Radiation therapy in the locoregional treatment of triple-negative breast cancer

Engineered Bacterial Biohybrid-Mediated CD47-SIRPα Blockade and HSP90 Inhibition for Enhanced Immuno-Photothermal Therapy

Macrophage phagocytosis of tumor cells shows significant promise in cancer treatment. However, it faces great challenges due to the upregulation of antiphagocytosis molecules, such as CD47, on the surface of tumor cells. Merely reducing the level of CD47 is insufficient to induce phagocytosis of tumor cells because it lacks enough "eat me" signals. Here, we have developed an engineered bacterial biohybrid system (eVNP@AuNFs) to decrease the expression of CD47 and HSP90 proteins, achieving an enhanced immuno-photothermal combination therapy. The attenuated Salmonella VNP20009, capable of selectively accumulating in hypoxic tumor regions, was intracellularly genetically engineered with CD47 and HSP90 shRNA plasmids and an extracellularly adsorbed flower-like gold nanoparticle (AuNF) photothermal agent, forming an eVNP@AuNF bacterial hybrid. After administration into 4T1 tumor-bearing mice intravenously, the eVNP@AuNF bacterial hybrid could effectively accumulate in tumor tissues and release CD47 and HSP90 shRNA plasmids to reduce the expression of CD47 and HSP90 protein, leading to enhanced macrophage phagocytosis to tumor cells and an improved photothermal effect. Under further NIR-II laser irradiation, extracellular AuNFs of eVNP@AuNFs could photothermally induce immunogenic cell death, including surface calreticulin exposure and high-mobility group box 1 translocation, facilitating the infiltration of the "eat me" signal and multiple immune cells and enhancing tumor immunogenicity. The eVNP@AuNF bacterial hybrid could eradicate the primary tumor and elicit a systemic antitumor immunity response, inhibiting the recurrence of the tumor. This study presents a hybrid system involving bacteria, plasmids, and nanomaterials for tumor therapy, opening an avenue for hierarchical modulation of the tumor immune response.

Resistance to Radiation Enhances Metastasis by Altering RNA Metabolism

The cellular programs that mediate therapy resistance are often important drivers of metastasis, a phenomenon that needs to be understood better to improve screening and treatment options for cancer patients. Although this issue has been studied extensively for chemotherapy, less is known about a causal link between resistance to radiation therapy and metastasis. We investigated this problem in triple-negative breast cancer (TNBC) and established that radiation resistant tumor cells have enhanced metastatic capacity, especially to bone. Resistance to radiation increases the expression of integrin β3 (ITGβ3), which promotes enhanced migration and invasion. Bioinformatic analysis and subsequent experimentation revealed an enrichment of RNA metabolism pathways that stabilize ITGβ3 transcripts. Specifically, the RNA binding protein heterogenous nuclear ribonucleoprotein L (HNRNPL), whose expression is regulated by Nrf2, mediates the formation of circular RNAs (circRNAs) that function as competing endogenous RNAs (ceRNAs) for the family of let-7 microRNAs that target ITGβ3. Collectively, our findings identify a novel mechanism of radiation-induced metastasis that is driven by alterations in RNA metabolism.

Neuropilin-2-expressing breast cancer cells mitigate radiation-induced oxidative stress through nitric oxide signaling

The high rate of recurrence after radiation therapy in triple-negative breast cancer (TNBC) indicates that novel approaches and targets are needed to enhance radiosensitivity. Here, we report that neuropilin-2 (NRP2), a receptor for vascular endothelial growth factor (VEGF) that is enriched on subpopulations of TNBC cells with stem cell properties, is an effective therapeutic target for sensitizing TNBC to radiotherapy. Specifically, VEGF/NRP2 signaling induces nitric oxide synthase 2 (NOS2) transcription by a mechanism dependent on Gli1. NRP2-expressing tumor cells serve as a hub to produce nitric oxide (NO), an autocrine and paracrine signaling metabolite, which promotes cysteine-nitrosylation of Kelch-like ECH-associated protein 1 (KEAP1) and, consequently, nuclear factor erythroid 2-related factor 2-mediated (NFE2L2-mediated) transcription of antioxidant response genes. Inhibiting VEGF binding to NRP2, using a humanized mAb, results in NFE2L2 degradation via KEAP1, rendering cell lines and organoids vulnerable to irradiation. Importantly, treatment of patient-derived xenografts with the NRP2 mAb and radiation resulted in significant tumor necrosis and regression compared with radiation alone. Together, these findings reveal a targetable mechanism of radioresistance, and they support the use of NRP2 mAb as an effective radiosensitizer in TNBC.

Establishment of prognostic model for invasive ductal carcinoma with distant metastasis within the triple-negative breast cancer: a SEER population-based study

Triple-negative breast cancer (TNBC) is a complex and diverse group of malignancies. Invasive ductal carcinoma (IDC) is the predominant pathological subtype and is closely linked to the ominous potential for distant metastasis, a pivotal factor that significantly influences patient outcomes. In light of these considerations, the present study was conceived with the objective of developing a nomogram model. This model was designed to predict the prognosis observed in IDC with distant metastasis in TNBC. This was a retrospective study based on the SEER database. Data of 9739 IDC-TNBC patients diagnosed from 2010 to 2020 were included in our study. Independent risk factors were screened by univariate and multivariate Cox regression analyses successively, which were used to develop a nomogram model predicting for prognosis. Cox multivariable analysis showed statistical significance in bone metastasis, liver metastasis, surgery, and chemotherapy. Incorporating statistically significant variables, as well as clinically significant age, lung metastasis, and brain metastasis into the construction of the prediction model, the C-indexes of the training group and validation group were 0.702 (0.663-0.741) and 0.667 (0.600-0.734), respectively, while the calibration curves were all close to the ideal 45° reference line, and decision curve analysis curves show excellent net benefit in the predictive model. The prognostic prediction model developed in this study demonstrated enhanced predictive accuracy, enabling a more precise evaluation of mortality risks associated with IDC with distant metastasis in TNBC.

Treatment Outcomes after Postoperative Radiotherapy in Triple-Negative Breast Cancer: Multi-Institutional Retrospective Study (KROG 17-05)

BACKGROUND

We designed a multi-institutional retrospective study to investigate the previously unreported failure pattern, survivals, and prognostic factors after postoperative radiotherapy (PORT) in triple negative breast cancer (TNBC) patients in South Korea.

MATERIALS AND METHODS

We retrospectively reviewed 699 patients with TNBC who underwent PORT at six institutions between 2008 and 2010. The median follow-up period was 94 months (range: 7-192 months). There were 216, 380, and 100 patients in stages I, II, and III, respectively.

RESULTS

After 94 months post-treatment, all patients with pathologic complete remission after neoadjuvant chemotherapy were alive without any failure. Distant metastasis was the main cause of failure. The 5-year overall survival rate was 91.4%, 5-year loco-regional relapse-free survival rate (LRRFS) was 92.3%, 5-year distant metastasis-free survival rate (DMFS) was 89.4%, and 5-year disease-free survival rate (DFS) was 85.2%. On multivariate (Cox) analysis, T and N stages were significant prognostic factors for survival, and lympho-vascular invasion (LVI) was a significant factor for LRRFS and DMFS. Ki-67 expression was significantly associated with LRRFS and DFS.

CONCLUSION

We verified that T and N stages, LVI, and Ki-67 expression were significantly associated with survival outcomes after PORT in TNBC.

Role of AURKB Inhibition in Reducing Proliferation and Enhancing Effects of Radiotherapy in Triple-Negative Breast Cancer

Breast cancer is a leading cause of cancer-related deaths in females. Triple-negative breast cancer (TNBC) subtype is the most aggressive form of breast cancer that lacks biomarkers and effective targeted therapies. Its high degree of heterogeneity as well as innate and acquired resistance to treatment creates further barriers in achieving positive clinical outcomes in TNBC. Thus, development of novel treatment approaches in TNBC is of high clinical significance. Multimodality approaches with targeted agents and radiotherapy (RT) are promising for increasing efficacy of treatment and circumventing resistance. Here we examined anticancer effects of the Aurora Kinase B (AURKB) inhibitor AZD1152 as a single agent and in combination with RT using various TNBC cell lines, MDA-MB-468, MDA-MB-231 and SUM-159. We observed that AZD1152 alone effectively inhibited colony formation in TNBC cell lines. The combination of AZD1152 at IC50 concentrations together with ionizing radiation further reduced colony formation as compared to the single agent treatment. Our data support the notion that inhibition of the AURKB pathway is a promising strategy for treatment and radiosensitization of TNBC and warrants further translational studies.

Role of non-coding RNAs mediated pyroptosis on cancer therapy: a review

INTRODUCTION

Non-coding RNAs (ncRNAs), which are incapable of encoding proteins, are involved in the progression of numerous tumors by altering transcriptional and post-transcriptional processing. Recent studies have revealed prominent features of ncRNAs in pyroptosis, a type of non-apoptotic programmed cellular destruction linked to an inflammatory reaction. Drug resistance has arisen gradually as a result of anti-apoptotic proteins, therefore strategies based on pyroptotic cell death have attracted increasing attention. We have observed that ncRNAs may exert significant influence on cancer therapy, chemotherapy, radio- therapy, targeted therapy and immunotherapy, by regulating pyroptosis.

AREAS COVERED

Literatures were searched (December 2023) for studies on cancer therapy for ncRNAs-mediated pyroptotic cell death.

EXPERT OPINION

The most universal mechanical strategy for ncRNAs to regulate target genes is competitive endogenous RNAs (ceRNA). Besides, certain ncRNAs could directly interact with proteins and modulate downstream genes to induce pyroptosis, resulting in tumor growth or inhibition. In this review, we aim to display that ncRNAs, predominantly long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and circular RNAs (circRNAs), could function as potential biomarkers for diagnosis and prognosis and produce new insights into anti-cancer strategies modulated by pyroptosis for clinical applications.

Protein disulfide isomerase family member 4 promotes triple-negative breast cancer tumorigenesis and radiotherapy resistance through JNK pathway

BACKGROUND

Despite radiotherapy ability to significantly improve treatment outcomes and survival in triple-negative breast cancer (TNBC) patients, acquired resistance to radiotherapy poses a serious clinical challenge. Protein disulfide isomerase exists in endoplasmic reticulum and plays an important role in promoting protein folding and post-translational modification. However, little is known about the role of protein disulfide isomerase family member 4 (PDIA4) in TNBC, especially in the context of radiotherapy resistance.

METHODS

We detected the presence of PDIA4 in TNBC tissues and paracancerous tissues, then examined the proliferation and apoptosis of TNBC cells with/without radiotherapy. As part of the validation process, xenograft tumor mouse model was used. Mass spectrometry and western blot analysis were used to identify PDIA4-mediated molecular signaling pathway.

RESULTS

Based on paired clinical specimens of TNBC patients, we found that PDIA4 expression was significantly higher in tumor tissues compared to adjacent normal tissues. In vitro, PDIA4 knockdown not only increased apoptosis of tumor cells with/without radiotherapy, but also decreased the ability of proliferation. In contrast, overexpression of PDIA4 induced the opposite effects on apoptosis and proliferation. According to Co-IP/MS results, PDIA4 prevented Tax1 binding protein 1 (TAX1BP1) degradation by binding to TAX1BP1, which inhibited c-Jun N-terminal kinase (JNK) activation. Moreover, PDIA4 knockdown suppressed tumor growth xenograft model in vivo, which was accompanied by an increase in apoptosis and promoted tumor growth inhibition after radiotherapy.

CONCLUSIONS

The results of this study indicate that PDIA4 is an oncoprotein that promotes TNBC progression, and targeted therapy may represent a new and effective anti-tumor strategy, especially for patients with radiotherapy resistance.

Transforming Intratumor Bacteria into Immunopotentiators to Reverse Cold Tumors for Enhanced Immuno-chemodynamic Therapy of Triple-Negative Breast Cancer

Immunotherapy of triple-negative breast cancer (TNBC) has an unsatisfactory therapeutic outcome due to an immunologically "cold" microenvironment. Fusobacterium nucleatum (F. nucleatum) was found to be colonized in triple-negative breast tumors and was responsible for the immunosuppressive tumor microenvironment and tumor metastasis. Herein, we constructed a bacteria-derived outer membrane vesicle (OMV)-coated nanoplatform that precisely targeted tumor tissues for dual killing of F. nucleatum and cancer cells, thus transforming intratumor bacteria into immunopotentiators in immunotherapy of TNBC. The as-prepared nanoparticles efficiently induced immunogenic cell death through a Fenton-like reaction, resulting in enhanced immunogenicity. Meanwhile, intratumoral F. nucleatum was killed by metronidazole, resulting in the release of pathogen-associated molecular patterns (PAMPs). PAMPs cooperated with OMVs further facilitated the maturation of dendritic cells and subsequent T-cell infiltration. As a result, the "kill two birds with one stone" strategy warmed up the cold tumor environment, maximized the antitumor immune response, and achieved efficient therapy of TNBC as well as metastasis prevention. Overall, this strategy based on a microecology distinction in tumor and normal tissue as well as microbiome-induced reversal of cold tumors provides new insight into the precise and efficient immune therapy of TNBC.

Adjuvant Auger Electron-Emitting Radioimmunotherapy with [111In]In-DOTA-Panitumumab in a Mouse Model of Local Recurrence and Metastatic Progression of Human Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) has a high risk for recurrence and metastasis. We studied the effectiveness of Auger electron (AE) radioimmunotherapy (RIT) with antiepidermal growth factor receptor (EGFR) panitumumab conjugated with DOTA complexed to 111In ([111In]In-DOTA-panitumumab) for preventing metastatic progression after local treatment of 231/LM2-4 Luc+ human TNBC tumors in the mammary fat pad of NRG mice. Prior to RIT, the primary tumor was resected, and tumor margins were treated with X-irradiation (XRT; 5 days × 6 Gy/d). RIT was administered 1 day post-XRT by intravenous injection of 26 MBq (15 μg) or 2 × 10 MBq (15 μg each) separated by 7 d. These treatments were compared to tumor resection with or without XRT combined with DOTA-panitumumab (15 μg) or irrelevant [111In]In-DOTA-IgG2 (24 MBq; 15 μg), and efficacy was evaluated by Kaplan-Meier survival curves. The effect of [111In]In-DOTA-panitumumab (23 MBq; 15 μg) after tumor resection without local XRT was also studied. Tumor resection followed by XRT and RIT with 26 MBq [111In]In-DOTA-panitumumab significantly increased the median survival to 35 d compared to tumor resection with or without XRT (23-24 d; P < 0.0001). Local treatment with tumor resection and XRT followed by 2 × 10 MBq of [111In]In-DOTA-panitumumab, DOTA-panitumumab, or [111In]In-DOTA-IgG2 did not significantly improve median survival (26 days for all treatments). RIT alone with [111In]In-DOTA-panitumumab postresection of the tumor without XRT increased median survival to 29 days, though this was not significant. Despite significantly improved survival in mice treated with tumor resection, XRT, and RIT with [111In]In-DOTA-panitumumab, all mice eventually succumbed to advanced metastatic disease by 45 d post-tumor resection. SPECT/CT with [111In]In-DOTA-panitumumab, PET/MRI with [64Cu]Cu-DOTA-panitumumab F(ab')2, and PET/CT with [18F]FDG were used to detect recurrent and metastatic disease. Uptake of [111In]In-DOTA-panitumumab at 4 d p.i. in the MFP tumor was 26.8 ± 9.7% ID/g and in metastatic lymph nodes (LN), lungs, and liver was 34.2 ± 26.9% ID/g, 17.5 ± 6.0% ID/g, and 9.4 ± 2.4%ID/g, respectively, while uptake in the lungs (6.0 ± 0.9% ID/g) and liver (5.2 ± 2.9% ID/g) of non-tumor-bearing NRG was significantly lower (P < 0.05). Radiation-absorbed doses in metastatic LN, lungs, and liver were 9.7 ± 6.1, 6.4 ± 2.1, and 10.9 ± 2.7 Gy, respectively. In conclusion, we demonstrated that RIT with [111In]In-DOTA-panitumumab combined with tumor resection and XRT significantly improved the survival of mice with recurrent TNBC. However, the aggressive nature of 231/LM2-4 Luc+ tumors in NRG mice may have contributed to the tumor recurrence and progression observed.

Irradiated Mammary Spheroids Elucidate Mechanisms of Macrophage-Mediated Breast Cancer Recurrence

Introduction

While most patients with triple negative breast cancer receive radiation therapy to improve outcomes, a significant subset of patients continue to experience recurrence. Macrophage infiltration into radiation-damaged sites has been shown to promote breast cancer recurrence in pre-clinical models. However, the mechanisms that drive recurrence are unknown. Here, we developed a novel spheroid model to evaluate macrophage-mediated tumor cell recruitment.

Methods

We characterized infiltrating macrophage phenotypes into irradiated mouse mammary tissue via flow cytometry. We then engineered a spheroid model of radiation damage with primary fibroblasts, macrophages, and 4T1 mouse mammary carcinoma cells using in vivo macrophage infiltration results to inform our model. We analyzed 4T1 infiltration into spheroids when co-cultured with biologically relevant ratios of pro-healing M2:pro-inflammatory M1 macrophages. Finally, we quantified interleukin 6 (IL-6) secretion associated with conditions favorable to tumor cell infiltration, and we directly evaluated the impact of IL-6 on tumor cell invasiveness in vitro and in vivo.

Results

In our in vivo model, we observed a significant increase in M2 macrophages in mouse mammary glands 10 days post-irradiation. We determined that tumor cell motility toward irradiated spheroids was enhanced in the presence of a 2:1 ratio of M2:M1 macrophages. We also measured a significant increase in IL-6 secretion after irradiation both in vivo and in our model. This secretion increased tumor cell invasiveness, and tumor cell invasion and recruitment were mitigated by neutralizing IL-6.

Conclusions

Our work suggests that interactions between infiltrating macrophages and damaged stromal cells facilitate breast cancer recurrence through IL-6 signaling.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-023-00775-x.

Local Treatment of Triple-Negative Breast Cancer: Is Mastectomy Superior to Breast-Conserving Surgery?

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer that lacks the expression of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). TNBC accounts for about 15% of breast cancers and has a poorer prognosis as compared with other subtypes of breast cancer. The more rapid onset of this cancer and its aggressiveness have often convinced breast surgeons that mastectomy could provide better oncological results. However, there is no relevant clinical trial that has assessed differences between breast-conserving surgery (BCS) and mastectomy (M) in these patients. This population-based study aimed to investigate the distinct outcomes between conservative treatment and M in a case series of 289 patients with TNBC treated over a 9-year period. This monocentric study retrospectively evaluated patients with TNBC who underwent upfront surgery at Fondazione Policlinico Agostino Gemelli IRCCS, in Rome, between 1 January 2013 and 31 December 2021. First, the patients were divided in two groups according to the surgical treatment received: BCS vs. M. Then, the patients were stratified into four risk subclasses based on combined T and N pathological staging (T1N0, T1N+, T2-4N0 and T2-4N+). The primary endpoint of the study was to evaluate locoregional disease-free survival (LR-DFS), distant disease-free survival (DDFS) and overall survival (OS) in the different subclasses. We analyzed 289 patients that underwent either breast-conserving surgery (247/289, 85.5%) or mastectomy (42/289, 14.5%). After a median follow-up of 43.2 months (49.7, 22.2-74.3), 28 patients (9.6%) developed a locoregional recurrence, 27 patients (9.0%) showed systemic recurrence and 19 patients (6.5%) died. No significant differences due to type of surgical treatment were observed in the different risk subclasses in terms of locoregional disease-free survival, distant disease-free survival and overall survival. With the limits of a retrospective, single-center study, our data seem to indicate similar efficacy in terms of locoregional control, distant metastasis and overall survival with the use of upfront breast-conserving surgery as compared with radical surgery in the treatment of TNBC. Therefore, TNBC should not be considered to be a contraindication for breast conservation.

Targeting HMGA1 contributes to immunotherapy in aggressive breast cancer while suppressing EMT

Metastasis is an obstacle to the clinical treatment of aggressive breast cancer (BC). Studies have shown that high mobility group A1 (HMGA1) is abnormally expressed in various cancers and mediates tumor proliferation and metastasis. Here, we provided more evidence that HMGA1 mediated epithelial to mesenchymal transition (EMT) through the Wnt/β-catenin pathway in aggressive BC. More importantly, HMGA1 knockdown enhanced antitumor immunity and improved the response to immune checkpoint blockade (ICB) therapy by upregulating programmed cell death ligand 1 (PD-L1) expression. Simultaneously, we revealed a novel mechanism by which HMGA1 and PD-L1 were regulated by the PD-L1/HMGA1/Wnt/β-catenin negative feedback loop in aggressive BC. Taken together, we believe that HMGA1 can serve as a target for the dual role of anti-metastasis and enhancing immunotherapeutic responses.

Predictive value of biological markers in loco-regional recurrence of breast cancer after mastectomy and radiotherapy

Objective

To assess the prognostic usefulness of the human epidermal growth factor receptor-2 (Her 2), the progestin receptor (PR), and the oestrogen receptor (ER) in locoregional recurrence following mastectomy radiotherapy in Egyptian breast cancer patients.

Patients and methods

This retrospective analysis comprised 432 female patients who had received radiation and had a mastectomy and immunohistochemistry reports. The Ethics Committee’s clearance was required before this study could be carried out at the Ain-Shams University hospitals.

Results

A total of 24 individuals developed LRR after a median follow-up period of 68.9 months. Although lymph nodes with more than three exhibited a statistically significant risk for LLR, tumour grade and pT were not significant risk factors. LRR risk rose for those who were HER2-positive and those with TNBC, but Luminal B had a non-significantly greater risk than Luminal A.

Conclusion

For breast cancer patients receiving PMRT, the biological subtype based on the categorization standard from the St. Gallen International Breast Cancer Conference (2013) Expert Panel acts as an accurate prognostic predictor. In HER2-positive and hormonal receptor-positive individuals, trastuzumab treatment significantly reduced the risk of LRR.

Analysis of single-nucleotide polymorphisms in genes associated with triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a rare variant of breast cancer (BC) known to be aggressive and refractory. TNBC lacks effective early diagnostic and therapeutic options leading to poorer outcomes. The genomic landscape and alterations leading to BC and TNBC are vast and unclear. Single nucleotide polymorphisms (SNPs) are a widespread form of genetic alterations with a multi-faceted impact on multiple diseases, including BC and TNBC. In this study, we attempted to construct a framework that could identify genes associated with TNBC and screen the SNPs reported in these genes using a set of computational predictors. This framework helped identify BRCA1, BRCA2, EGFR, PIK3CA, PTEN, and TP53 as recurrent genes associated with TNBC. We found 2%-29% of reported SNPs across genes to be typed pathogenic by all the predictors in the framework. We demonstrate that our framework prediction on BC samples identifies 99% of alterations as pathogenic by at least one predictor and 32% as pathogenic by all the predictors. Our framework could be an initial step in developing an early diagnosis of TNBC and potentially help improve the understanding of therapeutic resistance and sensitivity.

An in vivo and in vitro assessment of the anti-breast cancer activity of crude extract and fractions from Prunella vulgaris L

Prunella vulgaris L.(P. vulgaris) is a perennial herb belonging to the Labiate family and widely distributed in China, Japan, Korea and Europe. Medical monographs and previous studies have shown that P. vulgaris has significant anti-breast cancer activity, and its use in breast treatment has a long history. However, systematically reports about the material basis and mechanism of P. vulgaris on anti-breast cancer activity are limited. In the present study, we first screened the best active fraction from the crude extract (PVE) and ethanol eluted fractions of P. vulgaris by using MDA-MB-231, MCF-7, 4T1 cell models in vitro and a 4T1-BALB/c transplanted tumour mouse breast cancer model in vivo. Furthermore, the anti-breast cancer mechanism of the best active fraction was investigated. The results demonstrated that PVE and ethanol fractions exhibited anti-breast cancer activity, especially with the 50% ethanol eluted fraction (PV50), which effectively regulated the 4T1 cell cycle, inhibited tumour cell proliferation, and promoted cancer cell apoptosis. In case of in vivo assays, PV50 inhibited tumour growth and lung metastasis, as well as inducing cell apoptosis by promoting damage of nuclear DNA and increasing expression of cleaved caspase-3. In addition, the chemical compositions of PV50 were analyzed by HPLC and UPLC-MS/MS, which were identified as flavonoids, moderately polar triterpenes, and a small amount of phenolic acid. The PV50 could be applied as natural sources against breast cancer in the pharmaceutical industry. These findings provide a basis for understanding the mechanism of the anti-breast cancer activity of P. vulgaris.

miR-1290 modulates the radioresistance of triple-negative breast cancer by targeting NLRP3-mediated pyroptosis

PURPOSE

To explore the roles and underlying mechanisms of miR-1290 in determining the sensitivity of triple-negative breast cancer (TNBC) to radiation therapy.

METHODS

ELISA was performed to detect the levels of IL-18 and IL-1β in radiosensitive cells and serum samples. The level of miR-1290 in radiosensitive cells and tissues was assessed by qRT-PCR assay. A luciferase reporter assay was performed to confirm NLRP3 as the target of miR-1290. Functionally, the roles of miR-1290 in TNBC radioresistance were analyzed by transfection of either miR-1290 mimic or miR-1290 inhibitor. Moreover, the involvement of the miR-1290/NLRP3 axis in TNBC radioresistance was analyzed by experiments with a miR-1290 mimic and NLRP3 overexpression. MTT and colony formation assays were used to detect radiation-induced cell viability and proliferation. qRT-PCR and western blot assays were used to detect pyroptosis markers (NLRP3, ACS and caspase-1).

RESULTS

The results showed that radioresistance in TNBC cells was associated with a reduction in pyroptosis. miR-1290 expression was increased in radioresistant cells, and it had higher expression levels in the radioresistant tumor tissues of TNBC patients compared to the radiosensitive samples. The miR-1290 mimic suppressed radiation-induced pyroptosis and reduced the radiosensitivity of TNBC cells. Moreover, we found that NLRP3 was a potential target of miR-1290. Overexpression of NLRP3 partly reversed the effects of miR-1290 on pyroptosis and radioresistance. The mouse models showed that miR-1290 suppressed tumor size, tumor weight and pyroptosis.

CONCLUSIONS

miR-1290/NLRP3-mediated pyroptosis may play an important role in determining radioresistance in TNBC and serve as a novel therapeutic option.

Engineering defected 2D Pd/H-TiO2 nanosonosensitizers for hypoxia alleviation and enhanced sono-chemodynamic cancer nanotherapy

Background

Sonodynamic therapy (SDT) is a burgeoning modality for cancer therapy owing to its high tissue-penetrating capability, controllability and safety. Whereas, the undesirable reactive oxygen species (ROS) yield of sonosensitizers and tumor hypoxia are two vulnerable spots of SDT. Therefore, it is an advisable strategy to augment ROS level and simultaneously relieve hypoxia for SDT to arrive its full potential in cancer treatment.

Results

In this work, the defected two-dimensional (2D) Pd/H-TiO₂ nanosheets (NSs) with triple antineoplastic properties were dexterously elaborated and engineered using a facile one-pot Pd-catalyzed hydrogenation tactic by loading a tiny amount of Pd and then inletting hydrogen flow at atmospheric pressure and temperature. The 2D black Pd/H-TiO₂ NSs with oxygen defects exerted eximious SDT effect based on the decreased bandgap that made it easier for the separation of electrons and holes when triggered by ultrasound as theoretically guided by density functional theory calculations. Additionally, Pd/H-TiO₂ NSs could serve as Fenton-like agents because of the presence of oxygen defects, facilitating the conversion of hydrogen peroxide into hydroxyl radicals for exerting the chemodynamic therapy (CDT). Simultaneously, the introduced tiny Pd component possessed catalase-like activity responsible for oxygen production to ameliorate hypoxic condition and thus contributed to improving SDT and CDT efficacies. Both in vitro and in vivo results provided compelling evidences of high ROS yield and aggrandized sono-chemodynamic effect of Pd/H-TiO₂ nanosonosensitizers with the detailed underlying mechanism investigation by RNA sequencing.

Conclusion

This work delves the profound potential of Pd-catalyzed hydrogenated TiO₂ on oncotherapy, and the effective antineoplastic performance and ignorable therapeutic toxicity make it a powerful competitor among a cornucopia of nanosonosensitizers.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01398-6.

Prognostic Factors and Models for Elderly (≥70 Years Old) Primary Operable Triple-Negative Breast Cancer: Analysis From the National Cancer Database

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. In the elderly (≥70 years old) primary operable (T_1-3N_0-1M₀) TNBC, individualized treatment modalities for this population are pivotal and important, but limited studies are explored.

METHODS

The clinicopathological features of elderly primary operable TNBC patients were retrospectively selected from the Surveillance, Epidemiology, and End Results (SEER) database between January 2010 and December 2015. Kaplan-Meier curves were used to show the survival patterns in the different subgroups. Multivariate Cox analysis was used to identify independent risk factors in the 3-, 5-, and 7- year overall survival (OS) and cancer-specific survival (CSS) in this subpopulation. The predictive model was further developed and validated for clinical use.

RESULT

Between 2010 and 2015 years, a total of 4,761 elderly primary operable TNBC patients were enrolled for the study, with a mean age of 76 years and a median follow-up of 56 months. The multivariate Cox analysis showed that age (increased per year: hazard ratio (HR) = 1.05), race (Asian/Pacific Islander and American Indian/Alaska Native, HR = 0.73), differentiation grade (grade II: HR = 2.01; grade III/IV: HR = 2.67), larger tumor size (T_1c: HR = 1.83; T₂: HR = 2.78; T₃: HR = 4.93), positive N stage (N_1mi: HR = 1.60; N₁: HR = 1.54), receiving radiation therapy (HR = 0.66), and receiving adjuvant chemotherapy (HR = 0.61) were the independent prognostic factors for OS, and a similar prognostic pattern was also determined in CSS. Besides, two nomograms for predicting the 3-, 5-, and 7-year OS and CSS in this population were developed with a favorable concordance index of 0.716 and 0.746, respectively.

CONCLUSION

The results highlight that both radiation and adjuvant chemotherapy are significantly associated with favorable long-term OS and CSS probability in elderly primary operable TNBC patients. Based on the determined independent prognostic factors, the novel nomograms could assist the oncologists to make individualized clinical decisions for the subpopulation at different risks.

THOC2 and THOC5 Regulate Stemness and Radioresistance in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer. Radioresistance and stemness are substantial obstacles to TNBC treatment. The THO complex (THOC) is a subunit of the TRanscription-EXport complex that functions in the coupling of transcription to nascent RNA splicing, elongation, and export. However, its role in regulating TNBC therapeutic resistance is not reported yet. In this study, the authors demonstrate that cancer stem cells are enriched in radioresistant TNBC cells and describe the role of the THOC in regulating TNBC radioresistance and stemness. The authors find that THOC2 and THOC5 are upregulated in radioresistant TNBC cells and associated with a poor prognosis in TNBC patients. Further investigation reveals that THOC2 promotes the stem-like properties and radioresistance of TNBC cells in a THOC5-dependent manner by facilitating the release of sex-determining region Y (SRY)-box transcription factor 2 (SOX2) and homeobox transcription factor (NANOG) transcripts from the nucleus. Silencing THOC2 or THOC5 expression decreases the protein expression of SOX2 and NANOG, depletes the stem-like properties, and causes radiosensitization in these TNBC cells. Moreover, THOC2 or THOC5 depletion blocks the xenograft tumorigenesis and growth of radioresistant TNBC in vivo. These findings uncover the novel correlations of THOC with TNBC stemness and therapeutic resistance, proposing alternative therapeutic strategies against relapsed TNBC.

The Effect of Breast Cancer Subtype on Symptom Improvement Following Palliative Radiotherapy for Bone Metastases

AIM

To assess the relationship between breast cancer subtypes and patient-reported outcomes (PRO) following palliative radiotherapy for bone metastases.

MATERIALS AND METHODS

Prospectively collected PRO for all breast cancer patients treated with palliative, bone metastasis-directed radiotherapy from 2013 to 2016 in the province of British Columbia were analysed. The PRO questionnaire scored pain severity, level of function and symptom frustration at baseline and at 3-4 weeks following palliative radiotherapy using a 12-point scale. The primary outcome was the rate of overall response (any improvement in score); the secondary outcome was the rate of complete improvement in PRO (final PRO score of 0). Multivariate logistic analysis was used to compare response rates between molecular subgroup approximations of luminal A (LumA), luminal B (LumB), HER2-enriched (HER2) and triple negative (TN), as defined by grade and immunohistochemical staining.

RESULTS

There were 376 patients who underwent 464 courses of palliative radiation for bone metastases. Subtypes included: 243 LumA, 146 LumB, 46 HER2 and 29 TN. There were 216 multifraction radiotherapy courses (median dose 20 Gy) and 248 single-fraction radiotherapy courses (median dose 8 Gy). The overall response rate was 85% and the complete response rate was 25%. In comparison with LumA breast cancers, TN breast cancers were associated with a lower rate of overall response (69% versus 86%, P = 0.021) and a lower rate of complete response (10% versus 28.8%, P = 0.045) on multivariate analyses.

CONCLUSION

Patients with TN breast cancer have lower rates of pain, function and symptom frustration improvement following palliative radiation for bone metastases.

3-Bromopyruvate-mediated MCT1-dependent metabolic perturbation sensitizes triple negative breast cancer cells to ionizing radiation

BACKGROUND

Triple negative breast cancer (TNBC) poses a serious clinical challenge as it is an aggressive form of the disease that lacks estrogen receptor, progesterone receptor, and ERBB2 (formerly HER2) gene amplification, which limits the treatment options. The Warburg phenotype of upregulated glycolysis in the presence of oxygen has been shown to be prevalent in TNBC. Elevated glycolysis satisfies the energy requirements of cancer cells, contributes to resistance to treatment by maintaining redox homeostasis and generating nucleotide precursors required for cell proliferation and DNA repair. Expression of the monocarboxylate transporter 1 (MCT1), which is responsible for the bidirectional transport of lactate, correlates with an aggressive phenotype and poor outcome in several cancer types, including breast cancer. In this study, 3-bromopyruvate (3BP), a lactate/pyruvate analog, was used to selectively target TNBC cells that express MCT1.

METHODS

The cytotoxicity of 3BP was tested in MTT assays using human TNBC cell lines: BT20 (MCT1+/MCT4-), MDA-MB-23 (MCT1-/MCT4+), and BT20 in which MCT1 was knocked down (siMCT1-BT20). The metabolite profile of 3BP-treated and 3BP-untreated cells was investigated using LC-MS/MS. The extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) of BT20 and MDA-MB-231 cells treated with 3BP were measured using a Seahorse XF96 extracellular flux analyzer. The impact of ionizing radiation on cell survival, alone or in combination with 3BP pre-treatment, was evaluated using clonogenic assays.

RESULTS

Metabolomic analyses showed that 3BP causes inhibition of glycolysis, disturbance of redox homeostasis, decreased nucleotide synthesis, and was accompanied by a reduction in medium acidification. In addition, 3BP potentiated the cytotoxic effect of ionizing radiation, a treatment that is frequently used in the management of TNBC.

CONCLUSIONS

Overall, MCT1-mediated metabolic perturbation in combination with radiotherapy is shown to be a promising strategy for the treatment of glycolytic tumors such as TNBC, overcoming the selectivity challenges of targeting glycolysis with glucose analogs.

Caloric Restriction Impairs Regulatory T cells Within the Tumor Microenvironment After Radiation and Primes Effector T cells

Outcomes for triple negative breast cancer (TNBC) are poor and may be improved by increasing CD8+ tumor infiltrating lymphocytes (TIL) to augment antitumor immunity. Radiation (RT) can promote immunogenic cell death with increased antitumor T cell activity but also stimulates suppressive regulatory T cells (Tregs). Because metabolic alterations affect immune homeostasis and prior studies show caloric restriction (CR) combined with RT improves preclinical TNBC outcomes, we hypothesized that CR augments RT, in part, by altering intratumoral immunity. Using an in vivo model of TNBC, we treated mice with ad libitum (AL) diet, radiation, a CR diet, or CR + RT, and demonstrated an immune suppressive environment with a significant increase in CD4+ CD25+Foxp3+ Tregs after RT but not in CR-fed mice. CD8:Treg ratio in CR + RT TIL increased 4-fold compared with AL + RT mice. In vivo CD8 depletion was performed to assess the role of effector T cells in mitigating the effects of CR, and it was found that in mice undergoing CR, depletion of CD8 T cells resulted in increased tumor progression and decreased median survival compared with isotype control-treated mice. In addition, PD-1 expression on CD3+CD8+ T cells within the tumor microenvironment was significantly increased in CR + RT versus AL + RT treated mice as per immunofluorescence. Serum from breast cancer patients undergoing RT alone or CR and RT was collected pre- and postintervention, and a cytokine array demonstrated that patients treated with CR + RT had notable decreases in immunosuppressive cytokines such as IL-2Rγ, IL-10Rβ, and TGF-β2 and 3 compared with patients receiving RT alone. In conclusion, combining CR with RT decreases intratumoral Tregs, increases CD8:Treg, and increases PD-1 expression via a process dependent on CD8 T cells in a TNBC model. Breast cancer patients undergoing CR concurrently with RT also had significant reduction in immunosuppressive cytokine levels compared with those receiving RT alone.

Breast-Gynaecological & Immuno-Oncology International Cancer Conference (BGICC) Consensus and Recommendations for the Management of Triple-Negative Breast Cancer

Background: The management of patients with triple-negative breast cancer (TNBC) is challenging with several controversies and unmet needs. During the 12th Breast-Gynaecological & Immuno-oncology International Cancer Conference (BGICC) Egypt, 2020, a panel of 35 breast cancer experts from 13 countries voted on consensus guidelines for the clinical management of TNBC. The consensus was subsequently updated based on the most recent data evolved lately. Methods: A consensus conference approach adapted from the American Society of Clinical Oncology (ASCO) was utilized. The panellists voted anonymously on each question, and a consensus was achieved when ≥75% of voters selected an answer. The final consensus was later circulated to the panellists for critical revision of important intellectual content. Results and conclusion: These recommendations represent the available clinical evidence and expert opinion when evidence is scarce. The percentage of the consensus votes, levels of evidence and grades of recommendation are presented for each statement. The consensus covered all the aspects of TNBC management starting from defining TNBC to the management of metastatic disease and highlighted the rapidly evolving landscape in this field. Consensus was reached in 70% of the statements (35/50). In addition, areas of warranted research were identified to guide future prospective clinical trials.

Activation of the eIF2α/ATF4 axis drives triple-negative breast cancer radioresistance by promoting glutathione biosynthesis

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype. Radiotherapy is an effective option for the treatment of TNBC; however, acquired radioresistance is a major challenge to the modality. In this study, we show that the integrated stress response (ISR) is the most activated signaling pathway in radioresistant TNBC cells. The constitutive phosphorylation of eIF2α in radioresistant TNBC cells promotes the activation of ATF4 and elicits the transcription of genes implicated in glutathione biosynthesis, including GCLC, SLC7A11, and CTH, which increases the intracellular level of reduced glutathione (GSH) and the scavenging of reactive oxygen species (ROS) after irradiation (IR), leading to a radioresistant phenotype. The cascade is significantly up-regulated in human TNBC tissues and is associated with unfavorable survival in patients. Dephosphorylation of eIF2α increases IR-induced ROS accumulation in radioresistant TNBC cells by disrupting ATF4-mediated GSH biosynthesis and sensitizes them to IR in vitro and in vivo. These findings reveal ISR as a vital mechanism underlying TNBC radioresistance and propose the eIF2α/ATF4 axis as a novel therapeutic target for TNBC treatment.

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The eIF2α/ATF4 axis is constitutively activated in radioresistant TNBC.

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Phosphorylated eIF2α increases the expression of ATF4 and GCLC at the translational level in TNBC.

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The eIF2α/ATF4 axis activation causes radioresistance in TNBC by promoting GSH biosynthesis and ROS scavenging.

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ATF4 promotes GSH biosynthesis in radioresistant TNBC by triggering the expression of GCLC, CTH, and SLC7A11.

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Inhibition of the eIF2α/ATF4 axis can improve the sensitivity of TNBC to radiotherapy in vitro and in vivo.

Utility of post mastectomy radiotherapy among patients with T1/ T2 N1 disease: A retrospective cohort study

Background

Pakistan has the highest incidence of breast cancer among Asian Countries but there is insufficient representation of local data addressing breast cancer treatment and outcome. We sought to determine the role of post-mastectomy radiotherapy (PMRT) in T1- T2 breast cancer with 1–3 positive axillary lymph nodes.

Methods

Data was reviewed retrospectively of total 755 patients out of which 291 received PMRT and 464 did not from two large breast cancer centres.

Results

With a median follow up of 78 months, 4 (4.5%) patients developed loco regional recurrence (LRR) in the PMRT group while a substantial number 74 (24.4%) recurred in the non PMRT group (p = 0.000). Loco regional free survival rate (LRFS) and overall survival rate (OS) was significantly better for PMRT patients than non-PMRT patients (P = <0.000). Multivariate analysis identified young age, lymphovascular invasion, extra capsular extension, triple negative and ER/PR negative were independent prognostic factors affecting loco regional free survival (LRFS).

Conclusion

Disease recurrence is a substantial issue in 1–3 node group despite early stage, PMRT has an instrumental effect in improving LRFS and OS.

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Disease recurrence is a significant concern in post mastectomy patients with T1-T2 N1 disease.

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Post mastectomy radiotherapy (PMRT) has a substantial effect in reducing disease recurrence in this subset of patients.

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PMRT improves disease free survival rate (DFS) and overall survival rate (OS).

Personalization in Modern Radiation Oncology: Methods, Results and Pitfalls. Personalized Interventions and Breast Cancer

Breast cancer, the most frequent malignancy in women worldwide, is a heterogeneous group of diseases, characterized by distinct molecular aberrations. In precision medicine, radiation oncology for breast cancer aims at tailoring treatment according to tumor biology and each patient’s clinical features and genetics. Although systemic therapies are personalized according to molecular sub-type [i.e. endocrine therapy for receptor-positive disease and anti-human epidermal growth factor receptor 2 (HER2) therapy for HER2-positive disease] and multi-gene assays, personalized radiation therapy has yet to be adopted in the clinical setting. Currently, attempts are being made to identify prognostic and/or predictive factors, biomarkers, signatures that could lead to personalized treatment in order to select appropriate patients who might, or might not, benefit from radiation therapy or whose radiation therapy might be escalated or de-escalated in dosages and volumes. This overview focuses on what has been achieved to date in personalized post-operative radiation therapy and individual patient radiosensitivity assessments by means of tumor sub-types and genetics.

Giant Fungated Locally Advanced Breast Carcinoma Responded to Hypofractionated Radiotherapy Combined with Apatinib: A Case Report and Literature Review

Locally advanced breast cancer (LABC) is frequently encountered in clinical practice. Primary systemic therapy is regarded as the cornerstone of LABC management to downstage the disease and enable surgery. However, multiple lines of systemic agents may fail to control tumor growth in a considerable number of patients, and few options remain available for such patients. Here, we present a case of triple-negative, right breast cancer that progressed aggressively despite 3 lines of standard chemotherapy. The patient suffered from severe skin ulceration, bleeding, pain, infection, and fungation. The small-molecular tyrosine kinase inhibitor (TKI) apatinib was initiated, which targets vascular endothelial growth factor receptor 2 (VEGFR2). The patient then underwent hypofractionated irradiation applied to the whole right breast at 40 Gy/8 f. The tumor responded dramatically to this combination, and a near-complete remission (CR) response was achieved 2 months after irradiation. Our case is novel and instructional and demonstrated the efficacy and safety of hypofractionated irradiation combined with antiangiogenesis for the treatment of intractable LABC, shedding light on this difficult situation. In the near future, large-scale clinical trials will be initiated to further explore this issue.

Predicting the Survival of Triple-Negative Breast Cancer in Different Stages: A SEER Population Based Research Referring to Clinicopathological Factors

To evaluate prognosis of breast cancer patients, a total of 16,618 TNBC patients from SEER database were involved. High grade, unmarried status, tumor site were the main factors reduced OS in stage I. Black race, unmarried, large tumor size, and nodes metastasis would make worse prognosis in stage II. Compared with stage II, race and marital status had no significant effect on the prognosis in stage III. In stage IV, married status significantly improved the OS and DSS. Surgery and chemotherapy improve survival time in all of stages. Clinicopathological status correlated with the prognosis of patients with differentially staged TNBC.

Biological subtype predicts locoregional recurrence after postmastectomy radiotherapy in Chinese breast cancer patients

Aim

To investigate the impact of biological subtypes in locoregional recurrence in Chinese breast cancer patients receiving postmastectomy radiotherapy (PMRT).

Methods and Materials

About 583 patients who received postmastectomy radiation between 2010 and 2012 were retrospectively analyzed. According to immunohistochemical staining profile, patients were classified into: Luminal A‐like, Luminal B‐like, HER2‐positive, and triple‐negative breast cancer (TNBC). Local and regional recurrence (LRR) cumulative incidences were calculated by competing risks methodology and the power of prognostic factors was examined by Gray's test and the test of Fine and Gray.

Results

The median follow‐up was 70.9 months. About 34 LRR events occurred. For Luminal A, Luminal B, HER2‐positive, and TNBC patients, the 5‐year LRR cumulative incidence rates were 1.57%, 4.09%, 10.74%, and 10.28%. Compared with Luminal A, HER2‐positive subtype and TNBC had a significant increased risk of LRR (HR was 5.034 and 5.188, respectively). In univariate analysis, predictive factors for higher LRR were HER2‐positive subtype (HR = 4.43, P < .05), TNBC (HR = 4.70, P < .05), and pN3 (HR = 5.83, P < .05). In the multivariate model, HER2‐positive subtype (HR = 5.034, P < .05), TNBC (HR = 5.188, P < .05), and pN3 (HR = 9.607, P < .01) were independent predictors of LRR. LRR without trastuzumab was similar to that of TNBC (without vs TNBC, 17.88% vs 10.28%, P > .05) in HER2‐positive subtype patients, while LRR with trastuzumab was approximate to Luminal A (with vs Luminal A, P > .05). Additionally, endocrine therapy also significantly reduced LRR incidence in the luminal subtype cohort (without vs with therapy, 6.25% vs 2.89%, HR = 0.365, P < .1).

Conclusions

Biological subtype was a prognostic factor of LRR in the PMRT setting among Chinese breast cancer patients.

Synergy between Non-Thermal Plasma with Radiation Therapy and Olaparib in a Panel of Breast Cancer Cell Lines

Cancer therapy has evolved to a more targeted approach and often involves drug combinations to achieve better response rates. Non-thermal plasma (NTP), a technology rapidly expanding its application in the medical field, is a near room temperature ionized gas capable of producing reactive species, and can induce cancer cell death both in vitro and in vivo. Here, we used proliferation assay to characterize the plasma sensitivity of fourteen breast cancer cell lines. These assays showed that all tested cell lines were sensitive to NTP. In addition, a good correlation was found comparing cell sensitivity to NTP and radiation therapy (RT), where cells that were sensitive to RT were also sensitive to plasma. Moreover, in some breast cancer cell lines, NTP and RT have a synergistic effect. Adding a dose of PARP-inhibitor olaparib to NTP treatment always increases the efficacy of the treatment. Olaparib also exhibits a synergistic effect with NTP, especially in triple negative breast cancer cells. Results presented here help elucidate the position of plasma use as a potential breast cancer treatment.

On-Demand Biodegradable Boron Nitride Nanoparticles for Treating Triple Negative Breast Cancer with Boron Neutron Capture Therapy

Compared with photon-induced binary cancer therapy, such as photothermal therapy (PTT) and photodynamic therapy (PDT), boron neutron capture therapy (BNCT) emerges as an alternative noninvasive treatment strategy that could overcome the shallow penetration of light. One key factor in performing successful BNCT is to accumulate a sufficient amount of B-10 (>20 ppm) within tumor cells, which has been a long-standing challenge for small-molecule-based boron drugs. Boron nitride nanoparticles (BNNPs) are promising boron carriers due to their high boron content and good biocompatibility, as certain types of BNNPs can undergo rapid degradation under physiological conditions. To design an on-demand degradable boron carrier, BNNPs were coated by a phase-transitioned lysozyme (PTL) that protects BNNPs from hydrolysis during blood circulation and can be readily removed by vitamin C after neutron capture therapy. According to PET imaging, the coated BNNPs exhibited high tumor boron accumulation while maintaining a good tumor to nontumor ratio. Tail-vein injections of vitamin C were followed by neutron irradiation, and BNNPs were found to be rapidly cleared from major organs according to ex vivo ICP-OES analysis. Compared with the control group, animals treated with BNCT showed suppression of tumor growth, while almost negligible side effect was observed. This strategy not only utilized the high boron content of BNNPs but also successfully performed an on-demand degradation of BNNPs to avoid the potential toxicity caused by the long-term accumulation of nanoparticles.

Downregulation of TMPRSS4 Enhances Triple-Negative Breast Cancer Cell Radiosensitivity Through Cell Cycle and Cell Apoptosis Process Impairment

Background:

Radioresistance remains a challenge for cancer radiotherapy. The present study aims to investigate the role of TMPRSS4 in triple negative breast cancer (TNBC) cell radiosensitivity.

Materials and Methods:

After transfection of MDA-MD-468 triple negative breast cancer cells line by using the lentivirus vector, the effect of TMPRSS4 down-regulation on TNBC radiosensitivity was evaluated by using cloning assay and CCK-8 assay. The CCK-8 assay was also used for performing cell proliferation analysis. Western blot was carried out to detect the expression of certain proteins related to cell cycle pathways (cyclin D1), cell apoptosis pathways (Bax, Bcl2, and Caspase3), DNA damage and DNA damage repair (TRF2, Ku80 , ˠH2AX) . The cell cycle and cell apoptosis were also investigated using flow cytometer analysis.

Results:

TMPRSS4 expression was down-regulated in MDA-MB-468 cells which enhanced MDA-MB-468 cells radiosensitivity. TMPRSS4 silencing also improved IR induced cell proliferation ability reduction and promoted cell arrested at G2/M phase mediated by 6 Gy IR associated with cyclin D1 expression inhibition. Moreover, TMPRSS4 inhibition enhanced TNBC apoptosis induced by 6 Gy IR following by over-expression of (Bax, Caspase3) and down-regulation of Bcl2 as the pro-apoptotic and anti-apoptotic proteins, respectively. Otherwise, TMPRSS4 down-regulation increases DNA damage induced by 6 Gy IR and delays DNA damage repair respectively illustrated by downregulation of TRF2 and permanent increase of Ku80 and ˠH2AX expression at 1 h and 10 h post-IR.

Conclusion:

Down-regulation of TMPRSS4 increases triple negative breast cancer cell radiosensitivity and the use of TMPRSS4 inhibitor can be encouraged for improving radiotherapy effectiveness in TNBC radioresistant patients.

T1-2N0M0 Triple-Negative Breast Cancer Treated With Breast-Conserving Therapy Has Better Survival Compared to Mastectomy: A SEER Population-Based Retrospective Analysis

BACKGROUND

For early-stage breast cancer, the two current mainstay treatments are breast-conserving therapy (BCT; lumpectomy followed by radiotherapy [RT] and BCT) and mastectomy. Generally, triple-negative breast cancer (TNBC) is more aggressive compared to hormone receptor-positive breast cancer. We sought to investigate the effect of BCT compared to mastectomy on overall survival (OS) and breast cancer-specific survival (BCSS) in T1-2N0M0 TNBC.

PATIENTS AND METHODS

A population-based retrospective analysis was performed using the Surveillance, Epidemiology, and End Results (SEER) database. Patients included in the analysis were divided into 3 groups according to surgical modality and RT: BCT, mastectomy alone, and mastectomy with RT. The survival end points were OS and BCSS, and survival analysis was performed by the Kaplan-Meier method and the log-rank test among treatment types.

RESULTS

A total of 14,910 female subjects with T1-2N0M0 TNBC diagnosed between 2010 and 2014 were included. A total of 7381 patients had BCT; 6967 had mastectomy alone, and 562 had mastectomy with RT. Patients treated with BCT had better OS (log-rank P < .05) and BCSS (log-rank P < .05) than those receiving mastectomy with or without RT. The 5-year OS was 88.6% for BCT, 83.0% for mastectomy alone, and 79.6% for mastectomy with RT. The 5-year BCSS was 94.3% for BCT, 93.3% for mastectomy alone, and 83.7% for mastectomy with RT.

CONCLUSION

In patients with T1-2N0M0 TNBC, BCT was associated with superior OS and BCSS compared to mastectomy with or without RT. After mastectomy, there was no evidence of survival benefit of RT.

Calcitriol Inhibits the Proliferation of Triple-Negative Breast Cancer Cells through a Mechanism Involving the Proinflammatory Cytokines IL-1β and TNF-α

Triple-negative breast cancer (TNBC) is one of the most aggressive tumors, with poor prognosis and high metastatic capacity. The aggressive behavior may involve inflammatory processes characterized by deregulation of molecules related to the immunological responses in which interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are involved. It is known that calcitriol, the active vitamin D metabolite, modulates the synthesis of immunological mediators; however, its role in the regulation of IL-1β and TNF-α in TNBC has been scarcely studied. In the present study, we showed that TNBC cell lines SUM-229PE and HCC1806 expressed vitamin D, IL-1β, and TNF-α receptors. Moreover, calcitriol, its analogue EB1089, IL-1β, and TNF-α inhibited cell proliferation. In addition, we showed that synthesis of both IL-1β and TNF-α was stimulated by calcitriol and its analogue. Interestingly, the antiproliferative activity of calcitriol was significantly abrogated when the cells were treated with anti-IL-1β receptor 1 (IL-1R1) and anti-TNF-α receptor type 1 (TNFR1) antibodies. Furthermore, the combination of calcitriol with TNF-α resulted in a greater antiproliferative effect than either agent alone, in the two TNBC cell lines and an estrogen receptor-positive cell line. In summary, this study demonstrated that calcitriol exerted its antiproliferative effects in part by inducing the synthesis of IL-1β and TNF-α through IL-1R1 and TNFR1, respectively, in TNBC cells, highlighting immunomodulatory and antiproliferative functions of calcitriol in TNBC tumors.

A common Chk1-dependent phenotype of DNA double-strand break suppression in two distinct radioresistant cancer types

PURPOSE

Triple-negative breast cancers (TNBC) are often resistant to treatment with ionizing radiation (IR). We sought to investigate whether pharmacologic inhibition of Chk1 kinase, which is commonly overexpressed in TNBC, preferentially sensitizes TNBC cells to IR.

METHODS

Ten breast cancer cell lines were screened with small molecule inhibitors against Chk1 and other kinases. Chk1 inhibition was also tested in isogenic KRAS mutant or wild-type cancer cells. Cellular radiosensitization was measured by short-term and clonogenic survival assays and by staining for the DNA double-strand break (DSB) marker γ-H2AX. Radiosensitization was also assessed in breast cancer biopsies using an ex vivo assay. Aurora B kinase-dependent mitosis-like chromatin condensation, a marker of radioresistance, was detected using a specific antibody against co-localized phosphorylation of serine 10 and trimethylation of lysine 9 on histone 3 (H3K9me3/S10p). Expression of CHEK1 and associated genes was evaluated in TNBC and lung adenocarcinoma.

RESULTS

Inhibition of Chk1 kinase preferentially radiosensitized TNBC cells in vitro and in patient biopsies. Interestingly, TNBC cells displayed lower numbers of IR-induced DSBs than non-TNBC cells, correlating with their observed radioresistance. We found that Chk1 suppressed IR-induced DSBs in these cells, which was dependent on H3K9me3/S10p-a chromatin mark previously found to indicate radioresistance in KRAS mutant cancers. Accordingly, the effects of Chk1 inhibition in TNBC were reproduced in KRAS mutant but not wild-type cells. We also observed co-expression of genes in this Chk1 chromatin pathway in TNBC and KRAS mutant lung cancers.

CONCLUSIONS

Chk1 promotes an unexpected, common phenotype of chromatin-dependent DSB suppression in radioresistant TNBC and KRAS mutant cancer cells, providing a direction for future investigations into overcoming the treatment resistance of TNBC.

Silencing of XRCC4 increases radiosensitivity of triple-negative breast cancer cells

Background: Radiotherapy is an important locoregional treatment, and its effect on triple-negative breast cancer (TNBC) needs to be enhanced. The aim of the present study was to investigate the potential effects of XRCC4 on radiosensitivity of TNBC. Methods: The RNAi technique was implemented to establish the TNBC stable cell line with XRCC4 knockdown. MTT assay was used to detect the effect of XRCC4 knockdown on cell proliferation. Western blot and immunohistochemistry assays were employed to identify protein expression. Colony assay was performed to detect the effect of XRCC4 knockdown on the colony formation ability of TNBC cells with radiation treatment. Comet assay was conducted to evaluate the influence of XRCC4 silencing on DNA repair activity in ionizing radiation. In addition, we performed a survival analysis based on data in TCGA database. Results: XRCC4 knockdown by lentivirus-mediated shRNA had no significant effect on proliferation of TNBC cells. Knockdown of XRCC4 could substantially increase the sensitivity of TNBC cells to ionizing radiation. The DNA damage level was detected to be increased in the XRCC4 knockdown group, indicating there was a significant repair delay in the XRCC4-deleted cells. Clinical sample analysis exhibited that there were various XRCC4 expression in different patients with TNBC. Moreover, survival analysis showed that high expression of XRCC4 was significantly associated with poor progression-free survival after radiotherapy in TNBC patients. Conclusion: Our findings suggest that XRCC4 knockdown sensitizes TNBC cells to ionizing radiation, and could be considered as a novel predictor of radiosensitivity and a promising target for TNBC.

Radiotherapy after surgery has significant survival benefits for patients with triple-negative breast cancer

Objectives

The value of adjuvant radiotherapy for triple‐negative breast cancer (TNBC) has been controversial recently. This study aims to clarify the influence of radiotherapy on the survival of TNBC patients after surgery based on a large population analysis.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was exploited to select eligible patients from 2010 to 2014. The categorical variables were examined by chi‐square tests. Breast cancer‐specific survival (BCSS) and overall survival (OS) were compared among patients who received or not received adjuvant radiotherapy after surgery by Kaplan‐Meier method with log‐rank test. Univariate and multivariate survival analysis of BCSS and OS were performed using the Cox proportional hazard model.

Results

Totally 22 802 patients were enrolled in this study, of which 10 905 patients received radiotherapy after surgery while 11 897 patients did not receive radiotherapy. Compared with those patients who did not receive radiotherapy, the radiation group had a larger proportion of tumor size <2.0 cm (45.8% vs 38.8%) and chemotherapy (82.5% vs 67.4%). The Kaplan‐Meier plots displayed that patients in the radiation group had better survival than the no radiation group in both BCSS and OS (P < 0.001, respectively). In univariate Cox analysis of BCSS, age 40‐60, married status, white and other race, chemotherapy, radiation, and surgery were associated with better survival (HR < 1, P < 0.05). Specifically, patients who received radiotherapy exhibited better BCSS (HR = 0.52, 95% CI = 0.48‐0.57, P < 0.001). After adjusting for confounding factors by multivariable Cox regression analysis, receipt of radiotherapy was still associated with improved BCSS (HR = 0.79, 95% CI = 0.72‐0.87, P < 0.001). Survival analysis of OS produced similar results. Generally, these data indicate that radiotherapy after surgery has significant survival benefits for the TNBC patients.

Conclusions

This study has confirmed the survival advantage of adjuvant radiotherapy for the TNBC patients. These findings may optimize the current individualized treatment decisions for this patient population.

Highly potent monomethyl auristatin E prodrug activated by caspase-3 for the chemoradiotherapy of triple-negative breast cancer

Despite the emergence of advanced therapeutics such as targeted therapy and immunotherapy in the modern oncology, cytotoxic chemotherapy still remains as the first-line treatment option in a wide range of cancers attributing to its potency. Many endeavors have been made to overcome the toxicity issues of cytotoxic chemotherapy by improving the specific delivery to the tumor, with active tumor targeting being one of the most popular approaches. However, such an approach has been challenged by the intratumor heterogeneity and the lack of valid molecular target in many types of cancer. Here, we introduce a novel albumin-binding prodrug MPD02 that could specifically deliver highly potent cytotoxin monomethyl auristatin E (MMAE) to the tumor as an important component of chemoradiotherapy for the treatment of triple-negative breast cancer (TNBC). MPD02 was synthesized by conjugating MMAE to the C-terminus of the KGDEVD peptide via self-eliminating linker and introducing a maleimide group to the Lys side chain of the peptide. MPD02 was able to bind albumin after administration via maleimide group for an extended circulation time and metabolized into MMAE in tumor-specific manner by reacting with the caspase-3 upregulated in tumor by radiotherapy, exerting a highly potent anticancer effect with good safety profile in two different TNBC xenograft models.

Macrophages Promote Circulating Tumor Cell-Mediated Local Recurrence following Radiotherapy in Immunosuppressed Patients

Although radiotherapy (RT) decreases the incidence of locoregional recurrence in breast cancer, patients with triple-negative breast cancer (TNBC) have increased risk of local recurrence following breast-conserving therapy. The relationship between RT and local recurrence is unknown. Here, we tested the hypothesis that recurrence in some instances is due to the attraction of circulating tumor cells to irradiated tissues. To evaluate the effect of absolute lymphocyte count on local recurrence after RT in patients with TNBC, we analyzed radiation effects on tumor and immune cell recruitment to tissues in an orthotopic breast cancer model. Recurrent patients exhibited a prolonged low absolute lymphocyte count when compared with nonrecurrent patients following RT. Recruitment of tumor cells to irradiated normal tissues was enhanced in the absence of CD8+ T cells. Macrophages (CD11b+F480+) preceded tumor cell infiltration and were recruited to tissues following RT. Tumor cell recruitment was mitigated by inhibiting macrophage infiltration using maraviroc, an FDA-approved CCR5 receptor antagonist. Our work poses the intriguing possibility that excessive macrophage infiltration in the absence of lymphocytes promotes local recurrence after RT. This combination thus defines a high-risk group of patients with TNBC.Significance: This study establishes the importance of macrophages in driving tumor cell recruitment to sites of local radiation therapy and suggests that this mechanism contributes to local recurrence in women with TNBC that are also immunosuppressed.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/15/4241/F1.large.jpg Cancer Res; 78(15); 4241-52. ©2018 AACR.

CAPER as a therapeutic target for triple negative breast cancer

Breast cancers (BCas) that lack expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) are referred to as triple negative breast cancers (TNBCs) and have the poorest clinical outcome. Once these aggressive tumors progress to distant organs, the median survival decreases to 12 months. With endocrine therapies being ineffective in this BCa subtype, highly toxic chemo- and radiation therapies are the only options. A better understanding of the functional role(s) of molecular targets contributing to TNBC progression could help in the design and development of new treatments that are more targeted with less toxicity. CAPER (Co-activator of AP-1 and ER) is a nuclear transcriptional co-activator that was recently involved in ER-positive BCa progression, however its role in hormone-independent cancers remains unknown. Our current report demonstrates that CAPER expression is upregulated in human TNBC specimens compared to normal breast tissue and that its selective downregulation through a lentiviral-mediated shRNA knockdown approach resulted in decreased cell numbers in MDA-MB-231 and BT549 TNBC cell lines without affecting the growth of non-tumorigenic cell line MCF-10A. Concordant with these observations, CAPER knockdown was also associated with a decrease in DNA repair proteins leading to a marked increase in apoptosis, through caspase-3/7 activation without any changes in cell cycle. Collectively, we propose CAPER as an important signaling molecule in the development of TNBC linked to DNA repair mechanisms, which could lead to new therapeutic modalities for the treatment of this aggressive cancer.

Tumor-suppressing miR-141 gene complex-loaded tissue-adhesive glue for the locoregional treatment of hepatocellular carcinoma

microRNAs (miRNAs) regulate gene expression post-transcriptionally and have been extensively tested as therapeutic molecules against several human diseases. In vivo delivery of miRNAs needs to satisfy the following conditions: safety, efficiency, and long-term therapeutic effectiveness. To satisfy these conditions, we developed a tissue-adhesive nucleotide-polymer complex (NPX-glue) for in vivo delivery of miRNAs to treat hepatocellular carcinoma (HCC). Methods: Polyallylamine (PAA), a cationic polymer, was mixed with tumor-suppressing miR-141 to form NPX and then mixed with partially oxidized alginate (OA) to form NPX-glue. Delivery efficiency of miR-141:NPX-glue was determined in cultured HCC cells and in an implanted HCC tumor model. In vivo tumor-suppressive effects of miR-141 on HCC were examined in mice upon intratumoral injection of miR-141:NPX-glue. Result: NPX-glue was generated by mixing of NPX with OA, which eliminated the inherent cytotoxic effect of NPX. NPX-glue led to the efficient delivery of miR-141 and plasmid to cultured cells and solid tumors in mice, where their expression was maintained for up to 30 days. Upon intratumoral injection of miR-141:NPX-glue, the growth of the tumors was dramatically retarded in comparison with the negative control, NCmiR:NPX-glue, (p < 0.05). Molecular examination proved miR-141:NPX-glue efficiently regulated the target genes including MAP4K4, TM4SF1, KEAP1, HDGF, and TIAM1 and finally induced apoptosis of cancer tissues. Conclusion: Here, we show that NPX-glue delivers therapeutic miR-141 to solid tumors in a safe, stable, and long-term manner and prove that locoregional treatment of HCC is possible using the NPX-glue system.

How shall we treat early triple-negative breast cancer (TNBC): from the current standard to upcoming immuno-molecular strategies

Triple-negative breast cancer (TNBC) is a long-lasting orphan disease in terms of little therapeutic progress during the past several decades and still the standard of care remains chemotherapy. Experimental discovery of molecular signatures including the ‘BRCAness’ highlighted the innate heterogeneity of TNBC, generating the diversity of TNBC phenotypes. As it contributes to enhancing genomic instability, it has widened the therapeutic spectrum of TNBC. In particular, unusual sensitivity to DNA damaging agents was denoted in patients with BRCA deficiency, suggesting therapeutic benefit from platinum and poly(ADP-ribose) polymerase inhibitors. However, regardless of enriched chemosensitivity and immunogenicity, majority of patients with TNBC still suffer from dismal clinical outcomes including early relapse and metastatic spread. Therefore, efforts into more precise and personalised treatment are critical at this point. Accordingly, the advance of multiomics has revealed novel actionable targets including PI3K-Akt-mTOR and epidermal growth factor receptor signalling pathways, which might actively participate in modulating the chemosensitivity and immune system. Also, TNBC has long been considered a potential protagonist of immunotherapy in breast cancer, supported by abundant tumour-infiltrating lymphocytes and heterogeneous tumour microenvironment. Despite that, earlier studies showed somewhat unsatisfactory results of monotherapy with immune-checkpoint inhibitors, consistently durable responses in responders were noteworthy. Based on these results, further combinatorial trials either with other chemotherapy or targeted agents are underway. Incorporating immune-molecular targets into combination as well as refining the standard chemotherapy might be the key to unlock the future of TNBC. In this review, we share the current and upcoming treatment options of TNBC in the framework of scientific and clinical data, especially focusing on early stage of TNBC.

The positive role of vitronectin in radiation induced lung toxicity: the in vitro and in vivo mechanism study

Background

Radiation-induced lung toxicity (RILT) is a severe complication of radiotherapy in patients with thoracic tumors. Through proteomics, we have previously identified vitronectin (VTN) as a potential biomarker for patients with lung toxicity of grade ≥ 2 radiation. Herein, we explored the molecular mechanism of VTN in the process of RILT.

Methods

In this study, lentivirus encoding for VTN and VTN-specific siRNA were constructed and transfected into the cultured fibroblasts and C57BL mice. Real-time PCR, western blot and ELISA were used to examine expression of collagens and several potential proteins involved in lung fibrosis. Hematoxylin–eosin and immunohistochemical staining were used to assess the fibrosis scores of lung tissue from mice received irradiation.

Results

The expression of VTN was up-regulated by irradiation. The change trend of collagens, TGF-β expression and p-ERK, p-AKT, and p-JNK expression levels were positively related with VTN mRNA level. Furthermore, overexpression of VTN significantly increased the expression level of α-SMA, as well as the degree of lung fibrosis in mice at 8 and 12 weeks post-irradiation. By contrast, siRNA VTN induced opposite results both in vitro and in vivo.

Conclusions

VTN played a positive role in the lung fibrosis of RILT, possibly through modulation of fibrosis regulatory pathways and up-regulating the expression levels of fibrosis-related genes. Taken together, all the results suggested that VTN had a novel therapeutic potential for the treatment of RILT.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1474-y) contains supplementary material, which is available to authorized users.