Table 2 Summary of the facts that link PTEN loss in cancer to immunosuppression
From: Is there a causal link between PTEN deficient tumors and immunosuppressive tumor microenvironment?
Function | Facts |
|---|---|
PTEN’s role in tumor suppression | * PTEN deficiency is observed in nearly 40% of glioblastoma [14] * PTEN contributes to repair of DNA damage via the homologous recombination pathway [7] * PTEN deficiency is associated with malignant transformation, chemotherapy resistance and reduced survival [8,9,10,11] |
Tumors with PTEN deficiency have dysregulated infiltration of immune cells | * High levels of MDSCs [27] and Tregs [29] in the TME of PTEN deficient tumors * Reduced infiltration of CD4+, CD8+ and NK cells [23, 25] and reduced lysing activities of cytotoxic T lymphocytes depending on the granzyme and perforin depletion [25, 26] |
PTEN’s role in type 1 IFN pathway | * Type 1 IFN pathway promotes anti-tumor immunity [49] * PTEN is required for activation of STING mediated induction of interferon alpha/beta gene expression [67] |
Potential ways in which PTEN deficient tumors can be targeted by immunotherapies | * Activation of interferon alpha/beta signaling [89, 91] * Engineered PTENα expressing oncolytic viruses can enhance the development of antitumor immunity [96] |