Evidence that cervical cancer cells cultured as tumorspheres maintain high CD73 expression and increase their protumor characteristics through TGF-β production

Interaction of Purine and its Derivatives with A1, A2-Adenosine Receptors and Vascular Endothelial Growth Factor Receptor-1 (Vegf-R1) as a Therapeutic Alternative to Treat Cancer

BACKGROUND

There are several studies that indicate that cancer development may be conditioned by the activation of some biological systems that involve the interaction of different biomolecules, such as adenosine and vascular endothelial growth factor. These biomolecules have been targeted of some drugs for treat of cancer; however, there is little information on the interaction of purine derivatives with adenosine and vascular endothelial growth factor receptor (VEGF-R1).

OBJECTIVE

The aim of this research was to determine the possible interaction of purine (1: ) and their derivatives (2-31: ) with A1, A2-adenosine receptors, and VEGF-R1.

METHODS

Theoretical interaction of purine and their derivatives with A1, A2-adenosine receptors and VEGF-R1 was carried out using the 5uen, 5mzj and 3hng proteins as theoretical tools. Besides, adenosine, cgs-15943, rolofylline, cvt-124, wrc-0571, luf-5834, cvt-6883, AZD-4635, cabozantinib, pazopanib, regorafenib, and sorafenib drugs were used as controls.

RESULTS

The results showed differences in the number of aminoacid residues involved in the interaction of purine and their derivatives with 5uen, 5mzj and 3hng proteins compared with the controls. Besides, the inhibition constants (Ki) values for purine and their derivatives 5: , 9: , 10: , 14: , 15: , 16: , and 20: were lower compared with the controls CONCLUSIONS: Theoretical data suggest that purine and their derivatives 5: , 9: , 10: , 14: , 15: , 16: , and 20: could produce changes in cancer cell growth through inhibition of A1, A2-adenosine receptors and VEGFR-1 inhibition. These data indicate that these purine derivatives could be a therapeutic alternative to treat some types of cancer.

ENTPD1 (CD39) and NT5E (CD73) expression in human medulloblastoma: an in silico analysis

Medulloblastoma is the most common malignant tumor in the pediatric population. Its classification has incorporated key molecular variations alongside histological characterization. CD39 (also known as ENTPD1) and CD73 (also known as NT5E), enzymes of the purinergic signaling pathway, act in synergy to generate extracellular adenosine, creating an immunosuppressive tumor microenvironment. Our study examined the expression of mRNA of these genes in previously described transcriptome data sets of medulloblastoma patient samples from the Cavalli Cohort (n = 763). Survival distribution was estimated according to the Kaplan-Meier method using a median cut-off and log-rank statistics (p ≤ 0.05). In non-WNT and non-SHH medulloblastoma Group 4 (n = 264), the high expression of ENTPD1 and NT5E was significantly related to a lower overall survival (p = 2.7e-04; p = 2.6e-03). In the SHH-activated group (n = 172), the high expression of ENTPD1 was significantly related to lower overall survival (p = 7.8e-03), while the high expression of NT5E was significantly related to greater overall survival (p = 0.017). In the WNT group (n = 63), the expressions of ENTPD1 and NT5E were not significantly correlated with overall survival (p = 0.212; p = 0.101). In non-WNT and non-SHH medulloblastoma Group 3 (n = 113), the high expression of ENTPD1 was significantly related to greater survival (p = 0.034), while expression of NT5E was not significantly related to survival of patients (p = 0.124). This in silico analysis indicates that ENTPD1 (CD39) and NT5E (CD73) can be seen as potential prognostic markers and therapeutic targets for primary medulloblastomas in non-WNT and non-SHH Group 4.

Integrating bulk-RNA sequencing and single-cell sequencing analyses to characterize adenosine-enriched tumor microenvironment landscape and develop an adenosine-related prognostic signature predicting immunotherapy in lung adenocarcinoma

The adenosine-signaling axis has been recognized as an important immunomodulatory pathway in tumor immunity. However, the biological role of the adenosine-signaling axis in the remodeling of the tumor microenvironment (TME) in lung adenocarcinoma (LUAD) remains unclear. Here, we quantified adenosine signaling (ado_sig) in LUAD samples using the GSVA method and assessed the prognostic value of adenosine in LUAD. Afterward, we explored the heterogeneity of the tumor-immune microenvironment at different adenosine levels. In addition, we analyzed the potential biological pathways engaged by adenosine. Next, we established single-cell transcriptional profiles of LUAD and analyzed cellular composition and cell-cell communication analysis under different adenosine microenvironments. Moreover, we established adenosine-related prognostic signatures (ARS) based on comprehensive bioinformatics analysis and evaluated the efficacy of ARS in predicting immunotherapy. The results demonstrated that adenosine signaling adversely impacted the survival of immune-enriched LUAD. The high-adenosine microenvironment exhibited elevated pro-tumor-immune infiltration, including M2 macrophages and displayed notably increased epithelial-mesenchymal transition (EMT) transformation. Furthermore, adenosine signaling displayed significant associations with the expression patterns and prognostic value of immunomodulators within the TME. Single-cell sequencing data revealed increased fibroblast occupancy and a prominent activation of the SPP1 signaling pathway in the high adenosine-signaling microenvironment. The ARS exhibited promising effectiveness in prognostication and predicting immunotherapy response in LUAD. In summary, overexpression of adenosine can cause a worsened prognosis in the LUAD with abundant immune infiltration. Moreover, increased adenosine levels are associated with pro-tumor-immune infiltration, active EMT transformation, pro-tumor angiogenesis, and other factors promoting cancer progression, which collectively contribute to the formation of an immunosuppressive microenvironment. Importantly, the ARS developed in this study demonstrate high efficacy in evaluating the response to immunotherapy.

Soluble galectin-3 as a microenvironment-relevant immunoregulator with prognostic and predictive value in lung adenocarcinoma

Despite the success of therapies in lung cancer, more studies of new biomarkers for patient selection are urgently needed. The present study aims to analyze the role of galectin-3 (GAL-3) in the lung tumor microenvironment (TME) using tumorspheres as a model and explore its potential role as a predictive and prognostic biomarker in non-small cell lung cancer patients. For in vitro studies, lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC) primary cultures from early-stage patients and commercial cell lines were cultured, using tumorsphere-forming assays and adherent conditions for the control counterparts. We analyzed the pattern of secretion and expression of GAL-3 using reverse transcription-quantitative real-time PCR (RTqPCR), immunoblot, immunofluorescence, flow cytometry, and immunoassay analysis. Our results using three-dimensional (3D) models of lung tumor cells revealed that soluble GAL-3 (sGAL-3) is highly expressed and secreted. To more accurately mimic the TME, a co-culture of tumorspheres and fibroblasts was used, revealing that GAL-3 could be important as an immunomodulatory molecule expressed and secreted in the TME, modulating immunosuppression through regulatory T cells (TREGS ). In the translational phase, we confirmed that patients with high expression levels of GAL-3 had more TREGS , which suggests that tumors may be recruiting this population through GAL-3. Next, we evaluated levels of sGAL-3 before surgery in LUAD and LUSC patients, hypothesizing that sGAL-3 could be used as an independent prognostic biomarker for overall survival and relapse-free survival in early-stage LUAD patients. Additionally, levels of sGAL-3 at pretreatment and first response assessment from plasma to predict clinical outcomes in advanced LUAD and LUSC patients treated with first-line pembrolizumab were evaluated, further supporting that sGAL-3 has a high efficiency in predicting durable clinical response to pembrolizumab with an area under curve of 0.801 (P = 0.011). Moreover, high levels might predict decreased progression-free survival and OS to anti-PD-1 therapy, with sGAL-3 being a prognosis-independent biomarker for advanced LUAD.

Targeting Cervical Cancer Stem Cells by Phytochemicals

Cervical cancer (CaCx) poses a significant global health challenge, ranking as the fourth most common cancer among women worldwide. Despite the emergence of advanced treatment strategies, recurrence remains a bottleneck in favorable treatment outcomes and contributes to poor prognosis. The chemo- or radio-therapy resistance coupled with frequent relapse of more aggressive tumors are some key components that contribute to CaCx-related mortality. The onset of therapy resistance and relapse are attributed to a small subset of, slow-proliferating Cancer Stem Cells (CSC). These CSCs possess the properties of tumorigenesis, self-renewal, and multi-lineage differentiation potential. Because of slow cycling, these cells maintain themselves in a semi-quiescent stage and protect themselves from different anti-proliferative anti-cancer drugs. Keeping in view recent advances in their phenotypic and functional characterization, the feasibility of targeting CSC and associated stem cell signaling bears a strong translational value. The presence of CSC has been reported in CaCx (CCSC) which remains a forefront area of research. However, we have yet to identify clinically useful leads that can target CCSC. There is compelling evidence that phytochemicals, because of their advantages over synthetic anticancer drugs, could emerge as potential therapeutic leads to target these CCSCs. The present article examined the potential of phytochemicals with reported anti-CSC properties and evaluated their future in preclinical and clinical applications against CaCx.

Purinergic system in cancer stem cells

Accumulating evidence supports the idea that cancer stem cells (CSCs) are those with the capacity to initiate tumors, generate phenotypical diversity, sustain growth, confer drug resistance, and orchestrate the spread of tumor cells. It is still controversial whether CSCs originate from normal stem cells residing in the tissue or cancer cells from the tumor bulk that have dedifferentiated to acquire stem-like characteristics. Although CSCs have been pointed out as key drivers in cancer, knowledge regarding their physiology is still blurry; thus, research focusing on CSCs is essential to designing novel and more effective therapeutics. The purinergic system has emerged as an important autocrine-paracrine messenger system with a prominent role at multiple levels of the tumor microenvironment, where it regulates cellular aspects of the tumors themselves and the stromal and immune systems. Recent findings have shown that purinergic signaling also participates in regulating the CSC phenotype. Here, we discuss updated information regarding CSCs in the purinergic system and present evidence supporting the idea that elements of the purinergic system expressed by this subpopulation of the tumor represent attractive pharmacological targets for proposing innovative anti-cancer therapies.

Inhibition of CD73 expression or A2AR blockade reduces MRP1 expression and increases the sensitivity of cervical cancer cells to cisplatin

Recently, a link between the biological activity of CD73 in solid tumors and multidrug resistance protein (MRP) has been proposed. Cisplatin (CP) is the most widely used anticancer agent to treat advanced and recurrent cervical cancer (CC). However, multidrug resistance protein-1 (MRP1) is overexpressed in approximately 85% of these tumors and has been strongly associated with cisplatin resistance (CPR). In this study, we examine the involvement of CD73 and the interaction of adenosine (ADO) with its receptors (ARs) in MRP1 expression in CC cells. We found that ADO positively modulates MRP1 expression in CC cells in a dose-dependent manner. The inhibition of CD73 expression with a CD73-targeted siRNA and A2AR blockade with the selective antagonist ZM241385 significantly decreased MRP1 expression and the extrusive capacity of CC cells, making them significantly more sensitive to CP treatment than cancer cells treated with MK-751, a specific MRP1 inhibitor. These results suggest CD73 inhibition or blocking ADO signaling through A2AR could be strategies to reverse CPR in patients with advanced or recurrent CC, which is characterized by very low response rates to CP (10%-20%).