Adoptive cell therapy with chimeric antigen receptor (CAR) immunotherapy has made tremendous progress with five CAR T therapies approved by the US Food and Drug Administration for hematological malignancies. However, CAR immunotherapy in solid tumors lags significantly behind. Some of the major hurdles for CAR immunotherapy in solid tumors include CAR T cell manufacturing, lack of tumor-specific antigens, inefficient CAR T cell trafficking and infiltration into tumor sites, immunosuppressive tumor microenvironment (TME), therapy-associated toxicity, and antigen escape. CAR Natural Killer (NK) cells have several advantages over CAR T cells as the NK cells can be manufactured from pre-existing cell lines or allogeneic NK cells with unmatched major histocompatibility complex (MHC); can kill cancer cells through both CAR-dependent and CAR-independent pathways; and have less toxicity, especially cytokine-release syndrome and neurotoxicity. At least one clinical trial showed the efficacy and tolerability of CAR NK cell therapy. Macrophages can efficiently infiltrate into tumors, are major immune regulators and abundantly present in TME. The immunosuppressive M2 macrophages are at least as efficient as the proinflammatory M1 macrophages in phagocytosis of target cells; and M2 macrophages can be induced to differentiate to the M1 phenotype. Consequently, there is significant interest in developing CAR macrophages for cancer immunotherapy to overcome some major hurdles associated with CAR T/NK therapy, especially in solid tumors. Nevertheless, both CAR NK and CAR macrophages have their own limitations. This comprehensive review article will discuss the current status and the major hurdles associated with CAR T and CAR NK therapy, followed by the structure and cutting-edge research of developing CAR macrophages as cancer-specific phagocytes, antigen presenters, immunostimulators, and TME modifiers.

Numerous studies indicate that diets with a variety of fruits and vegetables decrease the incidence of severe diseases, like diabetes, obesity, and cancer. Diets contain a variety of bioactive compounds, and their features, like diverge scaffolds, and structural complexity make them the most successful source of potential leads or hits in the process of drug discovery and drug development. Recently, novel serine protease dipeptidyl peptidase-4 (DPP-4) inhibitors played a role in the management of diabetes, obesity, and cancer. This study describes the development of field template, field-based qualitative structure–activity relationship (SAR) model demonstrating DPP-4 inhibitors of natural origin, and the same model is used to screen virtually focused food database composed of polyphenols as potential DPP-4 inhibitors. Compounds’ similarity to field template, and novelty score “high and very high”, were used as primary criteria to identify novel DPP-4 inhibitors. Molecular docking simulations were performed on the resulting natural compounds using FlexX algorithm. Finally, one natural compound, chrysin, was chosen to be evaluated experimentally to demonstrate the applicability of constructed SAR model. This study provides the molecular insights necessary in the discovery of new leads as DPP-4 inhibitors, to improve the potency of existing DPP-4 natural inhibitors.

Diabetes mellitus is a severe health problem in Mexico, and its prevalence is increasing exponentially every year. Recently, DPP-4 (dipeptidyl peptidase-4) inhibitors have become attractive oral anti-hyperglycemic agents to reduce the pathology of diabetes. Gliptin’s family, such as sitagliptin, vildagliptin, and alogliptin, are in clinical use to treat diabetes mellitus but possess side effects. Therefore, there is a specific need to look for new therapeutic scaffolds (biomolecules). Garlic bulb is widely used as a traditional remedy for the treatment of diabetes. The garlic extracts are scientifically proven to control glucose levels in patients with diabetes, despite the unknown mechanism of action. The aim of the study is to investigate the antidiabetic effects of ultrasonication assisted garlic bulb extract. To achieve this, in-vitro assays such as DPP-4 inhibitory and antioxidant activities were investigated. Further, functional group analysis using FTIR and identification of phytochemicals using mass spectrometry analysis was performed. The results showed that 70.9 µg/mL of garlic bulb extract inhibited 50% DPP-4 activity. On top of that, the garlic extract exhibited a 20% scavenging activity, equivalent to 10 µg/mL of ascorbic acid. Molecular docking simulations on identified phytochemicals using mass spectrometry revealed their potential binding at the DPP-4 druggable region, and therefore the possible DPP-4 inhibition mechanism. These results suggest that prepared garlic extract contains phytochemicals that inhibit DPP-4 and have antioxidant activity. Also, the prepared extract induces skeletal muscle cell proliferation that demonstrates the antidiabetic effect and its possible mechanism of action.

Background: Immune checkpoint blockade (ICB) induces durable response in approximately 20% of patients with advanced bladder urothelial cancer (aUC). Over 50% of aUCs harbor genomic alterations along the phosphoinositide 3-kinase (PI3K) pathway. The goal of this project was to determine the synergistic effects and mechanisms of action of PI3K inhibition and ICB combination in aUC. Methods: Alterations affecting the PI3K pathway were examined in The Cancer Genome Atlas (TCGA) and the Cancer Dependency Map databases. Human and mouse cells with Pten deletion were used for in vitro studies. C57BL/6 mice carrying syngeneic tumors were used to determine in vivo activity, mechanisms of action and secondary resistance of pan-PI3K inhibition, ICB and combination. Results: Alterations along the PI3K pathway occurred in 57% of aUCs in TCGA. CRISPR (clustered regularly interspaced short palindromic repeats) knockout of PIK3CA induced pronounced inhibition of cell proliferation (p=0.0046). PI3K inhibition suppressed cancer cell growth, migration and colony formation in vitro. Pan-PI3K inhibition, antiprogrammed death 1 (aPD1) therapy and combination improved the overall survival (OS) of syngeneic mice with PTEN-deleted tumors from 27 days of the control to 48, 37, and 65 days, respectively. In mice with tumors not containing a PI3K pathway alteration, OS was prolonged by the combination but not single treatments. Pan-PI3K inhibition significantly upregulated CD80, CD86, MHC-I, and MHC-II in dendritic cells, and downregulated the transforming growth factor beta pathway with a false discovery rate-adjusted q value of 0.001. Interferon alpha response was significantly upregulated with aPD1 therapy (q value: <0.001) and combination (q value: 0.027). Compared with the control, combination treatment increased CD8⁺ T-cell infiltration (p=0.005), decreased T_reg-cell infiltration (p=0.036), and upregulated the expression of multiple immunostimulatory cytokines and granzyme B (p<0.01). Secondary resistance was associated with upregulation of the mammalian target of rapamycin (mTOR) pathway and multiple Sprr family genes. Conclusions: The combination Pan-PI3K inhibition and ICB has significant antitumor effects in aUC with or without activated PI3K pathway and warrants further clinical investigation. This combination creates an immunostimulatory tumor milieu. Secondary resistance is associated with upregulation of the mTOR pathway and Sprr family genes.

Dipeptidyl peptidase-4 (DPP-4) is a well-known therapeutic drug target proven to reduce blood glucose levels in diabetes mellitus, and clinically, DPP-4 inhibitors are used in combination with other anti-diabetic agents. However, side effects and skeletal muscle health are not considered in the treatment for diabetic patients. Recently, natural compounds have been proven to inhibit DPP-4 with fewer side effects. In this work, initially, molecular docking simulations revealed that a natural compound, Galangin, possess a binding energy of −24 KJ/mol and interaction residues SER 630 and TYR 547, that are responsible for potent DPP-4 inhibition. In vitro studies showed that galangin not only inhibits DPP-4 in a concentration-dependent manner but also regulates glucose levels, enabling the proliferation of rat L6 skeletal muscle cells. The combination of galangin with insulin benefits regulation of glucose levels significantly in comparison to galangin alone (p < 0.05). These findings suggest the beneficial effect of the use of galangin, both alone or in combination with insulin, to reduce glucose levels and improve skeletal muscle health in diabetes mellitus.

Purpose: Immune checkpoint inhibitors (ICI) in general have shown poor efficacy in bladder cancer. The purpose of this project was to determine whether photodynamic therapy (PDT) with bladder cancer–specific porphyrin-based PLZ4-nanoparticles (PNP) potentiated ICI. Experimental Design: SV40 T/Ras double-transgenic mice bearing spontaneous bladder cancer and C57BL/6 mice carrying syngeneic bladder cancer models were used to determine the efficacy and conduct molecular correlative studies. Results: PDT with PNP generated reactive oxygen species, and induced protein carbonylation and dendritic cell maturation. In SV40 T/Ras double-transgenic mice carrying spontaneous bladder cancer, the median survival was 33.7 days in the control, compared with 44.8 (P = 0.0123), 52.6 (P = 0.0054), and over 75 (P = 0.0001) days in the anti-programmed cell death-1 antibody (anti-PD-1), PNP PDT, and combination groups, respectively. At Day 75 when all mice in other groups died, only 1 in 7 mice in the combination group died. For the direct anti-tumor activity, compared with the control, the anti-PD-1, PNP PDT, and combination groups induced a 40.25% (P = 0.0003), 80.72% (P < 0.0001), and 93.03% (P < 0.0001) tumor reduction, respectively. For the abscopal anticancer immunity, the anti-PD-1, PNP PDT, and combination groups induced tumor reduction of 45.73% (P = 0.0001), 54.92% (P < 0.0001), and 75.96% (P < 0.0001), respectively. The combination treatment also diminished spontaneous and induced lung metastasis. Potential of immunotherapy by PNP PDT is multifactorial. Conclusions: In addition to its potential for photodynamic diagnosis and therapy, PNP PDT can synergize immunotherapy in treating locally advanced and metastatic bladder cancer. Clinical trials are warranted to determine the efficacy and toxicity of this combination.