened () targeting siRNAs reduces  protein production and markedly increases tumor cell death in the -activated medulloblastoma model. Moreover, our analysis reveals that MB-FUS and nanoparticle properties can be optimized to maximize delivery in the brain tumor microenvironment, thereby serving as a platform for developing next-generation tunable delivery systems for RNA-based therapy in brain tumors.

Single-cell analysis reveals effective siRNA delivery in brain tumors with microbubble-enhanced ultrasound and cationic nanoparticles.

Numerous studies have provided single-cell transcriptome profiles of host responses to SARS-CoV-2 infection. Critically lacking however is a datamine that allows users to compare and explore cell profiles to gain insights and develop new hypotheses. To accomplish this, we harmonized datasets from COVID-19 and other control condition blood, bronchoalveolar lavage, and tissue samples, and derived a compendium of gene signature modules per cell type, subtype, clinical condition, and compartment. We demonstrate approaches to probe these via a new interactive web portal (http://toppcell.cchmc.org/COVID-19). As examples, we develop three hypotheses: (1) a multicellular signaling cascade among alternatively differentiated monocyte-derived macrophages whose tasks include T cell recruitment and activation; (2) novel platelet subtypes with drastically modulated expression of genes responsible for adhesion, coagulation and thrombosis; and (3) a multilineage cell activator network able to drive extrafollicular B maturation via an ensemble of genes strongly associated with risk for developing post-viral autoimmunity.

Implicating Gene and Cell Networks Responsible for Differential COVID-19 Host Responses via an Interactive Single Cell Web Portal.

Numerous studies have provided single-cell transcriptome profiles of host responses to SARS-CoV-2 infection. Critically lacking however is a data mine that allows users to compare and explore cell profiles to gain insights and develop new hypotheses. To accomplish this, we harmonized datasets from COVID-19 and other control condition blood, bronchoalveolar lavage, and tissue samples, and derived a compendium of gene signature modules per cell type, subtype, clinical condition, and compartment. We demonstrate approaches to interacting with, exploring, and functional evaluating these modules via a new interactive web portal ToppCell (http://toppcell.cchmc.org/). As examples, we develop three hypotheses: (1) alternatively-differentiated monocyte-derived macrophages form a multicelllar signaling cascade that drives T cell recruitment and activation; (2) COVID-19-generated platelet subtypes exhibit dramatically altered potential to adhere, coagulate, and thrombose; and (3) extrafollicular B maturation is driven by a multilineage cell activation network that expresses an ensemble of genes strongly associated with risk for developing post-viral autoimmunity.

An interactive single cell web portal identifies gene and cell networks in COVID-19 host responses.

γ-aminobutyric acid or GABA is an amino acid that functionally acts as a neurotransmitter and is critical to neurotransmission. GABA is also a metabolite in the Krebs cycle. It is therefore unsurprising that GABA and its receptors are also present outside of the central nervous system, including in immune cells. This observation suggests that GABAergic signaling impacts events beyond brain function and possibly human health beyond neurological disorders. Indeed, GABA receptor subunits are expressed in pathological disease states, including in disparate cancers. The role that GABA and its receptors may play in cancer development and progression remains unclear. If, however, those cancers have functional GABA receptors that participate in GABAergic signaling, it raises an important question whether these signaling pathways might be targetable for therapeutic benefit. Herein we summarize the effects of modulating Type-A GABA receptor signaling in various cancers and highlight how Type-A GABA receptors could emerge as a novel therapeutic target in cancer.

Therapeutically leveraging GABA receptors in cancer.

Chemotherapy-induced thrombocytopenia (CIT) is a critical condition in which platelet counts are abnormally reduced following the administration of chemotherapeutic compounds. CIT poses a treatment conundrum to clinicians given the increased risk of spontaneous bleeding, obstacles to surgical management of tumors, and exclusion from clinical trials. Treatment of CIT involves the removal of the offending agent combined with platelet infusion or thrombopoietin agonist treatment. However, due to the autoimmune and infection risks associated with infusions, this treatment is only reserved for patients with critically low platelet counts. One potential solution for patients in the mid to low platelet count range is  leaf extract (CPLE). In this case, we report the novel use of CPLE as a method of bolstering platelet counts in a patient presenting with CIT. The patient was initiated on CPLE therapy consisting of 1 tablespoon twice daily with meals. Following CPLE treatment, the patient's platelet counts rebounded from less than 10,000/µL to 113,000/µL. This clinical vignette supports the use of CPLE in the clinical context of CIT when thrombopoietin agonists are not a viable option. The potential benefits of CPLE as a method for increasing platelet count deserve further exploration, especially as a treatment option for refractory patients or those ill-suited for other traditional thrombocytopenia therapies.

A Case Study Using Papaya Leaf Extract to Reverse Chemotherapy-Induced Thrombocytopenia in a GBM Patient.

Atypical teratoid rhabdoid tumor (ATRT) is a highly malignant embryonal tumor of the CNS, largely affecting pediatric patients, with exceedingly rare cases in adults at an estimated annual incidence of 1/1,000,000. We report a unique case of ATRT in a 43-year-old female patient who first presented with progressive focal headaches. Imaging revealed a sellar mass with suprasellar extensions, which was partially removed via a transsphenoidal resection. The tumor aggressively recurred just 1 month postoperatively. Her care team pursued a novel treatment plan by using a slightly modified COG ACNS 0332 regimen, which involved radiation, followed by 4 cycles of monthly chemotherapy including vincristine, cyclophosphamide, and cisplatin. Hematopoietic stem cells were collected between radiation and chemotherapy in the event that the patient required stem cell salvage therapy postadjuvant chemotherapy. The MRIs taken at 2 and 4 months postrecurrence indicated a substantial decrease in tumor volume, with corresponding clinical improvements to cranial nerve deficits. Given the scarcity of literature on adult cases of ATRT and the lack of a standard of care for these cases, discussing the efficacy of our patient's treatment plan may aid clinical decision making for adult ATRT cases.

Pearls & Oy-sters: Pivoting Treatment Regimens of Pediatric Atypical Teratoid Rhabdoid Tumors to Optimize Care in Adult ATRT: A Case Report.

Glioblastoma, or glioblastoma multiforme (GBM, WHO Grade IV), is a highly aggressive adult glioma. Despite extensive efforts to improve treatment, the current standard-of-care (SOC) regimen, which consists of maximal resection, radiotherapy, and temozolomide (TMZ), achieves only a 12-15 month survival. The clinical improvements achieved through immunotherapy in several extracranial solid tumors, including non-small-cell lung cancer, melanoma, and non-Hodgkin lymphoma, inspired investigations to pursue various immunotherapeutic interventions in adult glioblastoma patients. Despite some encouraging reports from preclinical and early-stage clinical trials, none of the tested agents have been convincing in Phase III clinical trials. One, but not the only, factor that is accountable for the slow progress is the blood-brain barrier, which prevents most antitumor drugs from reaching the target in appreciable amounts. Herein, we review the current state of immunotherapy in glioblastoma and discuss the significant challenges that prevent advancement. We also provide thoughts on steps that may be taken to remediate these challenges, including the application of ultrasound technologies.

Advances in Immunotherapy for the Treatment of Adult Glioblastoma: Overcoming Chemical and Physical Barriers.

The DNA alkylating agent temozolomide (TMZ), is the first-line therapeutic for the treatment of glioblastoma (GBM). However, its use is confounded by the occurrence of drug resistance and debilitating adverse effects. Previously, we observed that letrozole (LTZ), an aromatase inhibitor, has potent activity against GBM in pre-clinical models. Here, we evaluated the effect of LTZ on TMZ activity against patient-derived GBM cells.

Potentiation of temozolomide activity against glioblastoma cells by aromatase inhibitor letrozole.

Healthcare workers (HCWs) need to be vaccinated against COVID-19 because they care for vulnerable patients. Hesitation to receiving the COVID-19 vaccine stems from the argument of bodily autonomy, novel mRNA vaccine technology, and conspiracy theories. However, vaccinations may prevent thousands of hospitalizations and deaths. HCWs have previously complied with other required vaccinations to care for children, elderly, and immunocompromised patients. Yet, COVID-19 vaccination mandates in the healthcare setting have been faced with resistance and subsequent staffing shortages. As HCWs display their hesitation to the vaccine, the community loses trust in its efficacy and safety. Speculation on pharmaceutical profiteering has also contributed to vaccine mistrust. As the pandemic continues, the healthcare field must decide on a course of action: adhere to vaccination mandates and cope with decreased staffing, repeal vaccination mandates to recover staff, rely on personal protective equipment (PPE) alone for protection, or do nothing and expect survival through herd immunity. To date, the United States has chosen to mandate COVID-19 vaccinations for any healthcare worker employed by Medicare and/or Medicaid-accepting facilities, allowing allergy and religious exemptions. This COVID-19 vaccination mandate for HCWs ethically protects the vulnerable people who HCWs vow to care for.

COVID-19 Vaccine Mandates for Healthcare Professionals in the United States.

Glioblastoma (GBM) is the most common and aggressive malignant adult brain tumor. Significant effort has been directed to achieve a molecular subtyping of GBM to impact treatment. The discovery of new unique molecular alterations has resulted in a more effective classification of tumors and has opened the door to subtype-specific therapeutic targets. Morphologically identical GBM may have different genetic, epigenetic, and transcriptomic alterations and therefore different progression trajectories and response to treatments. With a transition to molecularly guided diagnosis, there is now a potential to personalize and successfully manage this tumor type to improve outcomes. The steps to achieve subtype-specific molecular signatures can be extrapolated to other neuroproliferative as well as neurodegenerative disorders.

Lessons learned from evolving frameworks in adult glioblastoma.

Integrative neuro-oncology for brain tumor patients.

Gliomas are the most prevalent neurological cancer in the USA and care modalities are not able to effectively combat these aggressive malignancies. Identifying new, more effective treatments require a deep understanding of the complex genetic variations and relevant pathway associations behind these cancers. Drawing connections between gene mutations with a responsive genetic target can help drive therapy selections to enhance patient survival. We have performed extensive molecular profiling of the Capicua gene (CIC), a tumor and transcriptional suppressor gene, and its mutation prevalence in reference to MAPK activation within clinical glioma tissue. CIC mutations occur far more frequently in oligodendroglioma (52.1%) than in low-grade astrocytoma or glioblastoma. CIC-associated mutations were observed across all glioma subtypes, and MAPK-associated mutations were most prevalent in CIC wild-type tissue regardless of the glioma subtype. MAPK activation, however, was enhanced in CIC-mutated oligodendroglioma. The totality of our observations reported supports the use of CIC as a relevant genetic marker for MAPK activation. Identification of CIC mutations, or lack thereof, can assist in selecting, implementing, and developing MEK/MAPK-inhibitory trials to improve patient outcomes potentially.

Article	Year
Melanoma Cell Intrinsic GABA Receptor Enhancement Potentiates Radiation and Immune Checkpoint Inhibitor Response by Promoting Direct and T Cell-Mediated Antitumor Activity. International journal of radiation oncology, biology, physics\| PubMed ID: 33289666	2021
Interdisciplinary Approaches to Survivorship with a Focus on the Low-grade and Benign Brain Tumor Populations. Current oncology reports\| PubMed ID: 33471214	2021
Single-cell analysis reveals effective siRNA delivery in brain tumors with microbubble-enhanced ultrasound and cationic nanoparticles. Science advances\| PubMed ID: 33931452	2021
Implicating Gene and Cell Networks Responsible for Differential COVID-19 Host Responses via an Interactive Single Cell Web Portal. bioRxiv : the preprint server for biology\| PubMed ID: 34127975	2021
An interactive single cell web portal identifies gene and cell networks in COVID-19 host responses. iScience\| PubMed ID: 34522848	2021
Therapeutically leveraging GABA receptors in cancer. Experimental biology and medicine (Maywood, N.J.)\| PubMed ID: 34649481	2021
A Case Study Using Papaya Leaf Extract to Reverse Chemotherapy-Induced Thrombocytopenia in a GBM Patient. Integrative cancer therapies\| PubMed ID: 34984951	2022
Pearls & Oy-sters: Pivoting Treatment Regimens of Pediatric Atypical Teratoid Rhabdoid Tumors to Optimize Care in Adult ATRT: A Case Report. Neurology\| PubMed ID: 35256482	2022
Advances in Immunotherapy for the Treatment of Adult Glioblastoma: Overcoming Chemical and Physical Barriers. Cancers\| PubMed ID: 35406398	2022
Potentiation of temozolomide activity against glioblastoma cells by aromatase inhibitor letrozole. Cancer chemotherapy and pharmacology\| PubMed ID: 36050497	2022
COVID-19 Vaccine Mandates for Healthcare Professionals in the United States. Vaccines\| PubMed ID: 36146503	2022
Lessons learned from evolving frameworks in adult glioblastoma. Handbook of clinical neurology\| PubMed ID: 36796938	2023
Integrative neuro-oncology for brain tumor patients. Journal of neuro-oncology\| PubMed ID: 37097501	2023
Capicua (CIC) mutations in gliomas in association with MAPK activation for exposing a potential therapeutic target. Medical oncology (Northwood, London, England)\| PubMed ID: 37291277	2023

Soma Sengupta

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