Tumor microenvironment of human breast cancer, and feline mammary carcinoma as a potential study model

The role of microRNAs in the gastric cancer tumor microenvironment

BACKGROUND

Gastric cancer (GC) is one of the deadliest malignant tumors with unknown pathogenesis. Due to its treatment resistance, high recurrence rate, and lack of reliable early detection techniques, a majority of patients have a poor prognosis. Therefore, identifying new tumor biomarkers and therapeutic targets is essential. This review aims to provide fresh insights into enhancing the prognosis of patients with GC by summarizing the processes through which microRNAs (miRNAs) regulate the tumor microenvironment (TME) and highlighting their critical role in the TME.

MAIN TEXT

A comprehensive literature review was conducted by focusing on the interactions among tumor cells, extracellular matrix, blood vessels, cancer-associated fibroblasts, and immune cells within the GC TME. The role of noncoding RNAs, known as miRNAs, in modulating the TME through various signaling pathways, cytokines, growth factors, and exosomes was specifically examined. Tumor formation, metastasis, and therapy in GC are significantly influenced by interactions within the TME. miRNAs regulate tumor progression by modulating these interactions through multiple signaling pathways, cytokines, growth factors, and exosomes. Dysregulation of miRNAs affects critical cellular processes such as cell proliferation, differentiation, angiogenesis, metastasis, and treatment resistance, contributing to the pathogenesis of GC.

CONCLUSIONS

miRNAs play a crucial role in the regulation of the GC TME, influencing tumor progression and patient prognosis. By understanding the mechanisms through which miRNAs control the TME, potential biomarkers and therapeutic targets can be identified to improve the prognosis of patients with GC.

Advances in targeting cancer-associated fibroblasts through single-cell spatial transcriptomic sequencing

Cancer-associated fibroblasts (CAFs) are the major components of the tumor microenvironment and are related to tumor proliferation, metastasis, relapse, and drug resistance. With the development of sequencing technologies, single-cell RNA sequencing has become a popular method for identifying CAFs in the tumor microenvironment. Whereas the drawbacks of CAFs, such as the lack of a spatial landscape, still exist, recent research has utilized spatial transcriptomics combined with single-cell RNA sequencing to address this issue. These multiomics analyses can resolve the single-cell resolution problem in spatial transcriptomics. In this review, we summarized the recent literature regarding the targeting of CAFs to address drug resistance, angiogenesis, metabolic reprogramming and metastasis in tumor tissue.

Analysis of serum peptidome profiles of non-metastatic and metastatic feline mammary carcinoma using liquid chromatography-tandem mass spectrometry

BACKGROUND

Feline mammary carcinoma (FMC) is a common aggressive and highly metastatic cancer affecting female cats. Early detection is essential for preventing local and distant metastasis, thereby improving overall survival rates. While acquiring molecular data before surgery offers significant potential benefits, the current protein biomarkers for monitoring disease progression in non-metastatic FMC (NmFMC) and metastatic FMC (mFMC) are limited. The objective of this study was to investigate the serum peptidome profiles of NmFMC and mFMC using liquid chromatography-tandem mass spectrometry. A cross-sectional study was conducted to compare serum peptidome profiles in 13 NmFMC, 23 mFMC and 18 healthy cats. The liquid chromatography-tandem mass spectrometry analysis was performed on non-trypsinized samples.

RESULTS

Out of a total of 8284 expressed proteins observed, several proteins were found to be associated with human breast cancer. In NmFMC, distinctive protein expressions encompassed double-stranded RNA-binding protein Staufen homolog 2 (STAU2), associated with cell proliferation, along with bromodomain adjacent to zinc finger domain 2A (BAZ2A) and gamma-aminobutyric acid type A receptor subunit epsilon (GABRE), identified as potential treatment targets. Paradoxically, positive prognostic markers emerged, such as complement C1q like 3 (C1QL3) and erythrocyte membrane protein band 4.1 (EPB41 or 4.1R). Within the mFMC group, overexpressed proteins associated with poor prognosis were exhibited, including B-cell lymphoma 6 transcription repressor (BCL6), thioredoxin reductase 3 (TXNRD3) and ceruloplasmin (CP). Meanwhile, the presence of POU class 5 homeobox (POU5F1 or OCT4) and laminin subunit alpha 1 (LAMA1), reported as metastatic biomarkers, was noted.

CONCLUSION

The presence of both pro- and anti-proliferative proteins was observed, potentially indicating a distinctive characteristic of NmFMC. Conversely, proteins associated with poor prognosis and metastasis were noted in the mFMC group.

Harnessing exosomes as a platform for drug delivery in breast cancer: A systematic review for in vivo and in vitro studies

Breast cancer remains a significant global health concern, emphasizing the critical need for effective treatment strategies, especially targeted therapies. This systematic review summarizes the findings from in vitro and in vivo studies regarding the therapeutic potential of exosomes as drug delivery platforms in the field of breast cancer treatment. A comprehensive search was conducted across bibliographic datasets, including Web of Science, PubMed, and Scopus, using relevant queries from several related published articles and the Medical Subject Headings Database. Then, all morphological, biomechanical, histopathological, and cellular-molecular outcomes were systematically collected. A total of 30 studies were identified based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. These studies underwent assessment using the Systematic Review Centre for Laboratory Animal Experimentation risk of bias assessment tool. The results indicate that exosomes exhibit promise as effective drug delivery platforms, capable of hindering cancer cell viability, proliferation, migration, and angiogenesis. However, a comprehensive assessment is challenging due to some studies deviating from guidelines and having incomplete methodology. Addressing these, future studies should detail methodologies, optimize dosing, and enhance exosome production. Standardization in reporting, consistent protocols, and exploration of alternative sources are crucial.

Distribution of Inflammatory Infiltrate in Feline Mammary Lesions: Relationship With Clinicopathological Features

Inflammation is a frequent finding in feline mammary neoplasms. Recent research suggests that the presence and location of tumour-associated immune cells might play a significant role in the clinical outcome of feline mammary carcinomas. The present study aimed to characterise the overall inflammatory infiltrates in healthy, hyperplastic/dysplastic, benign and malignant lesions of the feline mammary gland, and to evaluate its association with clinicopathological features. Perilesional and intralesional inflammatory foci were evaluated in 307 lesions from 185 queens, and categorised according to its distribution and intensity. The presence, location and density of tertiary lymphoid structures were also assessed. A control group included 24 queens without mammary changes. The presence of intralesional and perilesional inflammatory infiltrate was observed in a majority of the lesions (80.8% and 90.2%, respectively), but differed according to the type of mammary lesion, being more remarkable in malignant neoplasms. Only scarce individual cells were observed in 28.1% of the normal mammary glands. Data analysis revealed statistically significant associations (p < 0.05) between the presence of a more prominent intralesional and perilesional inflammatory reaction and several clinicopathological features associated with worse prognosis, including clinical stage, tumour size, mitotic count, lymphovascular invasion and lymph node metastasis. Furthermore, tertiary lymphoid structures were significantly more frequent in tumours with an infiltrative growth and lymph node metastasis. According to our results, the inflammatory reaction present in different types of feline mammary lesions is associated with the development of more aggressive tumours.

Single cell RNA-sequencing of feline peripheral immune cells with V(D)J repertoire and cross species analysis of T lymphocytes

Introduction

The domestic cat (Felis catus) is a valued companion animal and a model for virally induced cancers and immunodeficiencies. However, species-specific limitations such as a scarcity of immune cell markers constrain our ability to resolve immune cell subsets at sufficient detail. The goal of this study was to characterize circulating feline T cells and other leukocytes based on their transcriptomic landscape and T-cell receptor repertoire using single cell RNA-sequencing.

Methods

Peripheral blood from 4 healthy cats was enriched for T cells by flow cytometry cell sorting using a mouse anti-feline CD5 monoclonal antibody. Libraries for whole transcriptome, alpha/beta T cell receptor transcripts and gamma/delta T cell receptor transcripts were constructed using the 10x Genomics Chromium Next GEM Single Cell 5' reagent kit and the Chromium Single Cell V(D)J Enrichment Kit with custom reverse primers for the feline orthologs.

Results

Unsupervised clustering of whole transcriptome data revealed 7 major cell populations - T cells, neutrophils, monocytic cells, B cells, plasmacytoid dendritic cells, mast cells and platelets. Sub cluster analysis of T cells resolved naive (CD4+ and CD8+), CD4+ effector T cells, CD8+ cytotoxic T cells and gamma/delta T cells. Cross species analysis revealed a high conservation of T cell subsets along an effector gradient with equitable representation of veterinary species (horse, dog, pig) and humans with the cat. Our V(D)J repertoire analysis demonstrated a skewed T-cell receptor alpha gene usage and a restricted T-cell receptor gamma junctional length in CD8+ cytotoxic T cells compared to other alpha/beta T cell subsets. Among myeloid cells, we resolved three clusters of classical monocytes with polarization into pro- and anti-inflammatory phenotypes in addition to a cluster of conventional dendritic cells. Lastly, our neutrophil sub clustering revealed a larger mature neutrophil cluster and a smaller exhausted/activated cluster.

Discussion

Our study is the first to characterize subsets of circulating T cells utilizing an integrative approach of single cell RNA-sequencing, V(D)J repertoire analysis and cross species analysis. In addition, we characterize the transcriptome of several myeloid cell subsets and demonstrate immune cell relatedness across different species.

In vitro evaluation of the efficacy of photodynamic therapy using 5-ALA on homologous feline mammary tumors in 2D and 3D culture conditions and a mouse subcutaneous model with 3D cultured cells

BACKGROUND

Numerous studies have shown that photodynamic therapy (PDT) has a therapeutic effect on mammary tumor cells, with 5-aminolevulinic acid (5-ALA-HCL) being a commonly used photosensitizer for PDT. Feline mammary tumors (FMTs) are relatively common. However, the cytotoxic and antitumor effects of 5-ALA-PDT on FMTs have not been clarified. To this end, we evaluated the therapeutic effect of 5-ALA-PDT on FMTs through in vitro experiments using an FMT FKR cell line established for this study.

METHODS

We performed 5-ALA-PDT in 2D-cultured FKR-A (adherent cells) and 3D-cultured FKR-S (spheroid cells) cells and performed a series of studies to evaluate the cell viability and determine the protoporphyrin IX (PpIX) content in the cells as well as the expression levels of mRNAs associated with PpIX production and release. An in vivo study was performed to assess the effectiveness of 5-ALA-PDT.

RESULTS

There was a significant difference in the concentration of PpIX in FMT cells under different incubation culture modes (2D versus 3D culture). The concentration of PpIX in FMT cells was correlated with the differences in cell culture (2D and 3D) as well as the expression levels of genes such as PEPT1, PEPT2, FECH, and HO-1.

CONCLUSIONS

In the in vitro study, 5-ALA-PDT had a stronger inhibitory effect on 3D-cultured FKR-S cells, which resemble the internal environment of organisms more closely. We also observed a significant inhibitory effect of 5-ALA-PDT on FMT cells in vivo. To our knowledge, this is the first study on 5-ALA-PDT for FMTs under both 2D and 3D conditions.

Comparative pharmacokinetics of free doxorubicin and a liposomal formulation in cats following intravenous administration

Doxorubicin, a potent chemotherapeutic agent used extensively in cancer treatment, displays complex pharmacokinetic behavior, especially across various formulations. With a rising incidence of cancer cases in cats, understanding the drug's pharmacokinetics in feline subjects remains a critical yet unexplored area. Hence, this study investigated the pharmacokinetic profile of doxorubicin after slow intravenous administration of doxorubicin hydrochloride (DOX·HCl) or doxorubicin hydrochloride pegylated liposome (DOX·HCl-PLI) in twelve cats at a single dose of 20 mg/m2. Blood samples collected at pretreatment time (0 h) and over 192 h were analyzed using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS). The obtained pharmacokinetic parameters of doxorubicin revealed significant differences between the two formulations and were as follows: elimination half-life (T1/2λz) of 5.00 ± 3.20 h (DOX·HCl) and 17.62 ± 8.13 h (DOX·HCl-PLI), area under the concentration/time curve from 0 to last point (AUClast) of 0.67 ± 0.12 μg hr./mL (DOX·HCl) and 783.09 ± 267.29 μg hr./mL (DOX·HCl-PLI), and total body clearance (CL_obs) of 27098.58 ± 5205.19 mL/h/m2 (DOX·HCl) and 28.65 ± 11.09 mL/h/m2 (DOX·HCl-PLI). Additionally, differences were also detected in the apparent volume of distribution (Vz_obs) with 178.56 ± 71.89 L/m2 (DOX·HCl) and 0.64 ± 0.20 L/m2 (DOX·HCl-PLI), and the maximum plasma concentration (Cmax) with 2.25 ± 0.30 μg/mL (DOX·HCl) and 24.02 ± 5.45 μg/mL (DOX·HCl-PLI). Notably, low concentration of doxorubicinol, the metabolite of doxorubicin, was detected in plasma after administration of DOX·HCl, with even less present when DOX·HCl-PLI was administered. This investigation provides valuable insights into the distinct pharmacokinetic behaviors of DOX·HCl and DOX·HCl-PLI in cats, contributing essential groundwork for future studies and potential clinical applications in feline oncology.

Mammary carcinoma: Comparative oncology between small animals and humans-New therapeutic tools

The poor outcomes associated with mammary carcinomas (MCs) in dogs and cats in terms of locoregional recurrence, distant metastasis and survival, highlight the need for better management of mammary cancers in small animals. By contrast, the outcomes of women with breast cancer (BC) have dramatically improved during the last 10 years, notably thanks to new therapeutic strategies. The aim of this article was to imagine what could be the future of therapy for dogs and cats with MCs if it became inspired from current practices in human BC. This article focuses on the importance of taking into account cancer stage and cancer subtypes in therapeutic plans, on locoregional treatments (surgery, radiation therapy), new developments in endocrine therapy, chemotherapy, PARP inhibitors and immunotherapy. Ideally, multimodal treatment regimens would be chosen according to cancer stage and cancer subtypes, and according to predictive factors that are still to be defined.

Serum cytokine profiles in patients with pancreatic cancer and chronic pancreatitis

BACKGROUND

Chronic pancreatitis (CP) may cause tumor-like lesions, creating a challenge in distinguishing between CP and pancreatic ductal adenocarcinoma (PDAC) in a patient. Given that invasive surgery is a standard cancer treatment, we aimed to examine whether a noninvasive diagnostic tool utilizing serum cytokines could safely differentiate between PDAC and CP.

METHODS

A pre-operative serum panel comprising 48 inflammatory cytokines, CA19-9, and C-reactive protein (CRP) was analyzed, consisting of 231 patients, 186 with stage I-III PDAC and 45 with CP. We excluded PDAC patients who underwent neoadjuvant therapy and those CP patients with other active malignancies. The laboratory variables most associated with PDAC diagnosis were assessed using logistic regression and selected using the lasso method.

RESULTS

The cytokines CTACK, GRO-α, and β-NGF were selected alongside CA19-9 and CRP for our differential diagnostic model. The area under the curve (AUC) for our differential diagnostic model was 0.809 (95% confidence interval [CI] 0.738-0.880), compared with 0.791 (95% CI 0.728-0.854) for CA19-9 alone (not significant).

CONCLUSIONS

We found that inflammatory cytokines CTACK, GRO-α, and β-NGF alongside CA19-9 and CRP may help distinguish PDAC from CP.

Adipocyte-Derived Adipokines and Other Obesity-Associated Molecules in Feline Mammary Cancer

Obesity has been identified as a serious health concern in domestic cats. Feline mammary cancer (FMC) is also a concern, as it is highly prevalent and aggressive. Considering the identified connection between obesity and breast cancer, it is worthwhile to investigate the potential obesity-cancer relationship in FMC. This review investigated the association between adipokines and other obesity-associated molecules and FMC, with the aim of identifying gaps in the current literature for future research. Based on the reports to date, it was found that tissue concentrations of leptin, serum concentrations of leptin receptor, serum amyloid A, and estrogen correlate positively with FMC, and serum concentrations of leptin correlate negatively with FMC. The roles of adiponectin and prolactin in FMC development were also investigated, but the reports are either lacking or insufficient to suggest an association. Numerous research gaps were identified and could be used as opportunities for future research. These include the need for studies on additional cohorts to confirm the association of leptin/leptin receptor and serum amyloid A with FMC, and to address the role of adiponectin and prolactin in FMC. It is also important to investigate the genetic determinants of FMC, evaluate the use of molecular-targeted therapies in FMC, and exploit the enrichment of the triple-negative immunophenotype in FMC to address current clinical needs for both human triple-negative breast cancer and FMC. Finally, mechanistic studies with any of the molecules reviewed are scarce and are important to generate hypotheses and ultimately advance our knowledge and the outcome of FMC.

In Silico and In Vitro Evaluation of Bevacizumab Biosimilar MB02 as an Antitumor Agent in Canine Mammary Carcinoma

Canine mammary carcinomas (CMC) are associated with major aggressive clinical behavior and high mortality. The current standard of care is based on surgical resection, without an established effective treatment scheme, highlighting the urgent need to develop novel effective therapies. Vascular endothelial growth factor (VEGF) is a key regulator of tumor angiogenesis and progression in the majority of solid cancers, including human and canine mammary carcinomas. The first therapy developed to target VEGF was bevacizumab, a recombinant humanized monoclonal antibody, which has already been approved as an anticancer agent in several human cancers. The goal of this work was to establish the therapeutic value of MB02 bevacizumab biosimilar in CMC. First, through different in silico approaches using the MUSCLE multiple-sequence alignment tool and the FoldX protein design algorithm, we were able to predict that canine VEGF is recognized by bevacizumab, after showing an extremely high sequence similarity between canine and human VEGF. Further, by using an ELISA-based in vitro binding assay, we confirmed that MB02 biosimilar was able to recognize canine VEGF. Additionally, canine VEGF-induced microvascular endothelial cell proliferation was inhibited in a concentration-dependent manner by MB02 biosimilar. These encouraging results show a high potential for MB02 as a promising therapeutic agent for the management of CMC.

The protein and miRNA profile of plasma extracellular vesicles (EVs) can distinguish feline mammary adenocarcinoma patients from healthy feline controls

Feline mammary adenocarcinomas (FMA) are aggressive tumours with metastatic capability and limited treatment options. This study aims to investigate whether miRNAs associated with FMA tumours are secreted in extracellular vesicles (EVs) and whether they can potentially be used as a cancer biomarker in EVs from feline plasma. Tumours and matched tumour free margins from 10 felines with FMA were selected. Following a detailed literature search, RT-qPCR analyses of 90 miRNAs identified 8 miRNAs of interest for further investigation. Tumour tissue, margins and plasma were subsequently collected from a further 10 felines with FMA. EVs were isolated from the plasma. RT-qPCR expression analyses of the 8 miRNAs of interest were carried out in tumour tissue, margins, FMA EVs and control EVs. Additionally, proteomic analysis of both control and FMA plasma derived EVs was undertaken. RT-qPCR revealed significantly increased miR-20a and miR-15b in tumours compared to margins. A significant decrease in miR-15b and miR-20a was detected in EVs from FMAs compared to healthy feline EVs. The proteomic content of EVs distinguished FMAs from controls, with the protein targets of miR-20a and miR-15b also displaying lower levels in the EVs from patients with FMA. This study has demonstrated that miRNAs are readily detectable in both the tissue and plasma derived EVs from patients with FMA. These miRNAs and their protein targets are a detectable panel of markers in circulating plasma EVs that may inform future diagnostic tests for FMA in a non-invasive manner. Moreover, the clinical relevance of miR-20a and miR-15b warrants further investigation.

Realistic aspects behind the application of the rat model of chemically-induced mammary cancer: Practical guidelines to obtain the best results

Cancer is one of the most important public health problems worldwide. Despite the great contribution of in-vitro studies for biomedical research, animals are essential to study diseases' biopathology and diagnosis, and searching for new preventive and therapeutic strategies. Breast cancer is currently the most common cancer globally, accounting for 12.5% of all new annual cancer cases worldwide. Although the rat model of mammary cancer chemically-induced is widely used to study this disease, there is a lack of standardization in procedures for cancer induction, sample collection, and analysis. Therefore, it is important to provide a practical guide for researchers aiming to work with this model to make the analysis of results more uniform. Thus, in this review, we provide the researchers with a detailed step-by-step guide to implement a rat model of mammary cancer, based on our wide experience in this field, to obtain the best results, maximum throughput of each experiment, and easy comparison among researches.

Deregulated Expression of IL-37 in Patients with Bladder Urothelial Cancer: The Diagnostic Potential of the IL-37e Isoform

Cellular and molecular immune components play a crucial role in the development and perpetuation of human malignancies, shaping anti-tumor responses. A novel immune regulator is interleukin-37 (IL-37), already shown to be involved in the inflammation associated with the pathophysiology of many human disorders, including cancer. The interplay between tumor and immune cells is of great importance, especially for highly immunogenic tumors such as bladder urothelial carcinoma (BLCA). This study aimed to investigate the potential of IL-37 and its receptor SIGIRR (single immunoglobulin IL-1-related receptor) to serve as prognostic and/or diagnostic markers in patients with BLCA. To this end, a series of bioinformatics tools processing -omics datasets and specifically designed qPCR assays on human BLCA tumors and cancer cell lines were utilized. Bioinformatics analysis revealed that IL-37 levels correlate with BLCA tumor development and are higher in patients with longer overall survival. Furthermore, mutations on SIGIRR are associated with enhanced infiltration of the tumor by regulatory T cells and dendritic cells. Based on the qPCR validation experiments, BLCA epithelial cells express the IL-37c and IL-37e isoforms, while the latter is the predominant variant detected in tumor biopsies, also associated with higher grade and the non-muscle-invasive type. This is the first time, to the best of our knowledge, that IL-37 and SIGIRR levels have been assessed in BLCA tumor lesions, and associations with pathological and survival parameters are described, while a transcript variant-specific signature is indicated to have a diagnostic potential. These data strongly indicate the need for further investigation of the involvement of this cytokine and interconnected molecules in the pathophysiology of the disease and its prospective as a therapeutic target and biomarker for BLCA.

Single-Cell Analysis in Immuno-Oncology

The complexity of the cellular and non-cellular milieu surrounding human tumors plays a decisive role in the course and outcome of disease. The high variability in the distribution of the immune and non-immune compartments within the tumor microenvironments (TME) among different patients governs the mode of their response or resistance to current immunotherapeutic approaches. Through deciphering this diversity, one can tailor patients' management to meet an individual's needs. Single-cell (sc) omics technologies have given a great boost towards this direction. This review gathers recent data about how multi-omics profiling, including the utilization of single-cell RNA sequencing (scRNA-seq), assay for transposase-accessible chromatin with sequencing (scATAC-seq), T-cell receptor sequencing (scTCR-seq), mass, tissue-based, or microfluidics cytometry, and related bioinformatics tools, contributes to the high-throughput assessment of a large number of analytes at single-cell resolution. Unravelling the exact TCR clonotype of the infiltrating T cells or pinpointing the classical or novel immune checkpoints across various cell subsets of the TME provide a boost to our comprehension of adaptive immune responses, their antigen specificity and dynamics, and grant suggestions for possible therapeutic targets. Future steps are expected to merge high-dimensional data with tissue localization data, which can serve the investigation of novel multi-modal biomarkers for the selection and/or monitoring of the optimal treatment from the current anti-cancer immunotherapeutic armamentarium.

Prognostic value of soluble PD-L1 and exosomal PD-L1 in advanced gastric cancer patients receiving systemic chemotherapy

The prognostic role of soluble PD-L1 (sPD-L1) and exosomal PD-L1 (exoPD-L1) in patients with gastric cancer (GC) receiving systemic chemotherapy remains unelucidated. Thus, we examined their prognostic significance in patients with advanced GC. Blood samples were obtained from 99 patients with advanced GC receiving first-line chemotherapy. Serum-derived exosomes were isolated by centrifugation and polymer precipitation. The correlation between serum-derived exoPD-L1, plasma sPD-L1, immune-related markers, and circulating immune cells was evaluated. Patients were divided into two groups according to pretreatment sPD-L1 and exoPD-L1 levels: low sPD-L1 and high sPD-L1 groups, low exoPD-L1 and high exoPD-L1 groups. Patients with low sPD-L1 level before treatment (< 9.32 pg/mL) showed significantly better overall survival (OS) and progression-free survival (PFS) than those with high sPD-L1 level (≥ 9.32 pg/mL). The low exoPD-L1 group (< 10.21 pg/mL) showed a tendency of longer PFS than the high exoPD-L1 group (≥ 10.21 pg/mL). Pretreatment sPD-L1 was an independent prognostic factor for OS in multivariate analysis. exoPD-L1 was associated with systemic inflammation markers, immunomodulatory cytokines, and T cells, while sPD-L1 was associated with tumor markers. Pretreatment plasma-derived sPD-L1 level could be used as a prognostic marker for patients receiving cytotoxic chemotherapy. Serum-derived exoPD-L1 may reflect the immunosuppressive state of patients with advanced GC.

Autoimmunity and Carcinogenesis: Their Relationship under the Umbrella of Autophagy

The immune system and autophagy share a functional relationship. Both innate and adaptive immune responses involve autophagy and, depending on the disease’s origin and pathophysiology, it may have a detrimental or positive role on autoimmune disorders. As a “double-edged sword” in tumors, autophagy can either facilitate or impede tumor growth. The autophagy regulatory network that influences tumor progression and treatment resistance is dependent on cell and tissue types and tumor stages. The connection between autoimmunity and carcinogenesis has not been sufficiently explored in past studies. As a crucial mechanism between the two phenomena, autophagy may play a substantial role, though the specifics remain unclear. Several autophagy modifiers have demonstrated beneficial effects in models of autoimmune disease, emphasizing their therapeutic potential as treatments for autoimmune disorders. The function of autophagy in the tumor microenvironment and immune cells is the subject of intensive study. The objective of this review is to investigate the role of autophagy in the simultaneous genesis of autoimmunity and malignancy, shedding light on both sides of the issue. We believe our work will assist in the organization of current understanding in the field and promote additional research on this urgent and crucial topic.

Nano-baicalein facilitates chemotherapy in breast cancer by targeting tumor microenvironment

Cancer-associated fibroblasts constitute a significant component in the tumor microenvironment, playing a pivotal role in tumor proliferation, invasion, migration, and metastasis. Consequently, therapy combining chemotherapeutic agents with tumor microenvironment (TME) modulators appears to be a promising avenue for cancer treatment. In this paper, a tumor microenvironment-based mPEG-PLGA nanoparticle loaded with baicalein (PMs-Ba) was constructed for the purpose of improving the tumor microenvironment in cases of triple-negative breast cancer. The results demonstrate that, on the one hand, PMs-Ba was able to inhibit the transforming growth factor β(TGF-β) signaling pathway to avoid the activation of cancer-associated fibroblasts (CAFs), thereby influencing the interstitial microenvironment of the tumor. On the other hand, the agent led to an increase in the infiltration of cytotoxic T cells, activating the tumor immune microenvironment. Meanwhile, in the murine breast cancer model, an intravenous injection of PMs-Ba combined with doxorubicin nanoparticles (PMs-ADM) significantly improved the antitumor effectiveness. These results suggest that baicalein encapsulated in nanoparticles may be a promising strategy for modulating the TME and for adjuvant chemotherapy, signifying a potential TME-remodeling nanoformulation that could enhance the antitumor efficacy of nanotherapeutics.

Epithelial-to-Mesenchymal Transition and Phenotypic Marker Evaluation in Human, Canine, and Feline Mammary Gland Tumors

Epithelial-to-mesenchymal transition (EMT) is a process by which epithelial cells acquire mesenchymal properties. EMT has been closely associated with cancer cell aggressiveness. The aim of this study was to evaluate the mRNA and protein expression of EMT-associated markers in mammary tumors of humans (HBC), dogs (CMT), and cats (FMT). Real-time qPCR for SNAIL, TWIST, and ZEB, and immunohistochemistry for E-cadherin, vimentin, CD44, estrogen receptor (ER), progesterone receptor (PR), ERBB2, Ki-67, cytokeratin (CK) 8/18, CK5/6, and CK14 were performed. Overall, SNAIL, TWIST, and ZEB mRNA was lower in tumors than in healthy tissues. Vimentin was higher in triple-negative HBC (TNBC) and FMTs than in ER+ HBC and CMTs (p < 0.001). Membranous E-cadherin was higher in ER+ than in TNBCs (p < 0.001), whereas cytoplasmic E-cadherin was higher in TNBCs when compared with ER+ HBC (p < 0.001). A negative correlation between membranous and cytoplasmic E-cadherin was found in all three species. Ki-67 was higher in FMTs than in CMTs (p < 0.001), whereas CD44 was higher in CMTs than in FMTs (p < 0.001). These results confirmed a potential role of some markers as indicators of EMT, and suggested similarities between ER+ HBC and CMTs, and between TNBC and FMTs.

Acquired radioresistance in EMT6 mouse mammary carcinoma cell line is mediated by CTLA-4 and PD-1 through JAK/STAT/PI3K pathway

Cancer recurrence is often associated with the acquisition of radioresistance by cancer tissues due to failure in radiotherapy. The underlying mechanism leading to the development of acquired radioresistance in the EMT6 mouse mammary carcinoma cell line and the potential pathway involved was investigated by comparing differential gene expressions between parental and acquired radioresistance cells. EMT6 cell line was exposed to 2 Gy/per cycle of gamma-ray and the survival fraction between EMT6-treated and parental cells was compared. EMT6RR_MJI (acquired radioresistance) cells was developed after 8 cycles of fractionated irradiation. The development of EMT6RR_MJI cells was confirmed with further irradiation at different doses of gamma-ray, and both the survival fraction and migration rates were measured. Higher survival fraction and migration rates were obtained in EMT6RR_MJI cells after exposure to 4 Gy and 8 Gy gamma-ray irradiations compared to their parental cells. Gene expression between EMT6RR_MJI and parental cells was compared, and 16 genes identified to possess more than tenfold changes were selected and validated using RT-PCR. Out of these genes, 5 were significantly up-regulated i.e., IL-6, PDL-1, AXL, GAS6 and APCDD1. Based on pathway analysis software, the development of acquired radioresistance in EMT6RR_MJI was hypothesized through JAK/STAT/PI3K pathway. Presently, CTLA-4 and PD-1 were determined to be associated with JAK/STAT/PI3K pathway, where both their expressions were significantly increased in EMT6RR_MJI compared to parental cells in the 1st, 4th and 8th cycle of radiation. As a conclusion, the current findings provided a mechanistic platform for the development of acquired radioresistance in EMT6RR_MJI through overexpression of CTLA-4 and PD-1, and novel knowledge on therapeutic targets for recurrent radioresistant cancers.

TIM-3 Is a Potential Immune Checkpoint Target in Cats with Mammary Carcinoma

Recent findings in human breast cancer (HBC) indicate that T-cell immunoglobulin and mucin-domain-containing molecule-3 (TIM-3)-targeted therapies may effectively activate anticancer immune responses. Although feline mammary carcinoma (FMC) is a valuable cancer model, no studies on TIM-3 have been developed in this species. Thus, we evaluated the expression of TIM-3 by immunohistochemistry in total (t), stromal (s), and intra-tumoral (i) tumor-infiltrating lymphocytes (TILs) and in cancer cells, of 48 cats with mammary carcinoma. In parallel, serum TIM-3 levels were quantified using ELISA and the presence of somatic mutations in the TIM-3 gene was evaluated in 19 tumor samples. sTILs-TIM3+ were more frequent than iTILs-TIM-3+, with the TIM-3 ex-pression in sTILs and cancer cells being associated with more aggressive clinicopathological features. In contrast, the TIM-3 expression in iTILs and tTILs was associated with a more benign clinical course. Moreover, the serum TIM-3 levels were lower in animals with FMC when compared to healthy animals (p < 0.001). Only one somatic mutation was found in the TIM-3 gene, at intron 2, in one tumor sample. Altogether, our results suggest that the expression of TIM-3 among TILs subpopulations and cancer cells may influence the clinical outcome of cats with FMC, in line with the previous reports in HBC.

Elevated circulating Hsp70 levels are correlative for malignancies in different mammalian species

Circulating Hsp70 levels were determined in feline and porcine cohorts using two different ELISA systems. These comparative animal models of larger organisms often reflect diseases, and especially malignant tumors, better than conventional rodent models. It is therefore essential to investigate the biology and utility of tumor biomarkers in animals such as cats and pigs. In this study, levels of free Hsp70 in the blood of cats with spontaneously occurring tumors were detected using a commercial Hsp70 ELISA (R&D Systems). Sub-analysis of different tumor groups revealed that animals with tumors of epithelial origin presented with significantly elevated circulating Hsp70 concentrations. In addition to free Hsp70 levels measured with the R&D Systems Hsp70 ELISA, levels of exosomal Hsp70 were determined using the compHsp70 ELISA in pigs. Both ELISA systems detected significantly elevated Hsp70 levels (R&D Systems: median 24.9 ng/mL; compHsp70: median 44.2 ng/mL) in the blood of a cohort of APC1311/+ pigs diagnosed with high-grade adenoma polyps, and the R&D Systems Hsp70 ELISA detected also elevated Hsp70 levels in animals with low-grade polyps. In contrast, in flTP53R167H pigs, suffering from malignant osteosarcoma, the compHsp70 ELISA (median 674.32 ng/mL), but not the R&D Systems Hsp70 ELISA (median 4.78 ng/mL), determined significantly elevated Hsp70 concentrations, indicating that in tumor-bearing animals, the dominant form of Hsp70 is of exosomal origin. Our data suggest that both ELISA systems are suitable for detecting free circulating Hsp70 levels in pigs with high-grade adenoma, but only the compHsp70 ELISA can measure elevated, tumor-derived exosomal Hsp70 levels in tumor-bearing animals.

The Role of Mesenchymal Stem Cells in Modulating the Breast Cancer Microenvironment

The role of mesenchymal stem cells (MSCs) in the breast tumor microenvironment (TME) is significant and multifaceted. MSCs are recruited to breast tumor sites through molecular signals released by tumor sites. Once in the TME, MSCs undergo polarization and interact with various cell populations, including immune cells, cancer-associated fibroblasts (CAFs), cancer stem cells (CSCs), and breast cancer cells. In most cases, MSCs play roles in breast cancer therapeutic resistance, but there is also evidence that indicates their abilities to sensitize cancer cells to chemotherapy and radiotherapy. MSCs possess inherent regenerative and homing properties, making them attractive candidates for cell-based therapies. Therefore, MSCs can be engineered to express therapeutic molecules or deliver anti-cancer agents directly to tumor sites. Unraveling the intricate relationship between MSCs and the breast TME has the potential to uncover novel therapeutic targets and advance our understanding of breast cancer biology.

Aberrant Expression and Prognostic Potential of IL-37 in Human Lung Adenocarcinoma

Interleukin-37 (IL-37) is a relatively new IL-1 family cytokine that, due to its immunoregulatory properties, has lately gained increasing attention in basic and translational biomedical research. Emerging evidence supports the implication of this protein in any human disorder in which immune homeostasis is compromised, including cancer. The aim of this study was to explore the prognostic and/or diagnostic potential of IL-37 and its receptor SIGIRR (single immunoglobulin IL-1-related receptor) in human tumors. We utilized a series of bioinformatics tools and -omics datasets to unravel possible associations of IL-37 and SIGIRR expression levels and genetic aberrations with tumor development, histopathological parameters, distribution of tumor-infiltrating immune cells, and survival rates of patients. Our data revealed that amongst the 17 human malignancies investigated, IL-37 exhibits higher expression levels in tumors of lung adenocarcinoma (LUAD). Moreover, the expression profiles of IL-37 and SIGIRR are associated with LUAD development and tumor stage, whereas their high mRNA levels are favorable prognostic factors for the overall survival of patients. What is more, IL-37 correlates positively with a LUAD-associated transcriptomic signature, and its nucleotide changes and expression levels are linked with distinct infiltration patterns of certain cell subsets known to control LUAD anti-tumor immune responses. Our data indicate the potential value of IL-37 and its receptor SIGIRR to serve as biomarkers and/or immune-checkpoint therapeutic targets for LUAD patients. Further, the data highlight the urgent need for further exploration of this cytokine and the underlying pathogenetic mechanisms to fully elucidate its implication in LUAD development and progression.

The modulatory role of dendritic cell-T cell cross-talk in breast cancer: Challenges and prospects

Antigen recognition and presentation are highlighted as the first steps in developing specialized antigen responses. Dendritic cells (DCs) are outstanding professional antigen-presenting cells (APCs) responsible for priming cellular immunity in pathological states, including cancer. However, the diminished or repressed function of DCs is thought to be a substantial mechanism through which tumors escape from the immune system. In this regard, DCs obtained from breast cancer (BC) patients represent a notably weakened potency to encourage specific T-cell responses. Additionally, impaired DC-T-cell cross-talk in BC facilitates the immune evade of cancer cells and is connected with tumor advancement, immune tolerance, and adverse prognosis for patients. In this review we aim to highlight the available knowledge on DC-T-cell interactions in BC aggressiveness and show its therapeutic potential in BC treatment.

Exosomes in the tumor microenvironment of sarcoma: from biological functions to clinical applications

The current diagnosis and treatment of sarcoma continue to show limited timeliness and efficacy. In order to enable the early detection and management of sarcoma, increasing attentions have been given to the tumor microenvironment (TME). TME is a dynamic network composed of multiple cells, extracellular matrix, vasculature, and exosomes. Exosomes are nano-sized extracellular vesicles derived from various cells in the TME. The major function of exosomes is to promote cancer progress and metastasis through mediating bidirectional cellular communications between sarcoma cells and TME cells. Due to the content specificity, cell tropism, and bioavailability, exosomes have been regarded as promising diagnostic and prognostic biomarkers, and therapeutic vehicles for sarcoma. This review summarizes recent studies on the roles of exosomes in TME of sarcoma, and explores the emerging clinical applications.

Differential distribution and prognostic value of CD4+ T cell subsets before and after radioactive iodine therapy in differentiated thyroid cancer with varied curative outcomes

Differentiated thyroid cancer is the most frequently diagnosed endocrine tumor. While differentiated thyroid cancers often respond to initial treatment, little is known about the differences in circulating immune cells amongst patients who respond differently. A prospective study of 39 patients with differentiated thyroid cancer was conducted. Serum thyroglobulin levels and thyroid and immunological functions were tested before and after radioactive iodine treatment (RAIT). Efficacy assessments were performed 6 to 12 months after radioactive iodine treatment. Most patients showed an excellent response to radioactive iodine treatment. Before radioactive iodine treatment, the excellent response group had considerably fewer circulating CD4⁺ T cell subsets than the non-excellent response group. Both the excellent response and non-excellent response groups had considerably lower circulating CD4⁺ T lymphocyte subsets 30 days after radioactive iodine treatment, but those of the excellent response group were still lower than those of the non-excellent response group. All circulating CD4⁺ T cell subsets in the excellent response group rose by varying degrees by the 90th day, but only Treg cell amounts increased in the non-excellent response group. Interestingly, in the non-excellent response group, we noticed a steady drop in Th1 cells. However, the bulk of circulating CD4⁺ T cell subsets between the two groups did not differ appreciably by the 90th day. Finally, we discovered that CD4⁺ T cell subsets had strong predictive potential, and we thus developed high-predictive-performance models that deliver more dependable prognostic information. In conclusion, in individuals with differentiated thyroid cancer, there is great variation in circulating immune cells, resulting in distinct treatment outcomes. Low absolute CD4⁺ T cell counts is linked to improved clinical outcomes as well as stronger adaptive and resilience capacities.

The Landscape of Tumor-Infiltrating Immune Cells in Feline Mammary Carcinoma: Pathological and Clinical Implications

Feline mammary carcinoma (FMC) shares key molecular and clinicopathological features with human breast cancer. We have herein studied the inflammatory infiltrate of FMC in order to uncover potential therapeutic targets and prognostic markers. To this end, the expression of different markers (CD3, CD4, CD8, CD20, CD56, FoxP3, CD68 and CD163) was analyzed in total, stromal (s) and intratumoral (i) tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs), in 73 feline mammary carcinomas. The results revealed that higher percentages of sCD8⁺ TILs were associated with longer disease-free survival (p = 0.05) and overall survival (p = 0.021). Additionally, higher percentages of iCD4⁺ TILs correlated with positive lymph node status (p = 0.003), whereas CD163⁺ TAMs were associated with undifferentiated tumors (p = 0.013). In addition, sCD3⁺ (p = 0.033), sCD8⁺ (p = 0.044) and sCD68⁺ (p = 0.023) immune cells were enriched in triple negative normal-like carcinomas compared to other subtypes. Altogether, our results suggest that specific subsets of immune cells may play a major role in clinical outcome of cats with mammary carcinoma, resembling what has been reported in human breast cancer. These data further support the relevance of the feline model in breast cancer studies.

Trends in Small Animal Reproduction: A Bibliometric Analysis of the Literature

Simple Summary

Reproduction in small animals is an expanding research area, with focus on breeding improvement and clinical management of domestic carnivores. The aim of the present study was to conduct a bibliometric analysis of the literature of the last decade on small animal reproduction, to point out main sources, most prolific countries, and emerging and neglected topics. Results show that research in biotechnologies for assisted reproduction has a central and increasing role in this field. Diversity in author keywords was also pointed out and a consensus to better categorize research in this field is proposed to reduce this problem in the future.

Abstract

Small animal reproduction (SAR) is a main research field in veterinary medicine and bibliometric analyses are useful to investigate trends in specific research areas. The objective of the present study was to conduct a bibliometric analysis of the literature of the last decade on SAR. A search equation was created, and documents were retrieved from the Web of Science database. Documents were manually revised, categorized and R software version 4.1.2 with Bibliometrix R package version 3.1 and MS Excel were used to perform the analyses. The included documents (n = 1470) were mainly research articles (78%). The top countries for the number of documents and citations were Brazil, United States, Italy, Poland, and Korea. These also account for the most prolific authors and institutions. Analyses by author keywords, categories, and recent reviews of the literature suggest that research on the canine species is more abundant than research on the feline one and that reproductive biotechnologies are a main research focus. Some clinical topics are still considered niche or neglected themes (e.g., semen collection in tomcats, neonatology). However, heterogeneity and ambiguity in keywords and categories are undeniable. This study offers interesting insights, providing definitions for main keywords in the field of SAR.

Identification of a Lipid Metabolism-Associated Gene Signature Predicting Survival in Breast Cancer

Background

Cancer metabolism and specifically lipid metabolism play an important role in breast cancer (BC) progression and metastasis. However, the role of lipid metabolism-associated genes (LMGs) in the prognosis of breast cancer remains unknown.

Methods

The expression profiles and clinical follow-up information of 1053 BC were downloaded from The Cancer Genome Atlas (TCGA), and metabolic genes were downloaded from the Gene Set Enrichment Analysis (GSEA) dataset. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression analyses were performed on the differentially expressed metabolism-related genes. Then, the formula of the metabolism-related risk model was composed, and the risk score of each patient was calculated. The breast cancer patients were divided into high-risk and low-risk groups with a cutoff of the median expression value of the risk score, and the prognostic analysis was also used to analyze the survival time between these two groups. Finally, we analyzed the expression, interaction and correlation among the lipid metabolism-associated genes risk model.

Results

The results from the prognostic analysis indicated that the survival was significantly poorer in the high-risk group than in the low-risk group in TCGA, and single-sample gene set enrichment analysis (ssGSEA) shows it is plausible that lipid metabolism is highly correlated with tumor immunity.

Conclusion

Lipid metabolism-associated genes may become a new prognostic indicator predicting the survival of BC patients. The prognostic genes (n = 16) may help provide new strategies for tumor therapy.

CXCL8 is a prognostic biomarker and correlated with TNBC brain metastasis and immune infiltration

Patients with TNBC are associated with an increased risk of developing brain metastasis and shortest median survival post-brain metastasis-diagnosis. However, the regulatory mechanism of TNBC brain metastasis has not been addressed. Here, by a series of integrated analyses of differential gene expression profile from brain metastases and primary triple negative breast cancer, we identified 15 differentially expressed genes in both TNBC brain metastasis tissue samples and TNBC brain metastasis cell line. After analyzing the prognostic value of those 15 differentially expressed genes, we found that CXCL8 was the only gene associated with multiple prognostic indicators in both all-breast cancer and TNBC populations. Functional and pathway enrichment analyses demonstrated that CXCL8 was associated with humoral immune response and immune cell infiltration. CXCL8 expression had a positive correlation with three immune-related scores (ImmuneScore, ESTIMATEScore and StromalScore), and multiple types of immune cell infiltration, including macrophages, neutrophils and Th1 cells. Besides, we also verified the prometastatic effect of CXCL8, by treating MDA-MB-231 and Hs578t cells with different concentrations of recombinant human CXCL8. Taken together, our results suggest that CXCL8 can be used as a prognostic biomarker and is associated with TNBC brain metastasis and immune infiltration. Our findings provide a new perspective on TNBC brain metastasis and illustrate great potential to develop new CXCL8-targeted therapy for clinical TNBC patients.