Interleukin-2 and Tretinoin for Myeloproliferative Neoplasms and to Target Type 1 Calreticulin-Driven Neoplasms: Advancements in Immune Regenerative Medicine.

Stem cells, also known as progenitor cells, can differentiate into specialized cells for specific tissues. Genetic mutations and epigenetic changes may cause normal stem cells to become cancer-initiating cells. Research indicates that cells acquiring a mutation for myeloproliferative neoplasm (MPN) are likely to be long-term hematopoietic stem cells (LT-HSCs) at the top of the hematopoietic hierarchy. Natural killer (NK) cells play a crucial role in combating cancer by targeting and eliminating cancer stem cells (CSCs) while promoting their maturation. NK cells do this through direct lysis of CSCs or by releasing cytokines like interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α), which inhibit tumor growth and metastasis by driving differentiation of CSCs. Interleukin-2 (IL-2) enhances the activity of CD4+ and CD8+ T cells and boosts NK cell cytotoxicity. This study highlights a case of MPN with a more clinically aggressive Type 1 calreticulin (CALR) mutation, where a combination of low-dose IL-2 immunotherapy and targeted therapy with oral tretinoin (all-trans retinoic acid, ATRA, a vitamin A derivative) improved immune cells, particularly NK-cell-mediated destruction of malignant cells, reduced CALR mutation levels to undetectable, and alleviated disease symptoms. The aim is to offer a new, low-toxicity personalized treatment strategy that eradicates cancer-initiating stem cells, reduces side effects, and provides an option for patients with limited conventional therapy alternatives.