HPV-16 Infection Is Associated with a High Content of CD39 and CD73 Ectonucleotidases in Cervical Samples from Patients with CIN-1

High levels of soluble CD73 unveil resistance to BRAF inhibitors in melanoma cells

Melanoma cells express high levels of CD73 that produce extracellular immunosuppressive adenosine. Changes in the CD73 expression occur in response to tumor environmental factors, contributing to tumor phenotype plasticity and therapeutic resistance. Previously, we have observed that CD73 expression can be up-regulated on the surface of melanoma cells in response to nutritional stress. Here, we explore the mechanism by which melanoma cells release soluble CD73 under low nutrient availability and whether this might be affected by agents targeting the proto-oncogene B-Raf (BRAF). We found that starved melanoma cells can release high levels of CD73, able to convert AMP into adenosine, and this activity is abrogated by selective CD73 inhibitors, APCP or PSB-12489. The release of CD73 from melanoma cells is mediated by the matrix metalloproteinase MMP-9. Indeed, MMP-9 inhibitors significantly reduce the levels of CD73 released from the cells, while its surface levels increase. Of relevance, melanoma cells, harboring an activating BRAF mutation, upon treatment with dabrafenib or vemurafenib, show a strong reduction of CD73 cell expression and reduced levels of CD73 released into the extracellular space. Conversely, melanoma cells resistant to dabrafenib show high expression of membrane-bound CD73 and soluble CD73 released into the culture medium. In summary, our data indicate that CD73 is released from melanoma cells. The expression of CD73 is associated with response to BRAF inhibitors. Melanoma cells developing resistance to dabrafenib show increased expression of CD73, including soluble CD73 released from cells, suggesting that CD73 is involved in acquiring resistance to treatment.

Expression of HPV-16 E6 and E7 oncoproteins alters Chlamydia trachomatis developmental cycle and induces increased levels of immune regulatory molecules

Introduction

Infection with Human Papillomavirus (HPV) is a recognized risk factor for Chlamydia trachomatis (CT) infection and vice versa. Coinfection of HPV and CT in women is a very common and usually asymptomatic finding that has been linked to increased risk of cervical cancer. It has been demonstrated that CT facilitates the entry of multiple high risk HPV genotypes, leading to damage of the mucosal barrier and interfering with immune responses and viral clearance, which ultimately favours viral persistence and malignant transformation. Although the facilitating effects elicited by CT infection on viral persistence have been reported, little is known about the consequences of HPV infection on CT development.

Methods

Herein, we took advantage of a genetically modified human cervical cell line co-expressing HPV-16 major oncogenic proteins E6 and E7, as an experimental model allowing to investigate the possible effects that HPV infection would have on CT development.

Results and discussion

Our results show that CT infection of HPV-16 E6E7 expressing cells induced an upregulation of the expression of E6E7 oncoproteins and host cell inhibitory molecules PD-L1, HVEM and CD160. Additionally, smaller chlamydial inclusions and reduced infectious progeny generation was observed in E6E7 cells. Ultrastructural analysis showed that expression of E6 and E7 did not alter total bacterial counts within inclusions but resulted in increased numbers of reticulate bodies (RB) and decreased production of infectious elementary bodies (EB). Our results indicate that during CT and HPV coinfection, E6 and E7 oncoproteins impair RB to EB transition and infectious progeny generation. On the other hand, higher expression of immune inhibitory molecules and HPV-16 E6E7 are cooperatively enhanced in CT-infected cells, which would favour both oncogenesis and immunosuppression. Our findings pose important implications for clinical management of patients with HPV and CT coinfection, suggesting that screening for the mutual infection could represent an opportunity to intervene and prevent severe reproductive health outcomes, such as cervical cancer and infertility.

The crossroads of adenosinergic pathway and epithelial-mesenchymal plasticity in cancer

Epithelial-mesenchymal transition (EMT) is a key mechanism related to tumor progression, invasion, metastasis, resistance to therapy and poor prognosis in several types of cancer. However, targeting EMT or partial-EMT, as well as the molecules involved in this process, has remained a challenge. Recently, the CD73 enzyme, which hydrolyzes AMP to produce adenosine (ADO), has been linked to the EMT process. This relationship is not only due to the production of the immunosuppressant ADO but also to its role as a receptor for extracellular matrix proteins, being involved in cell adhesion and migration. This article reviews the crosstalk between the adenosinergic pathway and the EMT program and the impact of this interrelation on cancer development and progression. An in silico analysis of RNAseq datasets showed that several tumor types have a significant correlation between an EMT score and NT5E (CD73) and ENTPD1 (CD39) expressions, with the strongest correlations in prostate adenocarcinoma. Furthermore, it is evident that the cooperation between EMT and adenosinergic pathway in tumor progression is context and tumor-dependent. The increased knowledge about this topic will help broaden the view to explore new treatments and therapies for different types of cancer.

Serum CD73 is a prognostic factor in patients with metastatic melanoma and is associated with response to anti-PD-1 therapy

Background

Inhibitors of immune checkpoint programmed cell death protein 1 (PD-1) receptor on T cells have shown remarkable clinical outcomes in metastatic melanoma. However, most patients are resistant to therapy. Production of extracellular adenosine, via CD73-mediated catabolism of AMP, contributes to suppress T-cell-mediated responses against cancer. In this study, we analyzed the expression and activity of soluble CD73 in sera of patients with melanoma undergoing anti-PD-1± cytotoxic T-lymphocyte-associated antigen 4 therapy.

Methods

Soluble CD73 expression and activity were retrospectively analyzed in serum of a total of 546 patients with melanoma from different centers before starting treatment (baseline) with anti-PD-1 agents, nivolumab or pembrolizumab, and compared with those of 96 healthy subjects. The CD73 activity was correlated with therapy response and survival of patients.

Results

Patients with melanoma show significantly higher CD73 activity and expression than those observed in healthy donors (p<0.0001). Elevated pretreatment levels of CD73 activity were associated with non-response to therapy with nivolumab or pembrolizumab. During treatment, levels of soluble CD73 activity remain unchanged from baseline and still stratify clinical responders from non-responders. High levels of serum CD73 enzymatic activity associate with reduced overall survival (OS; HR=1.36, 95% CI 1.03 to 1.78; p=0.03) as well as progression-free survival (PFS; HR=1.42, 95% CI 1.13 to 1.79, p=0.003). Further, the multivariate Cox regression analysis indicates that serum CD73 activity is an independent prognostic factor besides serum lactate dehydrogenase levels and the presence of brain metastases for both OS (p=0.009) and PFS (p=0.001).

Conclusion

Our data indicate the relevance of serum CD73 in patients with advanced melanoma receiving anti-PD-1 therapy and support further investigation on targeting CD73 in combination with anti-PD-1 antibodies.

TIM-3 as a potential exhaustion marker in CD4+ T cells of COVID-19 patients

Background

COVID‐19 causes a range of clinical symptoms from mild to critical and can be life‐threatening. Up to now, it has led to many deaths. We aimed to evaluate exhausted markers on CD4⁺ T cells of COVID‐19 patients.

Methods

In this study, we evaluated 44 patients with confirmed COVID‐19 disease and 16 healthy individuals. Patients were divided into moderate/severe and critical groups. Peripheral blood mononuclear cells (PBMCs) were isolated and stained by anti‐human CD39, PD‐1, TIM‐3, and anti‐human CD4. The percentage of each CD4⁺ subpopulation was calculated by flow cytometry. Furthermore, we collected clinical information and laboratory data of both control and patient groups.

Results

We detected overexpression of TIM‐3 on CD4⁺ T cells in both critical and moderate/severe patients than in healthy individuals (HIs; p < .01 and p < .0001, respectively). CD4⁺ TIM‐3⁺ CD39⁺ lymphocytes were significantly higher in the critical patients than in HI (p < .05). Both Patient groups showed lymphopenia in comparison with HI, but CD4⁺ lymphocytes did not show any significant difference between study subjects. The increased amount of C‐reactive protein, erythrocyte sedimentation rate, creatinine, blood urea nitrogen, and neutrophil count was observed in patients compared to HI.

Conclusion

T cell exhaustion occurs during COVID‐19 disease and TIM‐3 is the most important exhausted marker on CD4⁺ T cells.

ATP and cancer immunosurveillance

While intracellular adenosine triphosphate (ATP) occupies a key position in the bioenergetic metabolism of all the cellular compartments that form the tumor microenvironment (TME), extracellular ATP operates as a potent signal transducer. The net effects of purinergic signaling on the biology of the TME depend not only on the specific receptors and cell types involved, but also on the activation status of cis- and trans-regulatory circuitries. As an additional layer of complexity, extracellular ATP is rapidly catabolized by ectonucleotidases, culminating in the accumulation of metabolites that mediate distinct biological effects. Here, we discuss the molecular and cellular mechanisms through which ATP and its degradation products influence cancer immunosurveillance, with a focus on therapeutically targetable circuitries.

Detection of CD39 and a Highly Glycosylated Isoform of Soluble CD73 in the Plasma of Patients with Cervical Cancer: Correlation with Disease Progression

Persistent infection with high-risk human papillomavirus (HR-HPV) is the main factor in the development of cervical cancer (CC). The presence of immunosuppressive factors plays an important role in the development of this type of cancer. To determine whether CD39 and CD73, which participate in the production of immunosuppressive adenosine (Ado), are involved in the progression of CC, we compared the concentrations and hydrolytic activity of these ectonucleotidases in platelet-free plasma (PFP) samples between patients with low-grade squamous intraepithelial lesions (LSILs) (n = 18), high-grade squamous intraepithelial lesions (HSILs) (n = 12), and CC (n = 19) and normal donors (NDs) (n = 15). The concentrations of CD39 and CD73 in PFP increased with disease progression (r = 0.5929, p < 0.001). The PFP of patients with HSILs or CC showed the highest concentrations of CD39 (2.3 and 2.2 times that of the NDs, respectively) and CD73 (1.7 and 2.68 times that of the NDs, respectively), which were associated with a high capacity to generate Ado from the hydrolysis of adenosine diphosphate (ADP) and adenosine monophosphate (AMP). The addition of POM-1 and APCP, specific inhibitors of CD39 and CD73, respectively, inhibited the ADPase and AMPase activity of PFP by more than 90%. A high level of the 90 kD isoform of CD73 was detected in the PFP of patients with HSILs or CC. Digestion with endoglycosidase H and N-glycanase generated CD73 with weights of approximately 90 kD, 85 kD, 80 kD, and 70 kD. In addition, the levels of transforming grow factor-β (TGF-β) in the PFPs of patients with LSIL, HSIL and CC positively correlated with those of CD39 (r = 0.4432, p < 0.001) and CD73 (r = 0.5786, p < 0.001). These results suggest that persistent infection by HR-HPV and the concomitant production of TGF-β promote the expression of CD39 and CD73 to favor CC progression through Ado generation.

Clinical significance of peripheral blood and tumor tissue lymphocyte subsets in cervical cancer patients

Background

Alterations in peripheral blood lymphocytes in cervical cancer have been reported, although conflicting views exist. The present study investigated the distributions of lymphocyte subsets in tumor tissue and peripheral blood samples from cervical cancer patients and precancerous lesion patients, and evaluated the correlations of lymphocyte subsets with clinicopathological and prognostic variables.

Methods

A total of 44 patients with stage IB1-IIA2 cervical cancer and 13 precancerous lesion patients were included. Lymphocytes were collected from the tumor tissue and the peripheral blood, and isolated by Lymphoprep density gradient centrifugation. The percentages of lymphocyte subsets were quantified by flow cytometry analysis, and the differences between lymphocyte subsets in the tumor tissue and peripheral blood were compared by SPSS. In addition, the relationships between lymphocyte subsets and clinicopathological and prognostic variables were analyzed.

Results

Our results revealed that the amount of total T lymphocytes, CD8+ T cells, granulocytes, pDCs, CD16+ monocytes and CD56^high NK cells were significantly higher in the tumor tissue than in the peripheral blood in the cervical cancer patients, while those of CD4+ T cells, CD4+/CD8+ cell ratio, rdT cells, BDCA1+ mDCs, total monocytes, CD14+ monocytes, NK cells and CD56^low NK cells exhibited the opposite trend (p < 0.05). The levels of total pDCs and BDCA1+ mDCs in the peripheral blood were significantly lower in the cervical cancer patients than in the precancerous lesion patients, while the proportion of CD16+ monocytes was elevated (p < 0.05). In addition, some lymphocyte subsets, especially CD4+ cells and CD8+ cells, and the CD4+/CD8+ cell ratio were closely associated with clinicopathological and prognostic parameters.

Conclusions

These results suggested that distinct alterations in infiltrating lymphocyte subsets occurred in the tumor and were associated with clinicopathological and prognostic parameters. Systemic impairment of the immune system may occur in the antitumor response of cervical cancer patients.

Purinergic signaling and tumor microenvironment in cervical Cancer

Cervical cancer is the fourth most common type of cancer incidence in the world female population, and it has become a public health problem worldwide. Several factors are involved in this type of cancer, including intrinsic factors related to the inflammatory process, such as extracellular nucleotides and adenosine-components of the purinergic system. The present review focuses on the role of the purinergic system in cervical cancer, especially regarding the interaction of extracellular nucleotides with their respective receptors expressed in the tumor microenvironment of cervical cancer and their role in the host immune response. The high concentrations of extracellular nucleotides in the tumor microenvironment of cervical cancer interfere in the regulation, proliferation, differentiation, and apoptosis of cancer cells of the uterine cervix through different P1 and P2 receptor subtypes. Such diverse cellular processes that are mediated by adenosine triphosphate and adenosine across the tumor microenvironment and that also have effects on host immune defense will be reviewed here in detail.

ADH7, miR-3065 and LINC01133 are associated with cervical cancer progression in different age groups

The aim of the present study was to identify potential therapeutic targets that serve crucial roles in the progression of cervical cancer. Clinical data, RNA sequencing (RNAseq)-counts and micro (mi)RNA data regarding cervical squamous cell carcinoma were retrieved from The Cancer Genome Atlas, and analyses were performed using the University of California Santa Cruz database. RNAseq and miRNA data were stratified into 3 groups (according to the patients' age), and genes were re-annotated and preprocessed prior to Mfuzz time clustering analysis. Subsequently, enrichment analyses were performed in order to identify differentially expressed mRNAs (DEmRNAs) and a protein-protein interaction analysis network was constructed. miRNA-gene, miRNA-lncRNA, and long non-coding (lnc)RNA-mRNA pairs were collected and the lncRNA-miRNA-mRNA competing endogenous (ce)RNA network was established. Further enrichment analyses were performed in order to identify crucial mRNAs in the ceRNA network. Finally, survival and drug association analyses were implemented. A total of 269 DEmRNAs [including alcohol dehydrogenase 7 (ADH7), vestigial-like family member 3 (VGLL3) and cytochrome P450, family 26, subfamily B, polypeptide 1 (CYP26B1)], 274 DElncRNAs (including LINC01133) and 16 DEmiRNAs (including miR-3065 and miR-330) were identified. There were 102 lncRNAs, 15 miRNAs, 15 mRNAs and 522 interaction pairs in the ceRNA network. In particular, ADH7 was regulated by miR-3065, and miR-3065 interacted with LINC01133 in the ceRNA network. Furthermore, ADH7 and CYP26B1 were enriched in the retinoic acid metabolic process and the retinol metabolism pathway. ADH7 and VGLL3 were significantly associated with the cervical cancer survival rate. ADH7, VGLL3, CYP26B1, miR-3065, miR-330, miR-499a and LINC01133 play pivotal roles in the progression of cervical cancer in different age groups.