Tumor microenvironment-mediated chemoresistance in breast cancer

Dickkopf-1 promotes tumor progression of gefitinib- resistant non-small cell lung cancer through cancer cell-fibroblast interactions

BACKGROUND

Cancer cell-secreted proteins play a critical role in tumor progression and chemoresistance by influencing intercellular interactions within the tumor microenvironment. Investigating the intratumoral functions of these secretory proteins may provide insights into understanding and treating chemoresistant cancers. This study aims to identify potential anticancer target(s) in gefitinib-resistant non-small cell lung cancer (NSCLC), with a focus on secretory proteins and their effects on intercellular interactions.

METHODS

Differentially expressed secretory proteins were identified in gefitinib-resistant human NSCLC cell lines (PC9-GR and HCC827-GR), revealing an elevation in Dickkopf-1 (DKK1) expression and secretion. To elucidate the role of DKK1 in gefitinib-resistant cancer, the anticancer effects of a neutralizing antibody against DKK1 were evaluated in tumors comprising either cancer cells alone or cancer cells co-injected with human lung fibroblasts (MRC-5). Following the confirmation of the importance of cancer cell-fibroblast interactions in the protumorigenic activity of DKK1, the fibroblast traits modulated by DKK1 were further analyzed.

RESULTS

Gefitinib-resistant NSCLC cells exhibited increased DKK1 protein expression. Although elevated DKK1 levels were linked to poor prognosis, DKK1 did not directly affect cancer cell proliferation. However, DKK1 blockade showed significant anticancer effects in gefitinib-resistant tumors containing lung fibroblasts, suggesting that DKK1's pro-tumorigenic roles are mediated through cancer cell-fibroblast interactions. DKK1 altered fibroblast characteristics, enhancing inflammatory fibroblast traits while diminishing myofibroblast traits in tumor microenvironment. These DKK1-induced changes were mediated via activation of the c-JUN pathway in fibroblasts. Moreover, DKK1 was identified as a potential anticancer target across various cancer types beyond gefitinib-resistant lung cancer.

CONCLUSIONS

This study clarifies that DKK1 mediates interactions between cancer cells and fibroblasts in gefitinib-resistant lung cancer, contributing to tumor progression. Therefore, we propose DKK1 as a promising anticancer target for the treatment of gefitinib-resistant NSCLC.

Pharmacological, computational, and mechanistic insights into triptolide's role in targeting drug-resistant cancers

As a promising candidate for tackling drug-resistant cancers, triptolide, a diterpenoid derived from the Chinese medicinal plant Tripterygium wilfordii, has been developed. This review summarizes potential antitumor activities, including the suppression of RNA polymerase II, the suppression of heat shock proteins (HSP70 and HSP90), and the blockade of NF-kB signalling. Triptolide is the first known compound to target cancer cells specifically but spare normal cells, and it has success in treating cancers that are difficult to treat, including pancreatic, breast, and lung cancers. It acts against the tolerance mechanisms, including efflux pump upregulation, epithelial-mesenchymal transition, and cancer stem cells. Triptolide modulates important cascades, including PI3K/AKT/mTOR, enhancing the efficacy of conventional therapies. Nonetheless, its clinical application is constrained by toxicity and bioavailability challenges. Emerging drug delivery systems, such as nanoparticles and micellar formulations, are being developed to address these limitations. It has strong interactions with key anticancer targets, like PARP, as determined in preclinical and computational studies consistent with its mechanism of action. Early-phase clinical trials of Minnelide, a water-soluble derivative of triptolide, are promising, but additional work is necessary to optimize dosing, delivery, and safety. This comprehensive analysis demonstrates that triptolide may constitute a repurposed precision medicine tool to overcome tolerance in cancer therapy.

Role of mast cell in locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy

The pro-tumor effects of mast cell (MC) in the tumor microenvironment (TME) are becoming increasingly clear. Recently, MC were shown to contribute to tumor malignancy by supporting the migration of tumor-associated macrophages (TAMs), suggesting a relationship with tumor immunity. In the current study, we aimed to examine the correlation between MC infiltration and neoadjuvant chemoradiotherapy (nCRT) response for locally advanced rectal cancer (LARC). Ninety-five LARC patients who recieved nCRT were enrolled in this study. Protein levels of the MC marker tryptase and TAM marker CD206 were evaluated with immunohistochemistry (IHC). The correlation between MC infiltration and prognostic factors was evaluated. The effects of MCs on the malignant potential were examined using in vitro proliferation and invasion assays with a colorectal cancer (CRC) cell line (HCT-116). Following nCRT, 31.6% of resected LARC patient specimens were positive for MC infiltration by tryptase IHC analysis. MC infiltration was significantly correlated with nCRT response. The 5-year disease-free survival (DFS) rate was significantly lower in the MC-positive group compared with the MC-negative group (52.3% vs. 76.8%). Univariate and multivariate analyses revealed that MC infiltration was the independent prognostic indicator for DFS. MC infiltration was significantly correlated with CD206 expression, and therefore TAMs. In vitro experiments suggested that tumor activated mast cells could promote CRC cell malignant behavior via production of macrophage inhibitory factor. MC infiltration in LARC patients was positively correlated with TAM infiltration and resistance to nCRT, and was also an independent poor prognostic indicator.

Circulating CD3+CD8+ T Lymphocytes as Indicators of Disease Status in Patients With Early Breast Cancer

Circulating CD3+CD8+ cell levels were lower in breast cancer patients, elevated posttreatment, and subsequently declining upon recurrence. Elevated plasma chemokine (C-C motif) ligand 2 (CCL2) levels distinguished patients with breast cancer from healthy controls. In summary, circulating CD3+CD8+ CTL and plasma CCL2 levels emerged as promising dual-purpose biomarkers and therapeutic targets in breast cancer management.

In vitro treatment of triple-negative breast cancer cells with an extract from the Coriolus versicolor mushroom changes macrophage properties related to tumourigenesis

Macrophages, the most abundant cells that participate in tumour progression, are the subject of a number of anticancer therapy approaches. Our previous results revealed that an extract of the fungus Coriolus versicolor (CV) has anti-cancer and immunomodulatory properties. The aim of the present study was to investigate whether CV extract-treated triple-negative breast cancer (TNBC) cells can release factors that can reprogram macrophages from pro-tumourigenic to anti-cancer subtypes. RAW 264.7 macrophages were cultured in a conditioned medium (CM) from non-treated 4T1 breast cancer cells (CM-NT) or CV extract-stimulated cells (CM-CV). After treatment, the following macrophage properties were evaluated: cell viability; M1/M2 phenotype (enzyme activities: iNOS and arginase 1; and expression of CD molecules: CD80 and CD163); cytokine concentrations: IL-6, TNF-α, IL-10, TGF-β, MCP-1 and VEGF; migration level; and ROS production. The results revealed that, compared with normal cells, TNBC cells stimulated with CV extract create a microenvironment that promotes a decrease in macrophage viability and migration, intracellular ROS production, and pro-angiogenic cytokine production (VEGF and MCP-1). Moreover, CM-CV decreased the expression of M2 macrophage markers (arginase 1 and CD163; IL-10 and TGF-β) but upregulated the expression of M1 cell markers (iNOS and CD80; IL-6 and TNF-α). We concluded that CV extract modifies the tumour microenvironment and changes macrophage polarisation toward functioning as an anti-tumour agent. Therefore, it is promising to use in the treatment of TNBC-associated macrophages.

Molecular mechanism of PARP inhibitor resistance

Poly (ADP-ribose) polymerases (PARP) inhibitors (PARPi) are the first-approved anticancer drug designed to exploit synthetic lethality. PARPi selectively kill cancer cells with homologous recombination repair deficiency (HRD), as a result, PARPi are widely employed to treated BRCA1/2-mutant ovarian, breast, pancreatic and prostate cancers. Currently, four PARPi including Olaparib, Rucaparib, Niraparib, and Talazoparib have been developed and greatly improved clinical outcomes in cancer patients. However, accumulating evidences suggest that required or de novo resistance emerged. In this review, we discuss the molecular mechanisms leading to PARPi resistances and review the potential strategies to overcome PARPi resistance.

Induced expression of AMOT reverses adriamycin resistance in breast cancer cells

Adriamycin (ADR) is widely used against breast cancer, but subsequent resistance always occurs. YAP, a downstream protein of angiomotin (AMOT), importantly contributes to ADR resistance, whereas the mechanism is largely unknown. MCF-7 cells and MDA-MB-231 cells were used to establish ADR-resistant cell. Then, mRNA and protein expressions of AMOT and YAP expressions were determined. After AMOT transfection alone or in combination with YAP, the sensitivity of the cells to ADR were evaluated in vitro by examining cell proliferation, apoptosis, and cell cycle, as well as in vivo by examining tumor growth. Additionally, the expressions of proteins in YAP pathway were determined in AMOT-overexpressing cells. In the ADR-resistant cells, the expression of AMOT was decreased while YAP was increased, respectively, and the nucleus localization of YAP was increased at the same time. After AMOT overexpression, these were inhibited, whereas the cell sensitivity to ADR was enhanced. However, the AMOT-induced changes were significantly suppressed by YAP knockdown. The consistent results in vivo showed that AMOT enhanced the inhibition of ADR on tumor growth, and inhibited YAP signaling, evidenced by decreased levels of YAP, CycD1, and p-ERK. Our data revealed that decreased AMOT contributed to ADR resistance in breast cancer cells, which was importantly negatively mediated YAP. These observations provide a potential therapy against breast cancer with ADR resistance.

Tumor microenvironment: A playground for cells from multiple diverse origins

Tumor microenvironment is formed by various cellular and non-cellular components which interact with one another and form a complex network of interactions. Some of these cellular components also attain a secretory phenotype and release growth factors, cytokines, chemokines etc. in the surroundings which are capable of inducing even greater number of signalling networks. All these interactions play a decisive role in determining the course of tumorigenesis. The treatment strategies against cancer also exert their impact on the local microenvironment. Such interactions and anticancer therapies have been found to induce more deleterious outcomes like immunosuppression and chemoresistance in the process of tumor progression. Hence, understanding the tumor microenvironment is crucial for dealing with cancer and chemoresistance. This review is an attempt to develop some understanding about the tumor microenvironment and different factors which modulate it, thereby contributing to tumorigenesis. Along with summarising the major components of tumor microenvironment and various interactions taking place between them, it also throws some light on how the existing and potential therapies exert their impact on these dynamics.

Analyses of hypoxia-related risk factors and clinical relevance in breast cancer

Introduction

Hypoxia plays an important role in the heterogeneity, relapse, metastasis, and drug resistance of breast cancer. In this study, we explored the hypoxia-related biological signatures in different subtypes of breast cancer and identified the key prognostic factors by bioinformatics methods.

Methods

Based on The Cancer Genome Atlas (TCGA) Breast Cancer datasets, we divided the samples into immune-activated/suppressed populations by single-sample gene set enrichment analysis (ssGSEA) and then used hierarchical clustering to further identify hypoxic/non-hypoxic populations from the immune-suppressed samples. A hypoxia related risk model of breast cancer was constructed.

Results

Nuclear factor interleukin-3 regulated (NFIL3), serpin family E member 1 (SERPINE1), FOS, biglycan (BGN), epidermal growth factor receptor (EGFR), and sushi-repeat-containing protein, X-linked (SRPX) were identified as key hypoxia-related genes. Margin status, American Joint Committee on Cancer (AJCC) stage, hypoxia status, estrogen receptor/progesterone receptor (ER/PR) status, NFIL3, SERPINE1, EGFR, and risk score were identified as independent prognostic indicators for breast cancer patients. The 3- and 5-year survival curves of the model and immunohistochemical staining on the breast cancer microarray verified the statistical significance and feasibility of our model. Among the different molecular types of breast cancer, ER/PR+ and HER2+ patients might have higher hypoxia-related risk scores. ER/PR-negative samples demonstrated more activated immune-related pathways and better response to most anticancer agents.

Discussion

Our study revealed a novel risk model and potential feasible prognostic factors for breast cancer and might provide new perspectives for individual breast cancer treatment.

Cell plasticity modulation by flavonoids in resistant breast carcinoma targeting the nuclear factor kappa B signaling

Cancer cell plasticity plays a crucial role in tumor initiation, progression, and metastasis and is implicated in the multiple cancer defense mechanisms associated with therapy resistance and therapy evasion. Cancer resistance represents one of the significant obstacles in the clinical management of cancer. Some reversal chemosensitizing agents have been developed to resolve this serious clinical problem, but they have not yet been proven applicable in oncological practice. Activated nuclear factor kappa B (NF-κB) is a frequently observed biomarker in chemoresistant breast cancer (BC). Therefore, it denotes an attractive cellular target to mitigate cancer resistance. We summarize that flavonoids represent an essential class of phytochemicals that act as significant regulators of NF-κB signaling and negatively affect the fundamental cellular processes contributing to acquired cell plasticity and drug resistance. In this regard, flavokawain A, icariin, alpinetin, genistein, wogonin, apigenin, oroxylin A, xanthohumol, EGCG, hesperidin, naringenin, orientin, luteolin, delphinidin, fisetin, norwogonin, curcumin, cardamonin, methyl gallate and catechin-3-O-gallate, ampelopsin, puerarin, hyperoside, baicalein, paratocarpin E, and kaempferol and also synthetic flavonoids such as LFG-500 and 5,3'-dihydroxy-3,6,7,8,4'-pentamethoxyflavone have been reported to specifically interfere with the NF-κB pathway with complex signaling consequences in BC cells and could be potentially crucial in re-sensitizing unresponsive BC cases. The targeting NF-κB by above-mentioned flavonoids includes the modification of tumor microenvironment and epithelial-mesenchymal transition, growth factor receptor regulations, and modulations of specific pathways such as PI3K/AKT, MAP kinase/ERK, and Janus kinase/signal transduction in BC cells. Besides that, NF-κB signaling in BC cells modulated by flavonoids has also involved the regulation of ATP-binding cassette transporters, apoptosis, autophagy, cell cycle, and changes in the activity of cancer stem cells, oncogenes, or controlling of gene repair. The evaluation of conventional therapies in combination with plasticity-regulating/sensitizing agents offers new opportunities to make significant progress towards a complete cure for cancer.

Stroma modulation of radiation response in head and neck squamous cell carcinoma: Insights from zebrafish larvae xenografts

BACKGROUND

The tumour microenvironment (TME) of head and neck squamous cell carcinoma (HNSCC) consists of different subtypes of cells that interact with the tumour or with each other. This study investigates the possibility of co-culturing HNSCC cells with different stroma cells in a zebrafish xenograft model, focusing on the effect of stroma cells on HNSCC growth and response to irradiation.

MATERIAL AND METHOD

HNSCC metastatic cell line HSC-3 was used along with five types of stroma cells: normal gingival fibroblasts (NOF), cancer associated fibroblasts (CAF), macrophages, CD4+ T cells, and human umbilical vein endothelial cells (HUVEC). The mixture of HSC-3 cells and each-stroma cell type-was injected into 2-day post-fertilization zebrafish embryos, and the effect of stroma cells on tumour growth was tested. The study also aimed to mimic the HNSCC tumour by injecting a mixture of HSC-3 cells, CAFs, macrophages, and HUVECs into zebrafish embryos and testing the effect of these stroma cells on the cancer cells' response to irradiation compared to HSC-3-only tumours.

RESULTS

CAFs had a significant inducement effect on tumour size, while HUVECs showed the opposite effect. The irradiated group of HSC-3-only tumour had a significantly smaller tumor cell area compared to the control, while the group with stroma cells and HSC-3 cells showed cancer cells being resistant to irradiation.

CONCLUSION

This is the first report of co-culturing cancer cells with several types of stroma cells using a zebrafish xenograft model. This study also highlighted the role of stroma cells in turning the cancer cells from radioresponsive to radioresistant.

Non-Coding RNAs and the Development of Chemoresistance to Docetaxel in Prostate Cancer: Regulatory Interactions and Approaches Based on Machine Learning Methods

Chemotherapy based on taxane-class drugs is the gold standard for treating advanced stages of various oncological diseases. However, despite the favorable response trends, most patients eventually develop resistance to this therapy. Drug resistance is the result of a combination of different events in the tumor cells under the influence of the drug, a comprehensive understanding of which has yet to be determined. In this review, we examine the role of the major classes of non-coding RNAs in the development of chemoresistance in the case of prostate cancer, one of the most common and socially significant types of cancer in men worldwide. We will focus on recent findings from experimental studies regarding the prognostic potential of the identified non-coding RNAs. Additionally, we will explore novel approaches based on machine learning to study these regulatory molecules, including their role in the development of drug resistance.

Periostin facilitates ovarian cancer recurrence by enhancing cancer stemness

The lethality of epithelial ovarian cancer (OC) is largely due to a high rate of recurrence and development of chemoresistance, which requires synergy between cancer cells and the tumor microenvironment (TME) and is thought to involve cancer stem cells. Our analysis of gene expression microarray data from paired primary and recurrent OC tissues revealed significantly elevated expression of the gene encoding periostin (POSTN) in recurrent OC compared to matched primary tumors (p = 0.015). Secreted POSTN plays a role in the extracellular matrix, facilitating epithelial cell migration and tissue regeneration. We therefore examined how elevated extracellular POSTN, as we found is present in recurrent OC, impacts OC cell functions and phenotypes, including stemness. OC cells cultured with conditioned media with high levels of periostin (CMPOSTNhigh) exhibited faster migration (p = 0.0044), enhanced invasiveness (p = 0.006), increased chemoresistance (p < 0.05), and decreased apoptosis as compared to the same cells cultured with control medium (CMCTL). Further, CMPOSTNhigh-cultured OC cells exhibited an elevated stem cell side population (p = 0.027) along with increased expression of cancer stem cell marker CD133 relative to CMCTL-cultured cells. POSTN-transfected 3T3-L1 cells that were used to generate CMPOSTNhigh had visibly enhanced intracellular and extracellular lipids, which was also linked to increased OC cell expression of fatty acid synthetase (FASN) that functions as a central regulator of lipid metabolism and plays a critical role in the growth and survival of tumors. Additionally, POSTN functions in the TME were linked to AKT pathway activities. The mean tumor volume in mice injected with CMPOSTNhigh-cultured OC cells was larger than that in mice injected with CMCTL-cultured OC cells (p = 0.0023). Taken together, these results show that elevated POSTN in the extracellular environment leads to more aggressive OC cell behavior and an increase in cancer stemness, suggesting that increased levels of stromal POSTN during OC recurrence contribute to more rapid disease progression and may be a novel therapeutic target. Furthermore, they also demonstrate the utility of having matched primary-recurrent OC tissues for analysis and support the need for better understanding of the molecular changes that occur with OC recurrence to develop ways to undermine those processes.

Development of a Machine Learning-Based Prognostic Model for Hormone Receptor-Positive Breast Cancer Using Nine-Gene Expression Signature

Background

Determining the prognosis of hormone receptor positive (HR+) breast cancer (BC), which accounts for 80% of all BCs, is critical in improving survival outcomes. Stratifying individuals at high risk of BC-related mortality and improving prognosis has been the focus of research for over a decade. However, these tools are not universal as they are limited to clinical factors. We hypothesized that a new framework for predicting prognosis in HR+ BC patients can develop using artificial intelligence.

Methods

A total of 2,338 HR+ human epidermal growth factor receptor 2 negative (HER2-) BC cases were analyzed from Molecular Taxonomy of Breast Cancer International Consortium (METABRIC), The Cancer Genome Atlas (TCGA), and Gene Expression Omnibus (GEO) cohorts. Groups were then divided into high- and low-risk categories utilizing a recurrence prediction model (RPM). An RPM was created by extracting nine prognosis-related genes from over 18,000 genes using a logistic progression model.

Results

Risk classification by RPM was significantly stratified in both the discovery cohort and validation cohort. In the time-dependent area under the curve analysis, there was some variation depending on the cohort, but accuracy was found to decline significantly after about 10 years. Cell cycle related gene sets, MYC, and PI3K-AKT-mTOR signaling were enriched in high-risk tumors by the Gene Set Enrichment Analysis. High-risk tumors were associated with high levels of immune cells from the lymphoid and myeloid lineage and immune cytolytic activity, as well as low levels of stem cells and stromal cells. High-risk tumors were also associated with poor therapeutic effects of chemotherapy and endocrine therapy.

Conclusions

This model was able to stratify prognosis in multiple cohorts. This is because the model reflects major BC therapeutic target pathways and tumor immune microenvironment and, further is supported by the therapeutic effect of chemotherapy and endocrine therapy.

Mesenchymal stromal cells confer breast cancer doxorubicin resistance by producing hyaluronan

Chemotherapy resistance represents a major cause of therapeutic failure and mortality in cancer patients. Mesenchymal stromal cells (MSCs), an integral component of tumor microenvironment, are known to promote drug resistance. However, the detailed mechanisms remain to be elucidated. Here, we found that MSCs confer breast cancer resistance to doxorubicin by diminishing its intratumoral accumulation. Hyaluronan (HA), a major extracellular matrix (ECM) product of MSCs, was found to mediate the chemoresistant effect. The chemoresistant effect of MSCs was abrogated when hyaluronic acid synthase 2 (HAS2) was depleted or inhibited. Exogenous HA also protected tumor grafts from doxorubicin. Molecular dynamics simulation analysis indicates that HA can bind with doxorubicin, mainly via hydrophobic and hydrogen bonds, and thus reduce its entry into breast cancer cells. This mechanism is distinct from the reported chemoresistant effect of HA via its receptor on cell surface. High HA serum levels were also found to be positively associated with chemoresistance in breast cancer patients. Our findings indicate that the HA-doxorubicin binding dynamics can confer cancer cells chemoresistance. Reducing HA may enhance chemotherapy efficacy.

A hybrid breast cancer/mesenchymal stem cell population enhances chemoresistance and metastasis

Patients with triple-negative breast cancer remain at risk for metastatic disease despite treatment. The acquisition of chemoresistance is a major cause of tumor relapse and death, but the mechanisms are far from understood. We have demonstrated that breast cancer cells (BCCs) can engulf mesenchymal stem/stromal cells (MSCs), leading to enhanced dissemination. Here, we show that clinical samples of primary invasive carcinoma and chemoresistant breast cancer metastasis contain a unique hybrid cancer cell population coexpressing pancytokeratin and the MSC marker fibroblast activation protein-α. We show that hybrid cells form in primary tumors and that they promote breast cancer metastasis and chemoresistance. Using single-cell microfluidics and in vivo models, we found that there are polyploid senescent cells within the hybrid cell population that contribute to metastatic dissemination. Our data reveal that Wnt Family Member 5A (WNT5A) plays a crucial role in supporting the chemoresistance properties of hybrid cells. Furthermore, we identified that WNT5A mediates hybrid cell formation through a phagocytosis-like mechanism that requires BCC-derived IL-6 and MSC-derived C-C Motif Chemokine Ligand 2. These findings reveal hybrid cell formation as a mechanism of chemoresistance and suggest that interrupting this mechanism may be a strategy in overcoming breast cancer drug resistance.

Biological differences between normal and cancer-associated fibroblasts in breast cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) constitute the primary constituents of the tumor microenvironment (TME) and exert significant influences on cancer progression. However, adequate comprehension of CAF profiles in breast cancer, as well as the precise mechanisms underlying their promotion of cancer, remains lacking.

OBJECTIVES

To discerns the biological differences between normal fibroblasts (NFs) and CAFs in breast cancer and explore the underlying mechanism.

METHODS

Three pairs of CAFs and NFs were isolated from breast cancer patients of diverse subtypes who had not undergone prior radiotherapy or chemotherapy. Morphological characteristics of CAFs and NFs were assessed through optical and electron microscopy, their biological attributes were examined using cell counting kits and transwell assays, and their impact on breast cancer cells was simulated using a coculture system. Furthermore, the miRNA profiles of CAFs and NFs were sequenced via an Illumina HiSeq 2500 platform.

RESULTS

CAFs exhibited higher growth rate and motility than NFs and a stronger potential to promote the malignancy of breast cancer cells. RNA sequencing of both NFs and CAFs revealed differentially expressed miRNAs with notable variability among distinct patients within their NFs and CAFs, while the enrichment of the target genes of differentially expressed miRNAs within both GO terms and KEGG pathways demonstrated significant similarity across patients with different profiles.

CONCLUSION

CAFs have greater malignancy and higher potential to influence the growth, migration, invasion and chemoresistance of cocultured breast cancer cells than NFs. In addition, the miRNAs that are differentially expressed in CAFs when compared to NFs display substantial variability across patients with distinct breast cancer subtypes, while the enrichment of target genes regulated by these miRNAs, within GO terms and KEGG pathways, remains remarkably consistent among patients with varying profiles.

Capecitabine Plus Aromatase Inhibitor as First Line Therapy for Hormone Receptor Positive, HER2 Negative Metastatic Breast Cancer

(1) Background: recent evidence suggests that long low-dose capecitabine regimens have a synergistic effect with endocrine therapy as aromatase inhibitors (AIs), and might increase overall survival for hormone-receptor-positive, HER2-negative, metastatic breast cancer compared to both treatments. We performed a retrospective study to confirm the efficacy and expand the safety data for capecitabine plus AI (a combination henceforth named XELIA) for this indication. (2) We conducted a single-center retrospective cohort study of 163 hormone receptor-positive metastatic breast cancer patients who received either the XELIA regimen, capecitabine, or an aromatase inhibitor (AI) as single agents in first-line treatment. The primary endpoint was progression-free survival, and the secondary endpoints were overall survival, best objective response, and toxicity incidence. (3) Results: the median progression-free survival for patients receiving XELIA, AI, and capecitabine was 29.37 months (20.91 to 37.84; 95% CI), 20.04 months (7.29 to 32.80; 95% CI) and 10.48 (8.69 to 12.28; 95% CI), respectively. The overall response rate was higher in the XELIA group (29.5%) than in the AI (14.3%) and capecitabine (9.1%) groups. However, the differences in overall survival were not statistically significant. Apart from hand-foot syndrome, there were no statistically significant differences in adverse events between the groups. (4) Conclusions: this retrospective study suggests that progression-free survival and overall response rates improved with the XELIA regimen compared to use of aromatase inhibitors and capecitabine alone. Combined use demonstrated an adequate safety profile and might represent an advantageous treatment in places where CDK 4/6 is not available. Larger studies and randomized clinical trials are required to confirm the effects shown in our study.

Cancer Antigen 125 Expression Enhances the Gemcitabine/Cisplatin-Resistant Tumor Microenvironment in Bladder Cancer

Cancer antigen 125 (CA125) is one of the mucin family proteins and is a serum tumor marker for various tumors, such as ovarian cancer, endometrial cancer, pancreatic cancer, and bladder cancer. CA125 is used to distinguish between benign and malignant tumors, monitor the response to chemotherapy, and detect relapse after initial treatment. Recently, CA125 was reported to be involved in chemoresistance through the physical characteristics of mucin or by modifying the immune tumor-microenvironment. However, the relationship between CA125 expression and chemoresistance in bladder cancer is still unclear. In this study, the clinicopathologic features of bladder cancer with CA125 expression and the status of the tumor-microenvironment related to gemcitabine/cisplatin resistance were investigated using publicly available data sets (Cancer Genome Atlas Expression, GSE169455 data set) from the cBioPortal website, the National Center for Biotechnology Information website, and an in-house case collection of bladder cancer. The cases with CA125 expression had poorer disease-free and overall survival rates than those without CA125 expression. A mucinous area surrounding cancer cells was frequently detected in cases with CA125 expression (81%; 13/16 cases). CA125 expression was also related to the immunosuppressive tumor-microenvironment through the infiltration of immunosuppressive immune cells, such as regulatory T cells and M2 macrophages. These results suggest that the status of tumor-microenvironment associated with CA125 is involved in gemcitabine/cisplatin resistance in bladder cancer.

Seed-derived peptide lunasin suppressed breast cancer cell growth by regulating inflammatory mediators, aromatase, and estrogen receptors

Background

Breast cancer is one of the most prevalent cancers in women. Its pathology comprises tumor cells and nearby stromal cells, accompanied by cytokines and stimulated molecules, resulting in a favorable microenvironment for tumor progression. Lunasin is a seed peptide with multiple bioactivities derived from seeds. However, the chemopreventive effect of lunasin on different characteristics of breast cancer has not been fully explored.

Objective

This study aims to explore the chemopreventive mechanisms of lunasin through inflammatory mediators and estrogen-related molecules in breast cancer cells.

Design

Estrogen-dependent MCF-7 and independent MDA-MB-231 breast cancer cells were used. The β-estradiol was used to mimic physiological estrogen. The gene expression, mediator secretion, cell vitality, and apoptosis impacting breast malignancy were explored.

Results

Lunasin did not affect normal MCF-10A cell growth but inhibited breast cancer cell growth, increased interleukin (IL)-6 gene expression and protein production at 24 h, and decreased its secretion at 48 h. In both breast cancer cells, aromatase gene and activity and estrogen receptor (ER)α gene expression were decreased by lunasin treatment, while ERβ gene levels were significantly increased in MDA-MB-231 cells. Moreover, lunasin decreased vascular endothelial growth factor (VEGF) secretion and cell vitality and induced cell apoptosis in both breast cancer cell lines. However, lunasin only decreased leptin receptor (Ob-R) mRNA expression in MCF-7 cells. Additionally, β-estradiol increased MCF-7-cell proliferation but not the proliferation of other cells; in particular, lunasin still inhibited MCF-7-cell growth and cell vitality in the presence of β-estradiol.

Conclusion

Seed peptide lunasin inhibited breast cancer cell growth by regulating inflammatory, angiogenic, and estrogen-related molecules, suggesting that lunasin is a promising chemopreventive agent.

Insights into stimuli-responsive diselenide bonds utilized in drug delivery systems for cancer therapy

Due to the complexity and particularity of cancer cell microenvironments, redox responsive drug delivery systems (DDSs) for cancer therapy have been extensively explored. Compared with widely reported cancer treatment systems based on disulfide bonds, diselenide bonds have better redox properties and greater anticancer efficiency. In this review, the significance and application of diselenide bonds in DDSs are summarized, and the stimulation sensitivity of diselenide bonds is comprehensively reported. The potential and prospects for the application of diselenide bonds in next-generation anticancer drug treatment systems are extensively discussed.

A tumor microenvironment-related risk model for predicting the prognosis and tumor immunity of breast cancer patients

Background

This study aimed to construct a tumor microenvironment (TME)-related risk model to predict the overall survival (OS) of patients with breast cancer.

Methods

Gene expression data from The Cancer Genome Atlas was used as the training set. Differentially expressed gene analysis, prognosis analysis, weighted gene co-expression network analysis, Least Absolute Shrinkage and Selection Operator regression analysis, and Wald stepwise Cox regression were performed to screen for the TME-related risk model. Three Gene Expression Omnibus databases were used to validate the predictive efficiency of the prognostic model. The TME-risk-related biological function was investigated using the gene set enrichment analysis (GSEA) method. Tumor immune and mutation signatures were analyzed between low- and high-TME-risk groups. The patients’ response to chemotherapy and immunotherapy were evaluated by the tumor immune dysfunction and exclusion (TIDE) score and immunophenscore (IPS).

Results

Five TME-related genes were screened for constructing a prognostic signature. Higher TME risk scores were significantly associated with worse clinical outcomes in the training set and the validation set. Correlation and stratification analyses also confirmed the predictive efficiency of the TME risk model in different subtypes and stages of breast cancer. Furthermore, immune checkpoint expression and immune cell infiltration were found to be upregulated in the low-TME-risk group. Biological processes related to immune response functions were proved to be enriched in the low-TME-risk group through GSEA analysis. Tumor mutation analysis and TIDE and IPS analyses showed that the high-TME-risk group had more tumor mutation burden and responded better to immunotherapy.

Conclusion

The novel and robust TME-related risk model had a strong implication for breast cancer patients in OS, immune response, and therapeutic efficiency.

Systematic analyses to explore immune gene sets-based signature in hepatocellular carcinoma, in which IGF2BP3 contributes to tumor progression

Tumor immune microenvironment (TIME) is of critical importance for the development and therapeutic response of hepatocellular carcinoma (HCC). However, limited studies have investigated immune-related indicators for clinical supervision and decision. The current study aimed to develop an improved prognostic signature based on TIME. HCC patients from TCGA and ICGC database were classified into three subtypes (Immunity High, Immunity Medium and Immunity Low) according to ssGSEA scores of 29 immune gene sets. Differentially expressed immune-related genes (DE IRGs) between Immune High and Low groups were screened with an adjusted P < 0.05. Weighted gene co-expression network analysis (WGCNA) was used to establish gene co-expression modules of differentially expressed genes (DEGs) between tumor and normal tissues. 45 survival-related immune genes (SRIGs) were identified at points of intersection between hub genes and DE IRGs. By performing Cox regression and LASSO analysis, 3 of the 45 SRIGs were screened to establish a prognostic model. Patients with high risk scores exhibited worse survival outcome and poorer response to chemotherapy. Potential mechanisms of chemotherapy resistance also have been discussed. More significantly, high -risk patients showed increased immune cell infiltration and checkpoints, which suggested a benefit of immunotherapy. In addition, knockdown of IGF2BP3 was determined to significantly inhibit cell proliferation and migration in HCC. Our immune-related model may be an effective tool for precise diagnosis and treatment of HCC. It may help to select patients suitable for chemotherapy, and immunotherapy.

Clinical Relevance of Estrogen Reactivity in the Breast Cancer Microenvironment

Purpose

Estrogen signals play an important role in the phenotype of estrogen receptor-positive breast cancer. However, comprehensive analyses of the effect of responsiveness to estrogen signals on the tumor microenvironment and survival in large cohorts of primary breast cancer patients have been lacking. We aimed to test the hypothesis that estrogen reactivity affects gene expression and immune cell infiltration profiles in the tumor microenvironment and survival.

Methods

A total of 3,098 breast cancer cases were analyzed: 1,904 from the Molecular Taxonomy of Breast Cancer (METABRIC) cohort, 1,082 from The Cancer Genome Atlas (TCGA) cohort, and 112 from the Hokkaido University Hospital cohort. We divided the group into estrogen reactivity-high and estrogen reactivity-low groups utilizing the scores of ESTROGEN_RESPONSE_EARLY and ESTROGEN_RESPONSE_LATE in Gene Set Variation Analysis.

Results

Breast cancer with high estrogen reactivity was related to Myc targets, metabolism-related signaling, cell stress response, TGF-beta signaling, androgen response, and MTORC1 signaling gene sets in the tumor microenvironment. Low estrogen reactivity was related to immune-related proteins, IL2-STAT5 signaling, IL6-JAK-STAT3 signaling, KRAS signaling, cell cycle-related gene sets, and EMT. In addition, breast cancer with high levels of estrogen reactivity had low immune cytolytic activity and low levels of immunostimulatory cells. It also had low levels of stimulatory and inhibitory factors of the cancer immunity cycle. Patients with high estrogen reactivity were also associated with a better prognosis.

Conclusion

We demonstrated the relationship between estrogen reactivity and the profiles of immune cells and gene expression, as well as survival.

Amlodipine inhibits proliferation, invasion, and colony formation of breast cancer cells

Calcium channel upregulation has been implicated in cancer cell proliferation and progression including in breast cancer. Fortunately, the function of calcium channels can be manipulated pharmacologically using calcium channel blockers (CCBs). Amlodipine, a dihydropyridine CCB, has been demonstrated to exert cytotoxic effects in several types of cancers. The present study evaluated the effects of amlodipine on proliferation, caspase activation, colony formation, and invasion of human breast cancer cells. Cell viability was assessed using a colorimetric MTT assay. An Apo-ONE® caspase-3/7 assay was used to measure caspase-3/7 levels. Cell invasion was evaluated using Matrigel invasion chambers. The expression of phospho-(p-)ERK1/2, Bcl-2, and integrin β1 proteins were analyzed using western blotting. A one-way ANOVA with a post-hoc Tukey's multiple comparison tests was used for statistical analysis. Amlodipine significantly inhibited the growth of both MDA-MB-231 and MCF-7 human breast cancer cells in a dose-dependent manner and inhibited colony formation of MCF-7 cells, and this was accompanied by the downregulation of p-ERK1/2 in MDA-MB-231 cells. In addition, treatment with amlodipine resulted in increased caspase-3/7 levels in MDA-MB-231 cells, which was accompanied by the downregulation of the anti-apoptotic protein, Bcl-2. Moreover, amlodipine impaired the invasive abilities of MDA-MB-231 cells, and integrin β1 expression was concurrently downregulated. The present study illustrates the anticancer effects of amlodipine on breast cancer proliferation, colony formation, and invasion in vitro and highlights the potential value of amlodipine as an anticancer agent.

Direct Cell-Cell Communication via Membrane Pores, Gap Junction Channels, and Tunneling Nanotubes: Medical Relevance of Mitochondrial Exchange

The history of direct cell-cell communication has evolved in several small steps. First discovered in the 1930s in invertebrate nervous systems, it was thought at first to be an exception to the "cell theory", restricted to invertebrates. Surprisingly, however, in the 1950s, electrical cell-cell communication was also reported in vertebrates. Once more, it was thought to be an exception restricted to excitable cells. In contrast, in the mid-1960s, two startling publications proved that virtually all cells freely exchange small neutral and charged molecules. Soon after, cell-cell communication by gap junction channels was reported. While gap junctions are the major means of cell-cell communication, in the early 1980s, evidence surfaced that some cells might also communicate via membrane pores. Questions were raised about the possible artifactual nature of the pores. However, early in this century, we learned that communication via membrane pores exists and plays a major role in medicine, as the structures involved, "tunneling nanotubes", can rescue diseased cells by directly transferring healthy mitochondria into compromised cells and tissues. On the other hand, pathogens/cancer could also use these communication systems to amplify pathogenesis. Here, we describe the evolution of the discovery of these new communication systems and the potential therapeutic impact on several uncurable diseases.

Overexpression of microRNA-145 enhanced docetaxel sensitivity in breast cancer cells via inactivation of protein kinase B gamma-mediated phosphoinositide 3-kinase -protein kinase B pathway

Chemoresistance is a major challenge for the treatment of breast cancer (BC). Previous studies showed that miR-145 level decreases in chemoresistant BC tissues. Nevertheless, the biological function of miR-145 on docetaxel resistance of BC cells remains unclear, which is what our research attempted to clarify. RT-qPCR analyzed miR-145 level, and cell viability and colony formation assays assessed the impact of miR-145 on docetaxel resistance. Molecular mechanisms of miR-145-mediated docetaxel sensitivity were examined by Luciferase reporter assay and Western Blot assessed the function of AKT3 and PI3K/AKT signaling. Our research found that miR-145 expression presented significant downregulation in docetaxel-resistant BC cells. Meanwhile, miR-145 overexpression facilitated the docetaxel sensitivity of BC cells in vivo and in vitro, while the miR-145 inhibitor decreased the sensitivity of BC cells to docetaxel. We also observed that miR-145 inhibited docetaxel resistance mainly via downregulation of the AKT3 expression and further inhibited PI3K/AKT pathway. To conclude, this research provides a novel strategy for improving chemosensitivity through the newly identified miR-145-AKT3/PI3K-AKT signaling pathway in BC.

Prognostic significance of Naples prognostic score in non-small-cell lung cancer patients with brain metastases

Aims: The authors aimed to evaluate the prognostic value of Naples prognostic score (NPS) in advanced non-small-cell lung cancer patients with brain metastases. Materials & methods: A total of 186 consecutive advanced non-small-cell lung cancer patients were retrospectively analyzed. Kaplan-Meier survival analysis and Cox proportional regression models were used to assess the significance of NPS in overall survival and disease-free survival. Results: Multivariate Cox proportional regression analysis revealed that NPS was a significant independent predictive indicator for overall survival (hazard ratio: 1.897; 95% CI: 1.184-3.041; p = 0.008) and disease-free survival (hazard ratio: 2.169; 95% CI: 1.367-3.44; p = 0.001). Conclusion: NPS was a powerful prognostic indicator for outcome in advanced non-small-cell lung cancer patients with brain metastases.

Extracellular Vesicles as Mediators of Therapy Resistance in the Breast Cancer Microenvironment

Resistance to various therapies, including novel immunotherapies, poses a major challenge in the management of breast cancer and is the leading cause of treatment failure. Bidirectional communication between breast cancer cells and the tumour microenvironment is now known to be an important contributor to therapy resistance. Several studies have demonstrated that crosstalk with the tumour microenvironment through extracellular vesicles is an important mechanism employed by cancer cells that leads to drug resistance via changes in protein, lipid and nucleic acid cargoes. Moreover, the cargo content enables extracellular vesicles to be used as effective biomarkers for predicting response to treatments and as potential therapeutic targets. This review summarises the literature to date regarding the role of extracellular vesicles in promoting therapy resistance in breast cancer through communication with the tumour microenvironment.

Integrated Analysis to Obtain Potential Prognostic Signature in Glioblastoma

Glioblastoma multiforme (GBM) is the most malignant and multiple tumors of the central nervous system. The survival rate for GBM patients is less than 15 months. We aimed to uncover the potential mechanism of GBM in tumor microenvironment and provide several candidate biomarkers for GBM prognosis. In this study, ESTIMATE analysis was used to divide the GBM patients into high and low immune or stromal score groups. Microenvironment associated genes were filtered through differential analysis. Weighted gene co-expression network analysis (WGCNA) was performed to correlate the genes and clinical traits. The candidate genes’ functions were annotated by enrichment analyses. The potential prognostic biomarkers were assessed by survival analysis. We obtained 81 immune associated differentially expressed genes (DEGs) for subsequent WGCNA analysis. Ten out of these DEGs were significantly associated with targeted molecular therapy of GBM patients. Three genes (S100A4, FCGR2B, and BIRC3) out of these genes were associated with overall survival and the independent test set testified the result. Here, we obtained three crucial genes that had good prognostic efficacy of GBM and may help to improve the prognostic prediction of GBM.

Resveratrol enhanced chemosensitivity by reversing macrophage polarization in breast cancer

BACKGROUND

Resveratrol, a naturally occurring polyphenolic compound, has been shown to inhibit cancer growth by targeting several cancer-related signalling pathways. In the tumor microenvironment (TME), tumor-associated macrophages (TAMs) are the most abundant leukocyte population that are associated with poor prognosis in over 80% of breast cancer cases. However, little is known about the effect of resveratrol in the TME.

METHODS

In this study, MDA-MB-231(MB231), cisplatin resistance MDA-MB-231 (cisR), and T47D were used to examine the antitumor effect of resveratrol. The effectiveness of resveratrol, together with cisplatin as breast cancer treatment was investigated in vivo. Gene expressions of M1 (iNOS and CXCL10) and M2 (ARG1, CD163 and MRC1) markers in differentiated macrophages derived from THP-1 cells were examined to investigate the effect of resveratrol on TAM polarization in breast cancer progression.

RESULTS

Our results demonstrated that resveratrol significantly reduced cell proliferation and enhanced chemosensitivity in breast cancer cells by inhibiting production of IL-6 and STAT3 activation. Treatment of resveratrol increased CXCL10 (M1 marker) expression. Further, resveratrol decreased IL-6 levels in LPS-treated differentiated macrophages. The use of resveratrol with cisplatin inhibited suppressed tumor growth when compared with cisplatin alone.

CONCLUSION

This study revealed that resveratrol inhibited breast cancer cell proliferation by promoting M1/M2 macrophage polarization ratio and suppressing IL-6/pSTAT3 pathway.

Identification of a prognostic chemoresistance-related gene signature associated with immune microenvironment in breast cancer

Breast cancer is the most common form of cancer among women globally, and chemoresistance is a major challenge to disease treatment that is associated with a poor prognosis. This study was formulated to identify a reliable prognostic biosignature capable of predicting the survival of patients with chemoresistant breast cancer (CRBC) and evaluating the associated tumor immune microenvironment. Through a series of protein-protein interaction and weighted correlation network analyses, genes that were significantly associated with breast cancer chemoresistance were identified. Moreover, univariate Cox regression and lasso-penalized Cox regression analyses were employed to generate a prognostic model, and the prognostic utility of this model was then assessed using time-dependent receiver operating characteristic (ROC) and Kaplan-Meier survival curves. Finally, The CIBERSORT and ESTIMATE algorithms were additionally leveraged to assess relationships between the tumor immune microenvironment and patient prognostic signatures. Overall, a multigenic prognostic biosignature capable of predicting CRBC patient risk was successfully developed based on bioinformatics analysis and in vitro experiments. This biosignature was able to stratify CRBC patients into high- and low-risk subgroups. ROC curves also revealed that this biosignature achieved high diagnostic efficiency, and multivariate regression analyses indicated that this risk signature was an independent risk factor linked to CRBC patient outcomes. In addition, this signature was associated with the infiltration of the tumor microenvironment by multiple immune cell types. In conclusion, the chemoresistance-associated prognostic gene signature developed herein was able to effectively evaluate the prognosis of CRBC patients and to reflect the overall composition of the tumor immune microenvironment.

Application of LDH assay for therapeutic efficacy evaluation of ex vivo tumor models

The current standard preclinical oncology models are not able to fully recapitulate therapeutic targets and clinically relevant disease biology, evidenced by the 90% attrition rate of new therapies in clinical trials. Three-dimensional (3D) culture systems have the potential to enhance the relevance of preclinical models. However, the limitations of currently available cellular assays to accurately evaluate therapeutic efficacy in these models are hindering their widespread adoption. We assessed the compatibility of the lactate dehydrogenase (LDH) assay in 3D spheroid cultures against other commercially available readout methods. We developed a standardized protocol to apply the LDH assay to ex vivo cultures, considering the impact of culture growth dynamics. We show that accounting for growth rates and background release levels of LDH are sufficient to make the LDH assay a suitable methodology for longitudinal monitoring and endpoint assessment of therapeutic efficacy in both cell line-derived xenografts (xenospheres) and patient-derived explant cultures. This method has the added value of being non-destructive and not dependent on reagent penetration or manipulation of the parent material. The establishment of reliable readout methods for complex 3D culture systems will further the utility of these tumor models in preclinical and co-clinical drug development studies.

The tumor microenvironment as driver of stemness and therapeutic resistance in breast cancer: New challenges and therapeutic opportunities

BACKGROUND

Breast cancer (BC), the second most common cause of cancer-related deaths, remains a significant threat to the health and wellness of women worldwide. The tumor microenvironment (TME), comprising cellular components, such as cancer-associated fibroblasts (CAFs), immune cells, endothelial cells and adipocytes, and noncellular components such as extracellular matrix (ECM), has been recognized as a critical contributor to the development and progression of BC. The interplay between TME components and cancer cells promotes phenotypic heterogeneity, cell plasticity and cancer cell stemness that impart tumor dormancy, enhanced invasion and metastasis, and the development of therapeutic resistance. While most previous studies have focused on targeting cancer cells with a dismal prognosis, novel therapies targeting stromal components are currently being evaluated in preclinical and clinical studies, and are already showing improved efficacies. As such, they may offer better means to eliminate the disease effectively.

CONCLUSIONS

In this review, we focus on the evolving concept of the TME as a key player regulating tumor growth, metastasis, stemness, and the development of therapeutic resistance. Despite significant advances over the last decade, several clinical trials focusing on the TME have failed to demonstrate promising effectiveness in cancer patients. To expedite clinical efficacy of TME-directed therapies, a deeper understanding of the TME is of utmost importance. Secondly, the efficacy of TME-directed therapies when used alone or in combination with chemo- or radiotherapy, and the tumor stage needs to be studied. Likewise, identifying molecular signatures and biomarkers indicating the type of TME will help in determining precise TME-directed therapies.

CXCL2-mediated ATR/CHK1 signaling pathway and platinum resistance in epithelial ovarian cancer

Tumor microenvironment and chemokines play a significant role in cancer chemoresistance. This study was designed to reveal the important role of CXCL2 in platinum resistance in epithelial ovarian cancer (EOC). Differently expressed (DE) genes were screen out based on analysis of GSE114206 dataset in GEO database. The expression of DE chemokines was further validated in platinum- resistant and sensitive EOC. Cell viability assay and cell apoptosis assay were performed to explore the roles of CXCL2 in EOC. Cell stemness characteristics and the signaling pathway regulated by CXCL2 were also investigated in this study. As the results showed, CXCL2 was identified up-regulated in platinum-resistant EOC. The functional assays showed overexpressing CXCL2 or co-culturing with recombinant human CXCL2 promoted cell resistance to cisplatin. Conversely, knocking down CXCL2 or co-culturing with neutralizing antibody to CXCL2 increased cell response to cisplatin. CXCL2 overexpressing maintained cell stemness and activated ATR/CHK1 signaling pathway in EOC. Moreover, we further demonstrated that CXCL2-mediated resistance to cisplatin could be saved by SB225002, the inhibitor of CXCL2 receptor, as well as be rescued by SAR-020106, the inhibitor of ATR/CHK1 signaling pathway. This study identified a CXCL2-mediated mechanism in EOC platinum resistance. Our findings provided a novel target for chemoresistance prevention in EOC.

Tumor Microenvironment in Breast Cancer-Updates on Therapeutic Implications and Pathologic Assessment

The tumor microenvironment (TME) in breast cancer comprises local factors, cancer cells, immune cells and stromal cells of the local and distant tissues. The interaction between cancer cells and their microenvironment plays important roles in tumor proliferation, propagation and response to therapies. There is increasing research in exploring and manipulating the non-cancerous components of the TME for breast cancer treatment. As the TME is now increasingly recognized as a treatment target, its pathologic assessment has become a critical component of breast cancer management. The latest WHO classification of tumors of the breast listed stromal response pattern/fibrotic focus as a prognostic factor and includes recommendations on the assessment of tumor infiltrating lymphocytes and PD-1/PD-L1 expression, with therapeutic implications. This review dissects the TME of breast cancer, describes pathologic assessment relevant for prognostication and treatment decision, and details therapeutic options that interacts with and/or exploits the TME in breast cancer.

LINC00337 induces tumor development and chemoresistance to paclitaxel of breast cancer by recruiting M2 tumor-associated macrophages

BACKGROUND

M2 tumor-associated macrophages are closely related to the progression and prognosis of breast cancer (BCa), and could be regulated by long intergenic non-coding RNAs (lincRNAs). Moreover, the differential expression of lincRNAs affects tumor resistance. This study focused on the potential involvement and mechanism of LINC00337 in BCa.

METHODS

The expression of LINC00337 in BCa was detected by bioinformatics analysis and RT-qPCR. Cell viability and proliferation were analyzed by cell counting kit-8 (CCK-8) and clone formation assay. BCa cells were treated with different concentrations of paclitaxel (PAX) to determine the chemotherapy resistance of LINC00337. Tumor formation assay, Western blot, ELISA and immunohistochemistry were performed to determine the relationship between LINC00337 and PAX in vivo. Macrophages were induced to M2-like polarization, and then functional experiments (CCK-8, wound healing) and molecular experiments (ELISA, RT-qPCR, Western blot) were used to verify the role of LINC00337.

RESULTS

LINC00337 was up-regulated in BCa. High-expressed LINC00337 accelerated viability and proliferation of BCa cells, improved the resistance of BCa cells to PAX, and accelerated tumor growth. Overexpressed LINC00337 up-regulated the expressions of M2 macrophage markers and M-CSF, and reduced the level of GM-CSF. PAX significantly reduced the viability of BCa cells and down-regulated LINC00337. Furthermore, the successfully induced M2 type macrophages to promote BCa cell activity, migration and EMT protein expression, and LINC00337 enhanced the effect of M2 type macrophages. ShLINC00337 had the opposite effect to overexpressed LINC00337.

CONCLUSION

LINC00337 accelerated the malignant phenotype of BCa cells and promoted chemoresistance to paclitaxel through M2-like macrophages.

Crosstalk between Tumor-Infiltrating Immune Cells and Cancer-Associated Fibroblasts in Tumor Growth and Immunosuppression of Breast Cancer

Signals from the tumor microenvironment (TME) have a profound influence on the maintenance and progression of cancers. Chronic inflammation and the infiltration of immune cells in breast cancer (BC) have been strongly associated with early carcinogenic events and a switch to a more immunosuppressive response. Cancer-associated fibroblasts (CAFs) are the most abundant stromal component and can modulate tumor progression according to their secretomes. The immune cells including tumor-infiltrating lymphocytes (TILs) (cytotoxic T cells (CTLs), regulatory T cells (Tregs), and helper T cell (Th)), monocyte-infiltrating cells (MICs), myeloid-derived suppressor cells (MDSCs), mast cells (MCs), and natural killer cells (NKs) play an important part in the immunological balance, fluctuating TME between protumoral and antitumoral responses. In this review article, we have summarized the impact of these immunological players together with CAF secreted substances in driving BC progression. We explain the crosstalk of CAFs and tumor-infiltrating immune cells suppressing antitumor response in BC, proposing these cellular entities as predictive markers of poor prognosis. CAF-tumor-infiltrating immune cell interaction is suggested as an alternative therapeutic strategy to regulate the immunosuppressive microenvironment in BC.

Identification of Dipeptidyl Peptidase (DPP) Family Genes in Clinical Breast Cancer Patients via an Integrated Bioinformatics Approach

Breast cancer is a heterogeneous disease involving complex interactions of biological processes; thus, it is important to develop therapeutic biomarkers for treatment. Members of the dipeptidyl peptidase (DPP) family are metalloproteases that specifically cleave dipeptides. This family comprises seven members, including DPP3, DPP4, DPP6, DPP7, DPP8, DPP9, and DPP10; however, information on the involvement of DPPs in breast cancer is lacking in the literature. As such, we aimed to study their roles in this cancerous disease using publicly available databases such as cBioportal, Oncomine, and Kaplan–Meier Plotter. These databases comprise comprehensive high-throughput transcriptomic profiles of breast cancer across multiple datasets. Furthermore, together with investigating the messenger RNA expression levels of these genes, we also aimed to correlate these expression levels with breast cancer patient survival. The results showed that DPP3 and DPP9 had significantly high expression profiles in breast cancer tissues relative to normal breast tissues. High expression levels of DPP3 and DPP4 were associated with poor survival of breast cancer patients, whereas high expression levels of DPP6, DPP7, DPP8, and DPP9 were associated with good prognoses. Additionally, positive correlations were also revealed of DPP family genes with the cell cycle, transforming growth factor (TGF)-beta, kappa-type opioid receptor, and immune response signaling, such as interleukin (IL)-4, IL6, IL-17, tumor necrosis factor (TNF), and interferon (IFN)-alpha/beta. Collectively, DPP family members, especially DPP3, may serve as essential prognostic biomarkers in breast cancer.

Engineering Breast Cancer On-chip-Moving Toward Subtype Specific Models

Breast cancer is the second leading cause of death among women worldwide, and while hormone receptor positive subtypes have a clear and effective treatment strategy, other subtypes, such as triple negative breast cancers, do not. Development of new drugs, antibodies, or immune targets requires significant re-consideration of current preclinical models, which frequently fail to mimic the nuances of patient-specific breast cancer subtypes. Each subtype, together with the expression of different markers, genetic and epigenetic profiles, presents a unique tumor microenvironment, which promotes tumor development and progression. For this reason, personalized treatments targeting components of the tumor microenvironment have been proposed to mitigate breast cancer progression, particularly for aggressive triple negative subtypes. To-date, animal models remain the gold standard for examining new therapeutic targets; however, there is room for in vitro tools to bridge the biological gap with humans. Tumor-on-chip technologies allow for precise control and examination of the tumor microenvironment and may add to the toolbox of current preclinical models. These new models include key aspects of the tumor microenvironment (stroma, vasculature and immune cells) which have been employed to understand metastases, multi-organ interactions, and, importantly, to evaluate drug efficacy and toxicity in humanized physiologic systems. This review provides insight into advanced in vitro tumor models specific to breast cancer, and discusses their potential and limitations for use as future preclinical patient-specific tools.

Therapy Resistance in Cancers: Phenotypic, Metabolic, Epigenetic and Tumour Microenvironmental Perspectives

BACKGROUND

Chemoresistance is a vital problem in cancer therapy where cancer cells develop mechanisms to encounter the effect of chemotherapeutics, resulting in cancer recurrence. In addition, chemotherapy- resistant leads to the formation of a more aggressive form of cancer cells, which, in turn, contributes to the poor survival of patients with cancer.

OBJECTIVE

In this review, we aimed to provide an overview of how the therapy resistance property evolves in cancer cells, contributing factors and their role in cancer chemoresistance, and exemplified the problems of some available therapies.

METHODS

The published literature on various electronic databases including, Pubmed, Scopus, Google scholar containing keywords cancer therapy resistance, phenotypic, metabolic and epigenetic factors, were vigorously searched, retrieved and analyzed.

RESULTS

Cancer cells have developed a range of cellular processes, including uncontrolled activation of Epithelial- Mesenchymal Transition (EMT), metabolic reprogramming and epigenetic alterations. These cellular processes play significant roles in the generation of therapy resistance. Furthermore, the microenvironment where cancer cells evolve effectively contributes to the process of chemoresistance. In tumour microenvironment immune cells, Mesenchymal Stem Cells (MSCs), endothelial cells and cancer-associated fibroblasts (CAFs) contribute to the maintenance of therapy-resistant phenotype via the secretion of factors that promote resistance to chemotherapy.

CONCLUSION

To conclude, as these factors hinder successful cancer therapies, therapeutic resistance property of cancer cells is a subject of intense research, which in turn could open a new horizon to aim for developing efficient therapies.

Tryptanthrin exerts anti-breast cancer effects both in vitro and in vivo through modulating the inflammatory tumor microenvironment

Tryptanthrin is an indole quinazoline alkaloid from the indigo-bearing plants, such as Isatis indigotica Fort. Typically, this natural compound shows a variety of pharmacological activities such as antitumor, antibacterial, anti-inflammatory and antioxidant effects. This study was conducted to assess the antitumor activity of tryptanthrin in breast cancer models both in vitro and in vivo, and to explore the important role of the inflammatory tumor microenvironment (TME) in the antitumor effects of tryptanthrin. Human breast adenocarcinoma MCF-7 cells were used to assess the antitumor effect of tryptanthrin in vitro. MTT assay and colony formation assay were carried out to monitor the antiproliferative effect of tryptanthrin (1.56~50.0 μmol L-1) on inhibiting the proliferation and colony formation of MCF-7 cells, respectively. The migration and invasion of MCF-7 cells were evaluated by wound healing assay and Transwell chamber assay, respectively. Moreover, the 4T1 murine breast cancer model was established to examine the pharmacological activity of tryptanthrin, and three groups with different doses of tryptanthrin (25, 50 and 100 mg kg-1) were set in study. Additionally, tumor volumes and organ coefficients were measured and calculated. After two weeks of tryptanthrin treatment, samples from serum, tumor tissue and different organs from tumor-bearing mice were collected, and the enzyme-linked immunosorbent assay (ELISA) was performed to assess the regulation of inflammatory molecules in mouse serum. Additionally, pathological examinations of tumor tissues and organs from mice were evaluated through hematoxylin and eosin (H&E) staining. The expression of inflammatory proteins in tumor tissues was measured by immunohistochemistry (IHC) and Western blotting. Tryptanthrin inhibited the proliferation, migration and invasion of MCF-7 cells, up-regulated the protein level of E-cadherin, and down-regulated those of MMP-2 and Snail, as suggested by the MCF-7 cell experiment. According to the results from in vivo experiment, tryptanthrin was effective in inhibiting tumor growth, and it showed favorable safety without inducing the fluctuations of body mass and organ coefficient (p > 0.05). In addition, tryptanthrin also suppressed the expression levels of NOS1, COX-2 and NF-κB in mouse tumor tissues, and regulated those of IL-2, IL-10 and TNF-α in the serum of tumor cells-transplanted mice. Tryptanthrin exerted its anti-breast cancer activities through modulating the inflammatory TME both in vitro and in vivo.

Not Only Immune Escape-The Confusing Role of the TRP Metabolic Pathway in Carcinogenesis

BACKGROUND

The recently discovered phenomenon that cancer cells can avoid immune response has gained scientists' interest. One of the pathways involved in this process is tryptophan (TRP) metabolism through the kynurenine pathway (KP). Individual components involved in TRP conversion seem to contribute to cancerogenesis both through a direct impact on cancer cells and the modulation of immune cell functionality. Due to this fact, this pathway may serve as a target for immunotherapy and attempts are being made to create novel compounds effective in cancer treatment. However, the results obtained from clinical trials are not satisfactory, which raises questions about the exact role of KP elements in tumorigenesis. An increasing number of experiments reveal that TRP metabolites may either be tumor promoters and suppressors and this is why further research in this field is highly needed. The aim of this study is to present KP as a modulator of cancer development through multiple mechanisms and to point to its ambiguity, which may be a reason for failures in treatment based on the inhibition of tryptophan metabolism.

Current Knowledge of Long Non-Coding RNA HOTAIR in Breast Cancer Progression and Its Application

Breast cancer is one of the most devastating cancers with high morbidity and mortality in females worldwide. Breast tumorigenesis and further development present great uncertainty and complexity, and efficient therapeutic approaches still lack. Accumulating evidence indicates HOX transcript antisense intergenic RNA (HOTAIR) is dysregulated in cancers and has emerged as a novel hotspot in the field. In breast cancer, aberrant HOTAIR expression is responsible for advanced tumor progression by regulating multifarious signaling pathways. Besides, HOTAIR may act as competitive endogenous RNA to bind to several microRNAs and suppress their expressions, which can subsequently upregulate the levels of targeted downstream messenger RNAs, thereby leading to further cancer progression. In addition, HOTAIR works as a promising biomarker and predictor for breast cancer patients’ diagnosis or outcome prediction. Recently, HOTAIR is potentially considered to be a drug target. Here, we have summarized the induction of HOTAIR in breast cancer and its impacts on cell proliferation, migration, apoptosis, and therapeutic resistance, as well as elucidating the underlying mechanisms. This review aims to provide new insights into investigations between HOTAIR and breast cancer development and inspire new methods for studying the association in depth.

Mining immune-related genes with prognostic value in the tumor microenvironment of breast invasive ductal carcinoma

ABSTRACT

The tumor microenvironment (TME) plays an important role in the development of breast cancer. Due to limitations in experimental conditions, the molecular mechanism of TME in breast cancer has not yet been elucidated. With the development of bioinformatics, the study of TME has become convenient and reliable.Gene expression and clinical feature data were downloaded from The Cancer Genome Atlas database and the Molecular Taxonomy of Breast Cancer International Consortium database. Immune scores and stromal scores were calculated using the Estimation of Stromal and Immune Cells in Malignant Tumor Tissues Using Expression Data algorithm. The interaction of genes was examined with protein-protein interaction and co-expression analysis. The function of genes was analyzed by gene ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes analysis and gene set enrichment analysis. The clinical significance of genes was assessed with Kaplan-Meier analysis and univariate/multivariate Cox regression analysis.Our results showed that the immune scores and stromal scores of breast invasive ductal carcinoma (IDC) were significantly lower than those of invasive lobular carcinoma. The immune scores were significantly related to overall survival of breast IDC patients and both the immune and stromal scores were significantly related to clinical features of these patients. According to the level of immune/stromal scores, 179 common differentially expressed genes and 5 hub genes with prognostic value were identified. In addition, the clinical significance of the hub genes was validated with data from the molecular taxonomy of breast cancer international consortium database, and gene set enrichment analysis analysis showed that these hub genes were mainly enriched in signaling pathways of the immune system and breast cancer.We identified five immune-related hub genes with prognostic value in the TME of breast IDC, which may partly determine the prognosis of breast cancer and provide some direction for development of targeted treatments in the future.

Analysis of LAGEs Family Gene Signature and Prognostic Relevance in Breast Cancer

Breast cancer (BRCA) is one of the most complex diseases and involves several biological processes. Members of the L-antigen (LAGE) family participate in the development of various cancers, but their expressions and prognostic values in breast cancer remain to be clarified. High-throughput methods for exploring disease progression mechanisms might play a pivotal role in the improvement of novel therapeutics. Therefore, gene expression profiles and clinical data of LAGE family members were acquired from the cBioportal database, followed by verification using the Oncomine and The Cancer Genome Atlas (TCGA) databases. In addition, the Kaplan-Meier method was applied to explore correlations between expressions of LAGE family members and prognoses of breast cancer patients. MetaCore, GlueGo, and GluePedia were used to comprehensively study the transcript expression signatures of LAGEs and their co-expressed genes together with LAGE-related signal transduction pathways in BRCA. The result indicated that higher LAGE3 messenger (m)RNA expressions were observed in BRCA tissues than in normal tissues, and they were also associated with the stage of BRCA patients. Kaplan-Meier plots showed that overexpression of LAGE1, LAGE2A, LAGE2B, and LAGE3 were highly correlated to poor survival in most types of breast cancer. Significant associations of LAGE family genes were correlated with the cell cycle, focal adhesion, and extracellular matrix (ECM) receptor interactions as indicated by functional enrichment analyses. Collectively, LAGE family members' gene expression levels were related to adverse clinicopathological factors and prognoses of BRCA patients; therefore, LAGEs have the potential to serve as prognosticators of BRCA patients.

Tumor microenvironment promotes breast cancer chemoresistance

Breast cancer is presently the most predominant tumor type and the second leading cause of tumor-related deaths among women. Although advancements in diagnosis and therapeutics have momentously improved, chemoresistance remains an important challenge. Tumors oppose chemotherapeutic agents through a variety of mechanisms, with studies revealing that the tumor microenvironment (TME) is central to this process. The components of TME including stromal cells, immune cells, and non-stromal factors on exposure to chemotherapy promote the acquisition of resistant phenotype. Consequently, limited targeting of tumor cells leads to tumor recurrence after chemotherapy. Here, in this article, we summarize how TME alters chemotherapy responses in breast cancer. Furthermore, the role of different stromal cells viz., CAFs, TAMs, MSCs, endothelial cells, and cancer stem cells (CSC) in breast cancer chemoresistance is discussed in greater detail.

Potential roles and prognostic significance of exosomes in cancer drug resistance

Drug resistance is a major impediment in cancer therapy which strongly reduces the efficiency of anti-cancer drugs. Exosomes are extracellular vesicles with cup or spherical shape with a size range of 40-150 nm released by eukaryotic cells that contain genetic materials, proteins, and lipids which mediate a specific cell-to-cell communication. The potential roles of exosomes in intrinsic and acquired drug resistance have been reported in several studies. Furthermore, a line of evidence suggested that the content of exosomes released from tumor cells in biological samples may be associated with the clinical outcomes of cancer patients. In this review, we highlighted the recent studies regarding the potential roles of exosomes in tumor initiation, progression, and chemoresistance. This study suggests the possible role of exosomes for drug delivery and their contents in prognosis and resistance to chemotherapy in cancer patients.

Microengineered 3D Tumor Models for Anti-Cancer Drug Discovery in Female-Related Cancers

The burden of cancer continues to increase in society and negatively impacts the lives of numerous patients. Due to the high cost of current treatment strategies, there is a crucial unmet need to develop inexpensive preclinical platforms to accelerate the process of anti-cancer drug discovery to improve outcomes in cancer patients, most especially in female patients. Many current methods employ expensive animal models which not only present ethical concerns but also do not often accurately predict human physiology and the outcomes of anti-cancer drug responsiveness. Conventional treatment approaches for cancer generally include systemic therapy after a surgical procedure. Although this treatment technique is effective, the outcome is not always positive due to various complex factors such as intratumor heterogeneity and confounding factors within the tumor microenvironment (TME). Patients who develop metastatic disease still have poor prognosis. To that end, recent efforts have attempted to use 3D microengineered platforms to enhance the predictive power and efficacy of anti-cancer drug screening, ultimately to develop personalized therapies. Fascinating features of microengineered assays, such as microfluidics, have led to the advancement in the development of the tumor-on-chip technology platforms, which have shown tremendous potential for meaningful and physiologically relevant anti-cancer drug discovery and screening. Three dimensional microscale models provide unprecedented ability to unveil the biological complexities of cancer and shed light into the mechanism of anti-cancer drug resistance in a timely and resource efficient manner. In this review, we discuss recent advances in the development of microengineered tumor models for anti-cancer drug discovery and screening in female-related cancers. We specifically focus on female-related cancers to draw attention to the various approaches being taken to improve the survival rate of women diagnosed with cancers caused by sex disparities. We also briefly discuss other cancer types like colon adenocarcinomas and glioblastoma due to their high rate of occurrence in females, as well as the high likelihood of sex-biased mutations which complicate current treatment strategies for women. We highlight recent advances in the development of 3D microscale platforms including 3D tumor spheroids, microfluidic platforms as well as bioprinted models, and discuss how they have been utilized to address major challenges in the process of drug discovery, such as chemoresistance, intratumor heterogeneity, drug toxicity, etc. We also present the potential of these platform technologies for use in high-throughput drug screening approaches as a replacements of conventional assays. Within each section, we will provide our perspectives on advantages of the discussed platform technologies.

S100A9-Imaging Enables Estimation of Early Therapy-Mediated Changes in the Inflammatory Tumor Microenvironment

(1) Background: The prognosis of cancer is dependent on immune cells in the tumor microenvironment (TME). The protein S100A9 is an essential regulator of the TME, associated with poor prognosis. In this study, we evaluated early therapy effects on the TME in syngeneic murine breast cancer via S100A9-specific in vivo imaging. (2) Methods: Murine 4T1 cells were implanted orthotopically in female BALB/c mice (n = 59). Tumor size-adapted fluorescence imaging was performed before and 5 days after chemo- (Doxorubicin, n = 20), anti-angiogenic therapy (Bevacizumab, n = 20), or placebo (NaCl, n = 19). Imaging results were validated ex vivo (immunohistochemistry, flow cytometry). (3) Results: While tumor growth revealed no differences (p = 0.48), fluorescence intensities (FI) for S100A9 in Bevacizumab-treated tumors were significantly lower as compared to Doxorubicin (2.60 vs. 15.65 AU, p < 0.0001). FI for Doxorubicin were significantly higher compared to placebo (8.95 AU, p = 0.01). Flow cytometry revealed shifts in monocytic and T-cell cell infiltrates under therapy, correlating with imaging. (4) Conclusions: S100A9-specific imaging enables early detection of therapy effects visualizing immune cell activity in the TME, even before clinically detectable changes in tumor size. Therefore, it may serve as a non-invasive imaging biomarker for early therapy effects.