Targeting the Tumor Vascular Supply to Enhance Radiation Therapy Administered in Single or Clinically Relevant Fractionated Schedules.

This pre-clinical study was designed to demonstrate how vascular disrupting agents (VDAs) should be administered, either alone or when combined with radiation in clinically relevant fractionated radiation schedules, for the optimal anti-tumor effect. CDF1 mice, implanted in the right rear foot with a 200 mm3 murine C3H mammary carcinoma, were injected with various doses of the most potent VDA drug, combretastatin A-1 phosphate (CA1P), under different schedules. Tumors were also locally irradiated with single-dose, or stereotactic (3 × 5-20 Gy) or conventional (30 × 2 Gy) fractionation schedules. Tumor growth and control were the endpoints used. Untreated tumors had a tumor growth time (TGT5; time to grow to 5 times the original treatment volume) of around 6 days. This increased with increasing drug doses (5-100 mg/kg). However, with single-drug treatments, the maximum TGT5 was only 10 days, yet this increased to 19 days when injecting the drug on a weekly basis or as three treatments in one week. CA1P enhanced radiation response regardless of the schedule or interval between the VDA and radiation. There was a dose-dependent increase in radiation response when the combined with a single, stereotactic, or conventional fractionated irradiation, but these enhancements plateaued at around a drug dose of 25 mg/kg. This pre-clinical study demonstrated how VDAs should be combined with clinically applicable fractionated radiation schedules for the optimal anti-tumor effect, thus suggesting the necessary pre-clinical testing required to ultimately establish VDAs in clinical practice.

Exploring Canine Mammary Cancer through Liquid Biopsy: Proteomic Profiling of Small Extracellular Vesicles.

(Background). Canine mammary tumors (CMTs) have emerged as an important model for understanding pathophysiological aspects of human disease. Liquid biopsy (LB), which relies on blood-borne biomarkers and offers minimal invasiveness, holds promise for reflecting the disease status of patients. Small extracellular vesicles (SEVs) and their protein cargo have recently gained attention as potential tools for disease screening and monitoring. (Objectives). This study aimed to isolate SEVs from canine patients and analyze their proteomic profile to assess their diagnostic and prognostic potential. (Methods). Plasma samples were collected from female dogs grouped into CMT (malignant and benign), healthy controls, relapse, and remission groups. SEVs were isolated and characterized using ultracentrifugation (UC), nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Proteomic analysis of circulating SEVs was conducted using liquid chromatography-mass spectrometry (LC-MS). (Results). While no significant differences were observed in the concentration and size of exosomes among the studied groups, proteomic profiling revealed important variations. Mass spectrometry identified exclusive proteins that could serve as potential biomarkers for mammary cancer. These included Inter-alpha-trypsin inhibitor heavy chain (ITIH2 and ITI4), phosphopyruvate hydratase or alpha enolase (ENO1), eukaryotic translation elongation factor 2 (eEF2), actin (ACTB), transthyretin (TTR), beta-2-glycoprotein 1 (APOH) and gelsolin (GSN) found in female dogs with malignant tumors. Additionally, vitamin D-binding protein (VDBP), also known as group-specific component (GC), was identified as a protein present during remission. (Conclusions). The results underscore the potential of proteins found in SEVs as valuable biomarkers in CMTs. Despite the lack of differences in vesicle concentration and size between the groups, the analysis of protein content revealed promising markers with potential applications in CMT diagnosis and monitoring. These findings suggest a novel approach in the development of more precise and effective diagnostic tools for this challenging clinical condition.

Immunohistochemical Detection of Indoleamine 2,3-Dioxygenase in Spontaneous Mammary Carcinomas of 96 Pet Rabbits.

For mammary carcinomas in pet rabbits, prognostic biomarkers are poorly defined, and treatment is limited to surgical excision. Additional treatment options are needed for rabbit patients for which surgery is not a suitable option. In human breast cancer, the immunosuppressive enzyme indoleamine 2,3-dioxygenase 1 (IDO1) represents a prognostic biomarker and possible therapeutic target. This retrospective immunohistochemical study examined IDO1 in 96 pet rabbit mammary carcinomas with known mitotic count, hormone receptor status, and percentage of stromal tumor infiltrating lymphocytes (TILs). Tumors were obtained from 96 pet rabbits with an average of 5.5 years. All rabbits with reported sex (n = 88) were female or female-spayed. Of the carcinomas, 94% expressed IDO1, and 86% had sparse TILs consistent with cold tumors. Statistically significant correlations existed between a higher percentage of IDO1-positive tumor cells, lower mitotic counts, and increased estrogen receptor expression. The threshold for significance was IDO1 staining in >10% of tumor cells. These results lead to the assumption that IDO1 expression contributes to tumorigenesis and may represent a prognostic biomarker and possible therapeutic target also in pet rabbit mammary carcinomas. They also support the value of rabbits for breast cancer research.

Advances in immunotherapy for breast cancer and feline mammary carcinoma: From molecular basis to novel therapeutic targets.

The role of inflammation in cancer is a topic that has been investigated for many years. As established, inflammation emerges as a defining characteristic of cancer, presenting itself as a compelling target for therapeutic interventions in the realm of oncology. Controlling the tumor microenvironment (TME) has gained paramount significance, modifying not only the effectiveness of immunotherapy but also modulating the outcomes and prognoses of standard chemotherapy and other anticancer treatments. Immunotherapy has surfaced as a central focus within the domain of tumor treatments, using immune checkpoint inhibitors as cancer therapy. Immune checkpoints and their influence on the tumor microenvironment dynamic are presently under investigation, aiming to ascertain their viability as therapeutic interventions across several cancer types. Cancer presents a significant challenge in humans and cats, where female breast cancer ranks as the most prevalent malignancy and feline mammary carcinoma stands as the third most frequent. This review seeks to summarize the data about the immune checkpoints cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), lymphocyte activation gene-3 (LAG-3), programmed cell death protein-1 (PD-1), V-domain Ig suppressor of T cell activation (VISTA), and T-cell immunoglobulin and mucin domain 3 (TIM-3) respective ongoing investigations as prospective targets for therapy for human breast cancer, while also outlining findings from studies reported on feline mammary carcinoma (FMC), strengthening the rationale for employing FMC as a representative model in the exploration of human breast cancer.

Mammary neoplasms in female dogs: Clinical, diagnostic and therapeutic aspects.

With the increase in the life expectancy of domestic animals and their increasingly affectionate relationship with their owners, it is possible to observe an increase in cases of neoplasms in these animals. Mammary neoplasia mainly affects older females who have not been castrated, due to hormonal dependence for the development of the tumour. The main form of treatment is surgery. This study aims to carry out an updated review on mammary neoplasms in female dogs covering the anatomy, physiology, prevalence, causes, diagnoses, treatments, prevention and prognosis, based on scientific articles by renowned researchers.

Efficacy of IFN-γ, sCD40L, and Poly(I:C) Treated Bone Marrow-Derived Macrophages in Murine Mammary Carcinoma.

INTRODUCTION: Here, we explored methods to generate anti-tumor bone marrow-derived macrophages (BMDM) and how delivery of the BMDM at early tumor sites could impact disease progression. METHODS: BMDM treated with IFN-γ, sCD40L, poly(I:C), and a combination of the three were assessed. RESULTS: Treatment with sCD40L had no significant impact on the BMDM. Treating BMDM with IFN-γ impacted IL-1ß, MHC Class II, and CD80 expression. While poly(I:C) treatment had a greater impact on the BMDM than IFN-γ when assessed by the in vitro assays, the BMDM treated with poly (I:C) had mixed results in vivo where they decreased growth of the EMT6 tumor, did not impact growth of the 168 tumor, and enhanced growth of the 4T1 tumor. The combination of poly(I:C), IFN-γ, and sCD40L had the greatest impact on the BMDM in vitro and in vivo. Treatment with all three agonists resulted in increased IL-1ß, TNF-α, and IL-12 expression, decreased expression of arginase and mrc, increased phagocytic activity, nitrite production, and MHC Class II and CD80 expression, and significantly impacted growth of the EMT6 and 168 murine mammary carcinoma models. DISCUSSION: Collectively, these data show that treating BMDM with poly(I:C), IFN-γ, and sCD40L generates BMDM with more consistent anti-tumor activity than BMDM generated with the individual agonists.

Reduction of phosphorylated signal transducer and activator of transcription-5 expression in feline mammary carcinoma.

Signal transducers and activators of transcription (STATs) are a family of transcription factors involved in various normal physiological cellular processes. Moreover, STATs have been recently identified as novel therapeutic targets for various human tumors. STAT3, STAT5a, and STAT6 have been suggested to be involved in tumorigenesis in human breast cancer. Owing to the similarity between feline mammary carcinomas (FMCs) and human breast cancers, these factors may play an important role in FMCs. However, studies on the expression of STATs in animal tumors are limited. Therefore, in this study, we aimed to characterize the expression of total STAT5 (tSTAT5) and phosphorylated STAT5 (pSTAT5) in FMCs, feline mammary adenomas, non-neoplastic proliferative mammary gland lesions, and normal feline mammary glands using immunohistochemistry. High expression of tSTAT5 was observed in the cytoplasm of all the samples assessed in this study. Moreover, high expression of tSTAT5 was observed in the nucleus; however, its levels varied depending on the lesion. The percentage of pSTAT5-nuclear positive cells varied among normal feline mammary glands (40.1 ± 25.1%), and non-neoplastic lesions, including mammary hyperplasia (43.2 ± 28.6%) and fibroadenomatous changes (18.0 ± 13.6%). Moreover, the percentage of pSTAT5-nuclear-positive cells in feline mammary adenomas was 24.5 ± 19.2%, which was significantly reduced in feline mammary carcinomas (2.4 ± 5.6%), regardless of histopathological subtype. This study suggests that decreased STAT5 activity may be involved in the development and malignant progression of feline mammary carcinomas.

Intranodal Injection of Immune Activator Demonstrates Antitumor Efficacy in an Adjuvant Approach.

The tumor-draining lymph nodes (tdLN) are the initial site of metastases and are the prime site for generating robust antitumor responses. In this study, we explored the efficacy of a universal immune activator (ImmAct) targeted to the tdLN. This approach can be viewed as an attempt to turn a cold, unresponsive tdLN into a hot, responsive site. The adjuvant antitumor efficacy of our novel intranodal injection was evaluated in an aggressive metastatic mammary carcinoma murine model. The cancer cells were inoculated subcutaneously in the lower quadrant of the mouse to provoke the tdLN (inguinal lymph node). The study encompasses a range of methodologies, including in vivo and in vitro assays and high-dimensional flow cytometry analysis. Our findings demonstrated that intranodal administration of ImmAct following the dissection of the primary tumor led to improved tumor-free survival and minimized weight loss. ImmAct led to both local and systemic alterations in the cellular and humoral immunity. Additionally, after ImmAct treatment, non-responders showed a higher rate of exhausted CD8+ T cells compared to responders. Indeed, our innovative approach surpassed the gold standard surgery of sentinel lymph node excision. Overall, intranodal administration of ImmAct yielded a robust antitumor immune response, offering protection against micrometastases and relapse.

Pathological findings of mammary gland carcinoma and hemangiosarcoma cases in two African wild dogs (Lycaon pictus).

There are few studies on diseases affecting endangered African wild dogs. We report our findings on malignant tumors in two African wild dogs. Case 1 was a 6-year-old intact female diagnosed with inflammatory mammary carcinoma with pulmonary metastasis. Case 2 was an 11-year-old male diagnosed with primary hemangiosarcoma of the left atrial coronary sulcus with metastasis to multiple organs. Additionally, the tumor had grown through the cardiac wall, causing cardiac tamponade. The identification of disease incidence trends provides important information which will allow for the early detection and treatment of malignant tumors, and aid in the conservation of this species.

Estrogen receptors alpha and beta expression in different canine cancer types with an emphasis on hematopoietic malignancies.

Estrogen receptors (ERs) are located in both healthy and neoplastic tissues. The type of estrogen receptor expressed varies depending on its location, tumor type, and species. Estrogen action is mediated by binding to ER and activating the transcriptional and signaling processes that result in the control of gene expression. There are two main types of estrogen receptors: ER alpha (ERα) and ER beta (ERß). Both receptors are functionally different, they may act antagonistically and are distributed in different tissues but their structure is similar - as they are composed of 5 different domains: A/B, C, D, E, and F. The signaling pathway and hence regulation of the gene expression by ERs is a complex and multifactorial process that involves both genomic and nongenomic actions. In the human reproductive tract, both ERα and ß are present, with predominant expression of ERß, while there are no satisfactory data distinguishing the type of ERs expressed in the canine reproductive tract. In mammary gland neoplasia, a decreased or lacking ERα expression in humans is associated with a poorer prognosis. This is similar to dogs, where higher ERα expression intensity was noted in benign tumors than in carcinomas. In human hematopoietic malignancies, ERß is a predominant receptor. Selective and non-selective ERß agonists have an antiproliferative and pro-apoptotic effect on human lymphoma cell lines and may be effective in the therapy of ERß positive lymphomas and leukemias. In canine lymphoma tissues, none or only marginal expression of ERs was detected over the decades. Considering available data, we conducted preliminary studies proving that, in contrast to humans, the dominant ER expressed in canine hematopoietic tumors is ERα.

The Impact of miRNAs on the Efficacy of Tamoxifen in Breast Cancer Treatment: A Systematic Review.

Seventy percent of breast cancer patients have an active estrogen receptor. Tamoxifen interferes with estrogen's ability to bind to cancer cells. The most challenging aspect of tamoxifen, however, is that breast cancer cells become resistant to its effects. Some studies have shown that alterations in miRNA expression contribute significantly to drug resistance in breast cancer. Therefore, the present systematic review aims to investigate miRNAs that significantly influence the response to tamoxifen treatment. The present study follows the PRISMA instructions. The Web of Science, PubMed, and Scopus databases were searched to retrieve English articles. The searches were conducted up to September 11, 2022. The search strategy included the terms "Tamoxifen", "Breast Neoplasm", and "MicroRNA". The inclusion criteria of this study are English, original, and experimental studies investigating miRNAs that are effective in the treatment efficacy of tamoxifen. A total of 565 articles were retrieved. After screening, 75 studies met our inclusion criteria. This systematic review study examined 105 miRNAs, of which 44 have a positive effect, and 47 miRNAs inhibit tamoxifen function. Fourteen miRNAs have a controversial effect, ie, some studies show positive and negative effects. The study of miRNAs affecting tamoxifen function in breast cancer patients may facilitate the identification of individuals at higher risk of disease recurrence. Conversely, it can potentially utilize appropriate interventions to defeat drug resistance effectively.

Exosomes from Adipose-Tissue-Derived Stem Cells Induce Proapoptotic Gene Expression in Breast Tumor Cell Line.

Lipofilling is an option for breast reconstruction after tumor resection to avoid the complications of an implant-based reconstruction. Although some concerns exist regarding the oncological safety of tissue rich in mesenchymal stem cells with their proangiogenic and proliferation-supportive properties, there are also reports that adipose-tissue-derived stem cells can exhibit antitumoral properties. We isolated primary adipose-tissue-derived stem cells. Both conditioned medium and exosomes were harvested from the cell culture and used to treat the breast cancer cell line MCF-7. Cell viability, cytotoxicity, and gene expression of MCF-7 cells in response to the indirect co-culture were evaluated. MCF-7 cells incubated with exosomes from adipose-tissue-derived stem cells show reduced cell viability in comparison to MCF-7 cells incubated with adipose-tissue-derived stem-cell-conditioned medium. Expression of proapoptotic genes was upregulated, and expression of antiapoptotic genes was downregulated. The debate about the oncological safety of autologous fat grafting after tumor resection continues. Here, we show that exosomes from adipose-tissue-derived stem cells exhibit some antitumoral properties on breast cancer cell line MCF-7.

Molecular Characterization and Subtyping of Breast Cancer Cell Lines Provide Novel Insights into Cancer Relevant Genes.

Continuous cell lines are important and commonly used in vitro models in breast cancer (BC) research. Selection of the appropriate model cell line is crucial and requires consideration of their molecular characteristics. To characterize BC cell line models in depth, we profiled a panel of 29 authenticated and publicly available BC cell lines by mRNA-sequencing, mutation analysis, and immunoblotting. Gene expression profiles separated BC cell lines in two major clusters that represent basal-like (mainly triple-negative BC) and luminal BC subtypes, respectively. HER2-positive cell lines were located within the luminal cluster. Mutation calling highlighted the frequent aberration of TP53 and BRCA2 in BC cell lines, which, therefore, share relevant characteristics with primary BC. Furthermore, we showed that the data can be used to find novel, potential oncogenic fusion transcripts, e.g., FGFR2::CRYBG1 and RTN4IP1::CRYBG1 in cell line MFM-223, and to elucidate the regulatory circuit of IRX genes and KLF15 as novel candidate tumor suppressor genes in BC. Our data indicated that KLF15 was activated by IRX1 and inhibited by IRX3. Moreover, KLF15 inhibited IRX1 in cell line HCC-1599. Each BC cell line carries unique molecular features. Therefore, the molecular characteristics of BC cell lines described here might serve as a valuable resource to improve the selection of appropriate models for BC research.

PD-L1 mRNA and protein expression in canine mammary carcinomas: Correlation with histopathological grade and molecular markers.

Programmed death ligand 1 (PD-L1) is an immune checkpoint molecule that plays a crucial role in regulating antitumor immune responses. Canine mammary carcinomas (CMCs) are common tumors of dogs. Despite extensive studies on the heterogeneity of CMCs, there is still a lack of effective precision therapies for the treatment of CMCs. In this study, we aimed to investigate the correlation between PD-L1 mRNA and protein expression in CMCs and explore its association with histopathological grade and molecular markers, including the estrogen receptor, epidermal growth factor receptor 2, and cytokeratin 5/6 (CK5/6). Formalin-fixed paraffin-embedded samples were evaluated for PD-L1 mRNA expression using RNA in situ hybridization and PD-L1 protein expression using immunohistochemistry. We observed no substantial correlation between PD-L1 mRNA and protein expression in CMCs; however, PD-L1 mRNA levels were significantly higher in grade 3 than in grade 1 tumors (P = .001). In addition, we observed a positive correlation between PD-L1 protein expression and CK5/6 expression in CMCs (P = .032). These findings suggest that PD-L1 expression in CMCs is heterogeneous and may be regulated post-transcriptionally. Further studies are needed to explore the prognostic and therapeutic implications of PD-L1 expression in different molecular subtypes of CMCs and their potential as predictive biomarkers for immunotherapy.

Maintenance of Aerobic or Resistance Training After an Exercise Intervention Among Breast Cancer Patients After Neoadjuvant Chemotherapy.

BACKGROUND: Exercise interventions have been shown to be beneficial for cancer patients regarding various treatment-related side effects and quality of life. For sustainable effects, patients should continue the training. Therefore, we investigated the maintenance of an exercise training in breast cancer patients, reasons for (dis)continuation, and explored possible influencing factors. METHODS: The investigation is based on a 3-arm randomized intervention trial comparing aerobic and resistance training (19 [4]) during or after neoadjuvant chemotherapy among breast cancer patients. About 2 years after breast surgery, 68 patients (age 52 [11] y) provided information about training continuation, self-reported reasons of (dis)continuation, sociodemographics, employment status, age, and body mass index. Training continuation was investigated with Kaplan-Meier analyses. RESULTS: The intervention was rated as good or very good by 88.1% of participants. Nevertheless, 52.9% discontinued the training directly, but half of them changed to different types of exercise. Reasons for discontinuation included lack of time and long travel distance to the training facility. The median continuation was 19.0 months (Q1, Q3: 5.5, 36.0) with no statistically significant difference between the intervention groups. Younger, better educated, partnered patients tended toward longer training continuation. CONCLUSIONS: The majority of patients continued exercising after the end of intervention. However, a nonnegligible number discontinued training immediately or after few months. Practical, social, and financial support for a transition to an adequate training that is affordable and feasible in the patient's daily life might foster training maintenance. Especially patients who are less educated, elderly, or living alone may need more support to continue exercising.

Homoharringtonine induces apoptosis of mammary carcinoma cells by inhibiting the AKT/mTOR signaling pathway.

Mammary tumour is the most common type of tumour in dogs, especially in unneutered female dogs. Homoharringtonine (HHT) is a natural alkaloid that can be used to treat various types of human tumour. However, the inhibitory effect and mechanism of HHT on canine mammary carcinomas (CMC) remain unclear. This study aimed to evaluate the inhibitory effect of HHT on CMC in vitro and determine its underlying molecular mechanism. The effects of HHT on the cytotoxicity of CMC U27 cells were evaluated by the cell counting kit-8, wound healing, and Transwell assays. HHT-induced apoptosis of U27 cells was detected by JC-1 and terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay. Moreover, the gene expression of B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) were analysed using quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and the protein expression of protein kinase B/mammalian target of rapamycin (AKT/mTOR) and mitochondrial apoptosis proteins were determined by western blotting. Furthermore, mammary tumour-bearing mouse models were established using 4T1 cells to evaluate the therapeutic effect of HHT. It was found that HHT could significantly down-regulated the protein expression of p-AKT, p-mTOR, and Bcl-2, and up-regulated the protein expression of P53, Bax, cleaved caspase-3, and cleaved caspase-9. In addition, HHT significantly suppressed both tumour volume and mass in mammary tumour mice. In conclusion, HHT damages CMC cells by inhibiting the AKT/mTOR signalling pathway and inducing mitochondrial apoptosis. Such findings lay a theoretical foundation for the clinical treatment of CMC and provide more options for clinical medication.

Antitumor activity and targeting p53-PUMA mRNA expression by 5-flurouracil PLGA-lipid polymeric nanoparticles in mouse mammary carcinomas: comparison to free 5-flurouracil.

Polymeric poly (lactic-co-glycolic acid) (PLGA)-lipid hybrid nanoparticles (PNPs)-based therapy are powerful carriers for various therapeutic agents. This study was conducted to evaluate the chemotherapeutic potential of free 5-flurouracil (5FU) and synthetized 5FU-PNPs and impact on p53-dependent apoptosis in mammary carcinomas (MCs) grown in mice. Breast cancer cells were injected in Swiss albino female mice and 2 bilateral masses of MC were confirmed after one week. Mice were distributed to five experimental groups; Group 1: MC control group. Groups 2 and 3: MC + free 5FU [5 or 10 mg per kg] groups. Groups 4 and 5: synthetized MC+ 5FU-PNPs [5 or 10 mg per kg] groups. Medications were administered orally, twice weekly for 3 weeks. Then, tumors were dissected, and sections were stained with hematoxylin-eosin (HE) while the other MC was used for measuring of cell death and inflammatory markers. Treatment with 5FU-PNPs suppressed the MC masses and pathologic scores based on HE-staining. Similarly, greater proapoptotic activity was recorded in 5FU-PNPs groups compared to free 5FU groups as shown by significant upregulation in tumoral p53 immunostaining. The current results encourage the utility of PNPs for improving the antitumor effect of 5FU. The chemotherapeutic potential was mediated through enhancement of tumoral p53-mediated p53 up-regulated modulator of apoptosis (PUMA) genes. Additional studies are warranted for testing the antitumor activity of this preparation in other mouse models of breast cancer.

Multiple SNPs Downregulate Gene Expression of Matrix Metallopeptidase 2 in MCF7 Breast Cancer Cells

@#Introduction: On a global scale, breast cancer contributes the highest cancer-related deaths in women due to metastasis which renders the treatments ineffective and non-targeted. The members of Matrix Metallopeptidases, particularly Matrix Metallopeptidase 2 (MMP2), are among the key players in breast cancer metastasis. In most cases, MMP2 was markedly upregulated and linked to poor prognosis. In a previous study, in silico analyses revealed that several coding single nucleotide polymorphisms (SNPs) of MMP2 were shown to reduce gene expression and mRNA stability of MMP2 in Malaysian breast cancer patients. Therefore, to validate the in silico predictions, the objective of this study was to determine the effects of multiple coding SNPs of MMP2 on the gene expression and mRNA stability of MMP2 in breast cancer cells. Methods: In the current study, breast adenocarcinoma MCF7 cells were transfected with MMP2 wild type and variant containing the coding SNPs. After confirmation of transfection by DNA sequencing, the gene expression level of MMP2 was evaluated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) whereas mRNA stability of MMP2 was determined following treatment with actinomycin D. Results: MMP2 wild type and variant were successfully transfected in MCF7 cells based on sequencing and PCR analysis. It was found that the presence of coding SNPs lowered the gene expression level of MMP2, but not the stability of MMP2 mRNA. Conclusion: This study supports the in silico effects of MMP2 coding SNPs on its gene expression in an in vitro model.

Unveiling innovative therapeutic strategies and future trajectories on stimuli-responsive drug delivery systems for targeted treatment of breast carcinoma.

This comprehensive review delineates the latest advancements in stimuli-responsive drug delivery systems engineered for the targeted treatment of breast carcinoma. The manuscript commences by introducing mammary carcinoma and the current therapeutic methodologies, underscoring the urgency for innovative therapeutic strategies. Subsequently, it elucidates the logic behind the employment of stimuli-responsive drug delivery systems, which promise targeted drug administration and the minimization of adverse reactions. The review proffers an in-depth analysis of diverse types of stimuli-responsive systems, including thermoresponsive, pH-responsive, and enzyme-responsive nanocarriers. The paramount importance of material choice, biocompatibility, and drug loading strategies in the design of these systems is accentuated. The review explores characterization methodologies for stimuli-responsive nanocarriers and probes preclinical evaluations of their efficacy, toxicity, pharmacokinetics, and biodistribution in mammary carcinoma models. Clinical applications of stimuli-responsive systems, ongoing clinical trials, the potential of combination therapies, and the utility of multifunctional nanocarriers for the co-delivery of assorted drugs and therapies are also discussed. The manuscript addresses the persistent challenge of drug resistance in mammary carcinoma and the potential of stimuli-responsive systems in surmounting it. Regulatory and safety considerations, including FDA guidelines and biocompatibility assessments, are outlined. The review concludes by spotlighting future trajectories and emergent technologies in stimuli-responsive drug delivery, focusing on pioneering approaches, advancements in nanotechnology, and personalized medicine considerations. This review aims to serve as a valuable compendium for researchers and clinicians interested in the development of efficacious and safe stimuli-responsive drug delivery systems for the treatment of breast carcinoma.

Feline mammary carcinoma-derived extracellular vesicle promotes liver metastasis via sphingosine kinase-1-mediated premetastatic niche formation.

BACKGROUND: Feline mammary carcinoma (FMC) is one of the most prevalent malignancies of female cats. FMC is highly metastatic and thus leads to poor disease outcomes. Among all metastases, liver metastasis occurs in about 25% of FMC patients. However, the mechanism underlying hepatic metastasis of FMC remains largely uncharacterized. RESULTS: Herein, we demonstrate that FMC-derived extracellular vesicles (FMC-EVs) promotes the liver metastasis of FMC by activating hepatic stellate cells (HSCs) to prime a hepatic premetastatic niche (PMN). Moreover, we provide evidence that sphingosine kinase 1 (SK1) delivered by FMC-EV was pivotal for the activation of HSC and the formation of hepatic PMN. Depletion of SK1 impaired cargo sorting in FMC-EV and the EV-potentiated HSC activation, and abolished hepatic colonization of FMC cells. CONCLUSIONS: Taken together, our findings uncover a previously uncharacterized mechanism underlying liver-metastasis of FMC and provide new insights into prognosis and treatment of this feline malignancy.