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Tumor Discovery Choroid plexus tumors: Benign to malignant

4.3.2. NK cell therapy and dendritic cell vaccines B7H3-specific, and HER2-specific, CAR CD4+ and CD8+

Another set of immunotherapy approaches involves the T cells [148-150] . In pre-clinical trials using murine models,
use of NK cells and dendritic cells, both of which play key several noteworthy adoptive T-cell transfer techniques
roles in T-cell activation. NK cells are apt at recognizing with translational potential have been investigated. One
of the techniques involves injecting T Ag-specific donor
tumors despite reduced or eliminated MHC-I expression CD8+ T cells into transgenic mice expressing SV 40
and antigen presentation. They have an upstream oncogene after whole-body radiation administration.
recruitment role in type 1 dendritic cells and CD8+ T The use of the technique resulted in rapid, high-level T
cells, thus promoting cancer immunity to overcome the cell accumulation within the brain, elimination of CPC
oncoprotective TMEs that sustain and promote tumor tumors, persistence of T cells at tumor sites, and prevention
growth and proliferation [138-141] . While most studies focus of tumor recurrence [151,152] . A study by Cozza et al. further
on glioblastomas, which are the most aggressive and demonstrated that intraperitoneal injection of anti-CD40
malignant primary brain tumors in adults, these therapies IgG prior to CD8+ T cell injection achieved comparable
may soon be applied to CPTs. NK cells are not only levels of T-cell accumulation, CPT elimination, and
endogenously found in the choroid plexus but can also significantly extended survival in the absence of radiation
access the brain through the choroid plexus itself [124,142,143] . treatment. However, lower T cell accumulation and higher
Similarly, while the use of dendritic cell vaccines has rates of tumor recurrence were reported [153] .
not explicitly been studied in the context of choroid
plexus neoplasms, several approaches are being tested 4.3.4. Heat-shock protein and oncometabolism
in order to exploit type 1 dendritic cells in anti-tumor Recent evidence has highlighted the potential antitumoral
immunotherapies of other CNS tumors with some modest activity of heat-shock protein 70 (Hsp70), a molecular
success, opening the possibility for this technology to be chaperone. Hsp70 has the ability to deliver tumor-
applied in the near future for treating CPTs [144] . associated peptides to antigen-presenting cells for

4.3.3. Immune checkpoint therapy and adoptive T-cell subsequent presentation of these antigens via major
+
transfer histocompatibility class I to CD8 T-lymphocytes, thereby
inducing a tumor-specific immune response [154] . Shevtsov
Similar to the above-mentioned treatments, the use of et al. conducted a study utilizing immunomodulation
immune checkpoint modulators and adoptive T-cell via recombinant Hsp70 in the treatment of malignant
transfers, such as CAR-T therapy, for CPTs is sparse brain tumors in pediatric patients, one of whom had
despite the growing number of emerging treatments choroid plexus carcinoma and had only a partial response
for other cancer types. However, ongoing investigations to treatment with delayed-type hypersensitivity [155] .
are exploring key anticancer immune checkpoint Furthermore, heat-shock protein inhibition has shown the
players [145,146] . At present, there are four clinical trials potential to overcome thermo-resistance during PTT [111] .
investigating immunotherapies against CPTs. Among Further investigation is warranted to apply this technology
these clinical trials, one phase 2 study evaluates the efficacy to CPTs. Due to their highly vascularized nature; these
of immune checkpoint inhibitor (ICI) nivolumab, a tumors are theoretically well-suited for an immune cell-
monoclonal antibody targeting the programmed death-1 mediated approach.
(PD-1) receptor expressed on the surface of activated Another novel approach to manipulate TME is
human lymphocytes [147] . Another recent study focused oncometabolism, which aims to modify the local metabolic
on PD-1, utilizing functionalized biomimetic particles activity to restrict the growth or induce the destruction of
and combining the blockade approach with photothermal tumors. To the best of our knowledge, no clinical trials
ablation to enhance immunotherapy (although the focus have been conducted to treat CPTs using oncometabolism
here was on colorectal cancer) [125] . approach. However, there are several ongoing or completed
Adoptive T-cell therapy using CAR-T-cells is another clinical trials investigating the use of oncometabolism in
promising approach for treating brain tumors. These CAR- the treatment of other malignant brain tumors [156] .
T-cells are engineered to target tumor-specific neoantigens,
independent of major histone compatibility presentation 4.3.5. CPT biomarkers
of these antigens. There are three ongoing phase I clinical Precision immunotherapy requires sensitive and specific
trials, all evaluating CAR-T-cell therapies delivered biomarkers for each tumor group and subgroup. Some
through an indwelling catheter into either the tumor promising biomarkers have been identified as diagnostic
resection cavity or ventricular system in pediatric and and therapeutic targets for CPTs. Kir7.1, an inward rectifier
young adult patients. The trials involve EGFR806-specific, potassium channel, and stanniocalcin-1, a homodimeric

Volume 2 Issue 2 (2023) 8 https://doi.org/10.36922/td.1057