Pexidartinib synergize PD-1 antibody through inhibiting treg infiltration by reducing TAM-derived CCL22 in lung adenocarcinoma

There is a crosstalk between Tumor-associated macrophages (TAM) and tumor-infiltrating T cells in tumor environment. TAM could inhibit the activity of cytotoxic T cells; TAM could also regulate the composition of T cells in tumor immune environment. The combination therapy for TAM and tumor infiltrated T cells has been widely noticed, but the crosstalk between TAM and tumor infiltrated T cells remains unclear in the process of combination therapy. We treated lung adenocarcinoma tumor models with pexidartinib, which targets macrophage colony stimulating factor receptor (M-CSFR) and c-kit tyrosine kinase, to inhibited TAM. Pexidartinib inhibited the ratio of macrophages in the tumor and also altered macrophage polarization. In addition to reprogram TAM, pexidartinib also changed the composition of tumor-invasive T cells. After pexidartinib treatment, the total number of T cells, CD8⁺ T cells and Treg cells were all decreased, the ratio of CD8+T/Treg increased significantly. According to the analysis of cytokines and chemokines during the treatment of pexidartinib, CCL22, as a chemokine for Treg recruitment, significantly decreased after the treatment of pexidartinib. Base on the above observation, the combination of pexidartinib and PD-1 antibody were used in the treatment of lung adenocarcinoma subcutaneous tumor model, the combination therapy has significantly improved the efficacy of tumor treatment compared with the monotherapy. Meanwhile, compared with pexidartinib monotherapy, the combination treatment further switches the polarization status of tumor-associated macrophages. In summary, our results showed that the combination of pexidartinib and PD-1 antibody showed a synergy and significantly improved the anti-tumor efficacy, through pexidartinib increasing CD8T/Treg ratio by reducing TAM-derived CCL22.

Uterine sarcoma Part II-Uterine endometrial stromal sarcoma: The TAG systematic review

Endometrial stromal tumors are rare uterine tumors (<1%). Four main categories include endometrial stromal nodule, low-grade endometrial stromal sarcoma (LG-ESS), high-grade endometrial stromal sarcoma (HG-ESS), and uterine undifferentiated sarcoma (UUS). This review is a series of articles discussing the uterine sarcomas. LG-ESS, a hormone-dependent tumor harboring chromosomal rearrangement, is an indolent tumor with a favorable prognosis, but characterized by late recurrences even in patients with Stage I disease, suggesting the requirement of a long-term follow-up. Patients with HG-ESS, based on the identification of YWHAE-NUTM2A/B (YWHAE-FAM22A/B) gene fusion, typically present with advanced stage diseases and frequently have recurrences, usually within a few years after initial surgery. UUS is, a high-grade sarcoma, extremely rare, lacking a specific line of differentiation, which is a diagnosis of exclusion (the wastebasket category, which fails to fulfill the morphological and immunohistochemical criteria of translocation-positive ESS). Surgery is the main strategy in the management of uterine sarcoma. Due to rarity, complex biological characteristics, and unknown etiology and risk factors of uterine sarcomas, the role of adjuvant therapy is not clear. Only LG-ESS might respond to progestins or aromatase inhibitors.

Critical role of HMGA proteins in cancer cell chemoresistance

The high-mobility group A (HMGA) proteins are frequently overexpressed in human malignancies and correlate with the presence of metastases and reduced patient survival. Here, we highlight the main studies evidencing a critical role of HMGA in chemoresistance, mainly by activating Akt signaling, impairing p53 activity, and regulating the expression of microRNAs that target genes involved in the susceptibility of cancer cells to antineoplastic agents. Therefore, these studies account for the association of HMGA overexpression with patient poor outcome, indicating the impairment of HMGA as a fascinating perspective for effectively improving cancer therapy.