Glioma

Gliomas are primary tumors that originate in the brain parenchyma. There are different types of glioma, which differ in terms of cellular characteristics, location, and severity. Some gliomas do not show any symptoms, but when they do, they indicate that the brain or spinal cord is being compressed. These tumors grow inside the brain parenchyma and often mix with normal brain tissue, making them difficult to remove surgically and characterized by short survival, high recurrence rates, high disability rates, and high mortality rates.

Gliomas include astrocytomas, brainstem gliomas, ventricular meningiomas, mixed gliomas, oligodendrogliomas, glioblastoma multiforme, and optic gliomas. Nearly half of all primary brain tumors are astrocytomas. Malignant gliomas are the most serious form of malignant astrocytoma.

Treatment of gliomas includes surgical resection and radiation therapy, and for some tumors, chemotherapy may be given and medication may be required to reduce the signs and symptoms caused by the tumor. In the physiological state, immune checkpoint molecules act as an immunomodulatory mechanism to suppress cytotoxic T-cell function. In the tumor microenvironment, the variant immune checkpoint signaling pathway is an important immune escape mechanism. Alfa Cytology is actively helping researchers to carry out more in-depth functional studies of multiple targets.

• Programmed death-1/programmed death-ligand 1 (PD1/PDL1)

PDL1 is mainly expressed in glioma cells and microglia, and PDL1 is in tumor-infiltrating lymphocytes. Changes in PDL1 expression correlate with the pathological grade of gliomas. Studies have shown that PDL1 expression levels are significantly higher in IDH wild-type patients than in IDH mutant patients in glioblastoma and that changes in PDL1 expression are negatively correlated with the prognosis of glioma patients.

• Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4)

CTLA-4 is the first immunoglobulin superfamily member to be identified and the first immunomodulatory molecule to be used in targeted therapy. It is expressed on activated T cells or regulatory T cells (Treg), mainly on activated T cells, and binds to the CTLA-4 ligands CD80 and CD86 on the surface of antigen-presenting cells, inhibiting the T cell co-stimulatory signaling pathway. Changes in CTLA-4 expression on the surface of CD4⁺ and CD8⁺ T cells in the peripheral blood of glioblastoma patients were negatively correlated with prognosis.

• B7-H4

B7-H4 is a member of the B7 family of immune checkpoints and is barely expressed in normal tissues, but is highly expressed in many malignant tumors such as gliomas. In addition to PDL1 (B7-H1), we are also helping our customers with studies including B7-H3, B7-H4, and B7-H5 (VISTA).

• Indoleamine-2, 3-dioxygenase (IDO)

IDO is a tryptophan catabolic enzyme expressed mainly in a variety of tumor cells and dendritic cells (DCs). Although it is not a typical immune checkpoint molecule, it inhibits T cell activation and suppresses natural killer (NK) cell function. Under physiological conditions, the brain parenchyma does not express IDO, whereas most glioblastoma and low-grade glioma patients express IDO, and changes in IDO expression are negatively correlated with the prognosis of glioblastoma patients. Animal models have shown that targeted IDO drugs are effective in the treatment of gliomas.

Immunotherapy is undoubtedly a key and topical issue in glioma treatment research and is an important addition to current and future clinical treatment options for glioma. In addition, Alfa Cytology is also helping customers to actively explore further possibilities regarding combination therapies and vaccines in glioma research. Please feel free to contact us for more information.