Iniparib plus chemotherapy in metastatic triple-negative breast cancer

Ixazomib in combination with carboplatin in pretreated women with advanced triple-negative breast cancer, a phase I/II trial of the AGMT (AGMT MBC-10 trial)

Background

Triple-negative breast cancer (TNBC) comprises a heterogeneous group of diseases which are generally associated with poor prognosis. Up to now, no targeted treatment beyond anti-VEGF therapy has been approved for TNBC and cytotoxic agents remain the mainstay of treatment. Ixazomib is a selective and reversible inhibitor of the proteasome, which has been mainly investigated in the treatment of multiple myeloma. In a preclinical study TNBC cells were treated with the first-generation proteasome inhibitor bortezomib in combination with cisplatin and synergistic efficacy was demonstrated. Clinical data are available for carboplatin plus bortezomib in metastatic ovarian and lung cancers showing remarkable antitumor activity and good tolerability (Mol Cancer 11:26 2012, J Thorac Oncol 4:87–92 2009, J Thorac Oncol 7:1032–1040, 2012). Based on this evidence, the phase I/II MBC-10 trial will evaluate the toxicity profile and efficacy of the second-generation proteasome inhibitor ixazomib in combination with carboplatin in patients with advanced TNBC.

Methods

Patients with metastatic TNBC pretreated with at least one prior line of chemotherapy for advanced disease with a confirmed disease progression and measurable disease according to RECIST criteria 1.1 are eligible for this study. Patients will receive ixazomib in combination with carboplatin on days 1, 8, and 15 in a 28-day cycle. The phase I part of this study utilizes an alternate dose escalation accelerated titration design. After establishing the maximum tolerated dose (MTD), the efficacy and safety of the combination will be further evaluated (phase II, including 41 evaluable patients). All patients will continue on study drugs until disease progression, unacceptable toxicity or discontinuation for any other reason. Primary endpoint of the phase II is overall response rate, secondary endpoints include progression-free survival, safety, and quality of life. This trial is open for patient enrollment since November 2016 in six Austrian cancer centers. Accrual is planned to be completed within 2 years.

Discussion

Based on preclinical and clinical findings an ixazomib and carboplatin combination is thought to be effective in metastatic TNBC patients. The MBC-10 trial is accompanied by a broad biomarker program investigating predictive biomarkers for treatment response and potential resistance mechanisms to the investigational drug combination.

Trial registration

EudraCT Number: 2016–001421-13 received on March 31, 2016, ClinicalTrials.gov Identifier: NCT02993094 first posted on December 15, 2016. This trial was registered prospectively.

Targeted and immuno-biology driven treatment strategies for triple-negative breast cancer: current knowledge and future perspectives

Introduction: Accounting for about 15% of breast cancer patients, triple-negative breast cancer (TNBC) is responsible for 25% of disease related deaths, more frequent distant spread and visceral metastasis. However, improving survival in TNBC failed and primary resistance, immunological ignorance and tumor heterogeneity limit clinical activity of novel therapies. In view of recent molecular, genetic and immunologic insights, this review aims to describe the current status of immunological and targeted treatments from a hypothesis driven perspective. Areas covered: Recent preclinical studies and ongoing clinical trials for immune directed and targeted treatments of TNBC are summarized, including immune-checkpoint blockade, resistance mechanisms, inhibition of poly (ADP-ribose) polymerase (PARP), combinatorial strategies as well as preclinical, hypothesis generating studies. Expert commentary: Sustained responses have been observed with immune-checkpoint blockade and PARP inhibitors demonstrated remarkable efficacy in germline BRCA mutated TNBC. In order to generate clinical success of many other, to date ineffective, targeted and immune therapies, the integration of multidimensional, large amounts of data, will be essential and likely accelerate treatment progress of TNBC.

LincRNA-RoR/miR-145 promote invasion and metastasis in triple-negative breast cancer via targeting MUC1

Triple-negative breast cancer (TNBC) was associated with high rates of cancer recurrence and metastasis and currently no available molecularly target. Accumulating evidences have established the importance of lincRNA-ROR as a marker of cancers. In order to better understand the mechanism of lincRNA-ROR in TNBC, we provided a novel molecular target into the regulatory invasion and metastasis in present research. We found that lincRNA-ROR was upregulated in TNBC cell lines and tissue samples. The aberrant expression of lincRNA-ROR was shown to increase invasion and metastasis in MDA-MB-231 and loss of function by siRNA reverse these process. Furthermore, lincRNA-ROR functions as a competing endogenous RNAs (ceRNA) which sponges miR-145 and therefore upregulate the expression of Mucin1 (MUC1). The expression of MUC1 impacted E-cadherin membrane localization. Together, MUC1 was a potential molecular target may help explain the role of lincRNA-ROR/miR-145 for invasion and metastasis in TNBC cell lines.

Trabectedin and olaparib in patients with advanced and non-resectable bone and soft-tissue sarcomas (TOMAS): an open-label, phase 1b study from the Italian Sarcoma Group

BACKGROUND

Trabectedin is an alkylating drug with a unique mechanism of action causing single-strand and double-strand DNA breaks that activate DNA damage-response pathways. Based on our preclinical data, we hypothesised that poly(ADP-ribose) polymerase 1 (PARP1) inhibitors might be an ideal partner of trabectedin and aimed to assess the safety, identify the recommended phase 2 dose, and explore preliminary signs of activity of trabectedin and olaparib combination treatment in patients with bone and soft-tissue sarcoma.

METHODS

We did an open-label, multicentre, phase 1b study, recruiting patients from the national Italian sarcoma network aged 18 years and older with histologically confirmed bone and soft-tissue sarcoma progressing after standard treatments with Eastern Cooperative Oncology Group performance status of 1 or less. In a classic 3 + 3 design, patients received a 24 h infusion of trabectedin on day 1 and olaparib orally twice a day in 21-day cycles across six dose levels (trabectedin 0·675-1·3 mg/m² every 3 weeks; olaparib 100-300 mg twice a day from day 1 to 21). Intermediate dose levels were permitted to improve safety and tolerability. The primary endpoint was determination of the recommended phase 2 dose (the maximum tolerated dose). Safety and antitumour activity were assessed in all patients who received at least one dose of the study drugs. We report the results of the dose-escalation and dose-expansion cohorts. The trial is still active but closed to enrolment, and follow-up for patients who completed treatment is ongoing. This trial is registered with ClinicalTrials.gov, number NCT02398058.

FINDINGS

Between Nov 17, 2014, and Jan 30, 2017, of 54 patients assessed for eligibility, we enrolled 50 patients: 28 patients in the dose-escalation cohort and 22 patients in the dose-expansion cohort. Patients received a median of four cycles of treatment (IQR 2-6; range 1-17 [the patients who received the highest number of cycles are still on treatment]) with a median follow-up of 10 months (IQR 5-23). Considering all dose levels, the most common grade 3-4 adverse events were lymphopenia (32 [64%] of 50 patients), neutropenia (31 [62%]), thrombocytopenia (14 [28%]), anaemia (13 [26%]), hypophosphataemia (20 [40%]), and alanine aminotransferase concentration increase (9 [18%]). No treatment-related life-threatening adverse events or deaths occurred. One (2%) patient interrupted treatment without progression without reporting any specific toxicity. Observed dose-limiting toxicities were thrombocytopenia, neutropenia for more than 7 days, and febrile neutropenia. We selected intermediate dose level 4b (trabectedin 1·1 mg/m² every 3 weeks plus olaparib 150 mg twice a day) as the recommended phase 2 dose. Seven (14%; 95% CI 6-27) of 50 patients achieved a partial response according to Response Evaluation Criteria In Solid Tumors 1.1.

INTERPRETATION

Trabectedin and olaparib in combination showed manageable toxicities at active dose levels for both drugs. Preliminary data on antitumour activity are encouraging. Two dedicated phase 2 studies are planned to assess activity of this combination in both ovarian cancer (EudraCT2018-000230-35) and soft-tissue sarcomas.

FUNDING

Italian Association for Cancer Research, Italian Sarcoma Group, Foundation for Research on Musculoskeletal and Rare Tumors, and Italian Ministry of Health.

Poly(ADP-ribose) polymerase-3 overexpression is associated with poor prognosis in patients with breast cancer following chemotherapy

Double strand breaks induced by genotoxic agents, if inappropriately repaired, will cause cell death or induce cancer. Poly(ADP-ribose) polymerase-3 (PARP-3) serves a role in double strand break repair, and may be involved in tumorigenesis. To the best of our knowledge, the role of PARP-3 in breast cancer has not yet been examined. In the present study, the expression of PARP-3 was investigated in 493 breast cancer samples and 54 tumor-adjacent control samples using tissue-microarray-based immunohistochemistry. PARP-3 expression was higher in breast cancer samples compared with control samples. PARP-3 overexpression was significantly associated with histological grade II–III (P=0.012). In addition, PARP-3 overexpression was significantly associated with shorter disease-free survival (DFS; P=0.027) time and exhibited a tendency toward shorter overall survival (OS; P=0.183) time in patients with breast cancer compared with patients with lower PARP-3 expression, particularly in BRCA1-positive patients (P=0.004 for disease-free survival and P=0.095 for OS). Multivariate Cox regression analysis indicated that PARP-3 was an independent prognostic factor in patients with breast cancer. Furthermore, it was revealed that PARP-3 overexpression was associated with shorter survival time in patients with cyclophosphamide/doxorubicin or epirubicin/5-fluorouracil (CAF/CEF) chemotherapy compared with low PARP-3 expression, but not in patients with CAF/CEF + docetaxel chemotherapy. The present study suggested that PARP-3 may be used as a biomarker for predicting the clinical outcome of patients receiving chemotherapy, and targeting PARP-3 may be a potential therapeutic strategy for the treatment of breast cancer.

Bioinspired Hybrid Protein Oxygen Nanocarrier Amplified Photodynamic Therapy for Eliciting Anti-tumor Immunity and Abscopal Effect

An ideal cancer therapeutic strategy is expected to possess potent ability to not only ablate primary tumors but also prevent distance metastasis and relapse. In this study, human serum albumin was hybridized with hemoglobin by intermolecular disulfide bonds to develop a hybrid protein oxygen nanocarrier with chlorine e6 encapsulated (C@HPOC) for oxygen self-sufficient photodynamic therapy (PDT). C@HPOC realized the tumor-targeted co-delivery of photosensitizer and oxygen, which remarkably relieved tumor hypoxia. C@HPOC was favorable for more efficient PDT and enhanced infiltration of CD8⁺ T cells in tumors. Moreover, oxygen-boosted PDT of C@HPOC induced immunogenic cell death, with the release of danger-associated molecular patterns to activate dendritic cells, T lymphocytes, and natural killer cells in vivo. Notably, C@HPOC-mediated immunogenic PDT could destroy primary tumors and effectively suppress distant tumors and lung metastasis in a metastatic triple-negative breast cancer model by evoking systemic anti-tumor immunity. This study provides a paradigm of oxygen-augmented immunogenic PDT for metastatic cancer treatment.

Prognostic value of immunohistochemically detected p53 in adjuvant chemotherapy-treated triple negative breast cancer

Mutations of the p53 gene are the most common genomic alterations associated with triple-negative breast cancer (TNBC) and are reported in 60-88% cases. Despite the high incidence of such mutations, there is no consensus about the clinical application of p53 detection in breast cancer management. This study investigates the prognostic value of immunohistochemically detected p53 in TNBC patients who received adjuvant chemotherapy. We reviewed the clinicopathologic features of 1088 TNBC patients who received curative surgery and adjuvant chemotherapy. Immunohistochemically, nuclear staining of >10% was defined as p53 "positive." Of the total 1088 TNBC patients, 709 (65.2%) had no lymph node metastasis (N0). Among the N0 patients, 408 (57.5%) were p53- positive (p53+), and 301 (42.5%) were p53- negative (p53-). p53 + tumors showed a tendency for better breast cancer-specific survival (BCSS, p = 0.052) and overall survival (OS, p = 0.079) compared to p53- tumors. In multivariate analysis, p53 + tumors showed significantly better BCSS (p53 + vs. p53-; HR 2.8, 95% confidence interval: 1.1-7.3, p = 0.034); however, in TNBC patients with lymph node metastasis, there was no correlation between p53 status, clinicopathologic characteristics, and survival. Consequently, in TNBC patients who received adjuvant chemotherapy, immunohistochemical p53 expression was associated with better BCSS in N0 patients.

Phase II Study of Iniparib with Concurrent Chemoradiation in Patients with Newly Diagnosed Glioblastoma

PURPOSE

Iniparib is a purported prodrug causing cell death through intracellular conversion to nitro radical ions. We assessed the efficacy and safety of iniparib with standard radiotherapy and temozolomide in patients with newly diagnosed glioblastoma (GBM).

PATIENTS AND METHODS

Adults meeting eligibility criteria were enrolled in this prospective, single-arm, open-label multi- institution phase II trial with median overall survival (mOS) compared with a historical control as the primary objective. A safety run-in component of radiotherapy + temozolomide + iniparib (n = 5) was followed by an efficacy study (n = 76) with the recommended phase II doses of iniparib (8.0 mg/kg i.v. twice/week with radiotherapy + daily temozolomide followed by 8.6 mg/kg i.v. twice/week with 5/28-day temozolomide).

RESULTS

The median age of the 81 evaluable participants was 58 years (63% male). Baseline KPS was ≥ 80% in 87% of participants. The mOS was 22 months [95% confidence interval (CI), 17-24] and the HR was 0.44 (95% CI, 0.35-0.55) per-person-year of follow-up. The 2- and 3-year survival rates were 38% and 25%, respectively. Treatment-related grade 3 adverse events (AEs) occurred in 27% of patients; 9 patients had AEs requiring drug discontinuation including infusion-related reaction, rash, gastritis, increased liver enzymes, and thrombocytopenia.

CONCLUSIONS

Iniparib is well tolerated with radiotherapy and temozolomide in patients with newly diagnosed GBM at up to 17.2 mg/kg weekly. The primary objective of improved mOS compared with a historical control was met, indicating potential antitumor activity of iniparib in this setting. Dosing optimization (frequency and sequence) is needed prior to additional efficacy studies.

Precision medicine based on tumorigenic signaling pathways for triple-negative breast cancer

As a clinically heterogeneous subtype of breast cancer, triple-negative breast cancer (TNBC) is associated with a poor clinical outcome and a high relapse rate. Conventional chemotherapy and radiotherapy are effective treatments for patients with TNBC. However, the prognosis of TNBC remains unsatisfactory. Therefore, a large volume of research has explored the molecular markers and oncogenic signaling pathways associated with TNBC, including the cell cycle, DNA damage response and androgen receptor (AR) signaling pathways, to identify more efficient targeted therapies. However, whether these predicted pathways are effective targets has yet to be confirmed. In the present review, potentially carcinogenic signaling pathways in TNBCs from previous reports were considered, and ultimately five tumorigenic signaling pathways were selected, specifically receptor tyrosine kinases and downstream signaling pathways, the epithelial-to-mesenchymal transition and associated pathways, the immunoregulatory tumor microenvironment, DNA damage repair pathways, and AR and coordinating pathways. The conclusions of the preclinical and clinical trials of each pathway were then consolidated. Although a number of signaling pathways in TNBC have been considered in preclinical and clinical trials, the aforementioned pathways account for the majority of the malignant behaviors of TNBC. Identifying the alterations to different carcinogenic signaling pathways and their association with the heterogeneity of TNBC may facilitate the development of optimal precision medical approaches for patients with TNBC, potentially improving the efficiency of anticancer therapy.

Progress in targeted therapy for breast cancer

Breast cancer is a multistep, multifactorial, and heterogeneous disease. Significant transformations have occurred in the systemic management of breast cancer in the past decade. Due to the further understanding of pathogenesis, scientists have found plenty of signaling pathways and correspondingly therapeutic targets in breast cancer, such as hormone receptor, human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), phosphoinositide-3-kinase (PI3K), v-akt murine thymoma viral oncogene homolog (AKT), mechanistic target of rapamycin (mTOR), cyclin-dependent kinase 4/6 (CDK4/6), poly (adenosine diphosphate-ribose) polymerase (PARP), and programmed death-1 (PD-1). Targeted therapy, which optimizes the accuracy of antitumor activity and minimizes toxicity to normal tissues, plays a crucial role in breast cancer treatment in the era of precision medicine. In this review, we aimed to summarize the latest developments in targeted therapy for breast cancer and discuss the existing problems.

Somatic mutation of the cohesin complex subunit confers therapeutic vulnerabilities in cancer

A synthetic lethality-based strategy has been developed to identify therapeutic targets in cancer harboring tumor-suppressor gene mutations, as exemplified by the effectiveness of poly ADP-ribose polymerase (PARP) inhibitors in BRCA1/2-mutated tumors. However, many synthetic lethal interactors are less reliable due to the fact that such genes usually do not perform fundamental or indispensable functions in the cell. Here, we developed an approach to identifying the "essential lethality" arising from these mutated/deleted essential genes, which are largely tolerated in cancer cells due to genetic redundancy. We uncovered the cohesion subunit SA1 as a putative synthetic-essential target in cancers carrying inactivating mutations of its paralog, SA2. In SA2-deficient Ewing sarcoma and bladder cancer, further depletion of SA1 profoundly and specifically suppressed cancer cell proliferation, survival, and tumorigenic potential. Mechanistically, inhibition of SA1 in the SA2-mutated cells led to premature chromatid separation, dramatic extension of mitotic duration, and consequently, lethal failure of cell division. More importantly, depletion of SA1 rendered those SA2-mutated cells more susceptible to DNA damage, especially double-strand breaks (DSBs), due to reduced functionality of DNA repair. Furthermore, inhibition of SA1 sensitized the SA2-deficient cancer cells to PARP inhibitors in vitro and in vivo, providing a potential therapeutic strategy for patients with SA2-deficient tumors.

Where Do We Stand on the Integration of PARP Inhibitors for the Treatment of Breast Cancer?

PURPOSE OF REVIEW

To provide an overview of the clinical development of poly(ADP-ribose) polymerase inhibitors (PARPi) in breast cancer to date and to review existing challenges and future research directions.

RECENT FINDINGS

We summarize the clinical development of PARPi in breast cancer from bench to bedside, and discuss the results of recent phase 3 trials in patients with metastatic breast cancer (MBC) and germline mutations in BRCA1/2 (gBRCAm). We will also provide an update regarding mechanisms of action and resistance to PARPi, and review clinical trials of PARPi as monotherapy or in combination regimens. PARPi are a novel treatment approach in persons with gBRCA1/2m-associated MBC. Going forward, the clinical applicability of these compounds outside the gBRCAm setting will be studied in greater detail. The identification of accurate predictive biomarkers of response is a research priority.

Application of the CRISPR/Cas9 System to Drug Resistance in Breast Cancer

Clinical evidence indicates that drug resistance is a great obstacle in breast cancer therapy. It renders the disease uncontrollable and causes high mortality. Multiple mechanisms contribute to the development of drug resistance, but the underlying cause is usually a shift in the genetic composition of tumor cells. It is increasingly feasible to engineer the genome with the clustered regularly interspaced short palindromic repeats (CRISPR)/associated (Cas)9 technology recently developed, which might be advantageous in overcoming drug resistance. This article discusses how the CRISPR/Cas9 system might revert resistance gene mutations and identify potential resistance targets in drug-resistant breast cancer. In addition, the challenges that impede the clinical applicability of this technology and highlight the CRISPR/Cas9 systems are presented. The CRISPR/Cas9 system is poised to play an important role in preventing drug resistance in breast cancer therapy and will become an essential tool for personalized medicine.

Emerging therapeutic modalities of PARP inhibitors in breast cancer

Inhibition of Poly (ADP-ribose) polymerase (PARP) has shown marked benefit for breast cancer with homologous recombination deficiency, whether driven by defects in BRCA1, BRCA2, or other pathway components. Since the initial approval of olaparib, a mostly investigated PARP inhibitor (PARPi), the clinical development of PARPi in breast cancer treatment has been a major emphasis. Researches in investigating platinum-PARPi combination use compared with platinum monotherapy demonstrated promising benefit in metastatic BRCA mutated breast cancer or TNBC, while no such superiority was observed in the neoadjuvant setting of TNBC. Moreover, the utility of PARP inhibition in BRCA1/2 mutated breast cancer with different platinum-free interval was investigated. There was a clear association between clinical benefit with PARPi and platinum sensitivity, whereas partial efficacy of PARPi still occurs in platinum-resistant patients. In addition, proof-of-principle studies of immunotherapy combined with PARPi in breast cancer have obtained promising results, indicating the potential benefit of the combination therapy in patients with breast cancer. These efforts, contributing to maximize the utility of PARPi, may drive a new era of this agent after its first routine use. In this review, we summarized the utility of combining platinum-PARPi in BRCA mutated breast cancer or TNBC compared with platinum monotherapy and provided promising prospects of PARPi as maintenance therapy in breast cancer, as well as providing a strong rationale for testing immunotherapy combined with PARPi in breast cancer to expand the clinical utility of PARPi.

Dendrosomal nanocurcumin and exogenous p53 can act synergistically to elicit anticancer effects on breast cancer cells

Triple-negative breast cancer (TNBC) constitutes an important histological subtype of breast cancer with a highly metastatic phenotype. The aim of the current study was to investigate the possible synergism between dendrosomal nanocurcumin (DNC) and exogenously delivered p53 in producing anticancer effects on a TNBC cell line. MTT assay was exploited to determine the viability of MDA-MB-231 cells against DNC and measure the impact of p53 overexpresssion on DNC-related cytotoxicity. Annexin-V/PI staining followed by flow cytometry and wound healing assay were used to evaluate the effects of DNC and exogenous p53, alone and in combination, on apoptosis induction and migratory capacity of MDA-MB-231 cells, respectively. Also, quantitative real-time PCR was applied to analyze the transcript levels of EMT- and metastasis-associated genes. Cell viability measurements demonstrated that DNC suppresses the proliferation of MDA-MB-231 cells in a time- and dose-dependent mode and exogenous p53 elevates the sensitivity of cells to DNC-mediated cytotoxic effects. Apoptosis and wound healing assays indicated that combination treatment with DNC and exogenous p53 leads to significantly increased apoptosis and decreased migration of breast cancer cells, compared with single treatment. The results of gene expression analysis highlighted the high potency of combination strategy to significantly reduce the expression of ZEB1 and BMI1 transcript levels. Altogether, our findings reveal that DNC and exogenous p53 act in a synergistic manner to elicit anticancer effects on MDA-MB-231 breast cancer cells. Therefore, our combination approach might be considered as a promising strategy for the development of new therapeutic modalities against breast cancer.

The role of PARP inhibition in triple-negative breast cancer: Unraveling the wide spectrum of synthetic lethality

Triple-negative breast cancer (TNBC) accounts for approximately 15-20% of all breast cancers and is characterized by a lack of immunohistochemical expression of estrogen receptors (ER), progesterone receptors (PR) and HER2. TNBC is associated with poor long-term outcomes compared with other breast cancer subtypes. Many of these tumors are also basal-like cancers which are characterized by an aggressive biological behavior with a distant recurrence peak observed early at 3 years following diagnosis. Furthermore, metastatic TNBC bears a dismal prognosis with an average survival of 12 months. Although the prevalence of genetic alterations among women with TNBC differs significantly by ethnicity, race and age, BRCA mutations (including both germline mutations and somatic genetic aberrations) are found in up to 20-25% of unselected patients and especially in those of the basal-like immunophenotype. Therefore, defects in the DNA repair pathway could represent a promising therapeutic target for this subgroup of TNBC patients. Poly(ADP-ribose) polymerase (PARP) inhibitors exploit this deficiency through synthetic lethality and have emerged as promising anticancer therapies, especially in BRCA1 or BRCA2 mutation carriers. Several PARP inhibitors are currently being evaluated in the adjuvant, neo-adjuvant, and metastatic setting for the treatment of breast cancer patients with a deficient homologous recombination pathway. In this article, we review the major molecular characteristics of TNBC, the mechanisms of homologous recombination, and the role of PARP inhibition as an emerging therapeutic strategy.

5-aminoisoquinoline improves renal function and fibrosis during recovery phase of cisplatin-induced acute kidney injury in rats

The aim of the present study is to analyze the effects of 5-aminoisoquinoline (5-AIQ), a poly(ADP-ribose) polymerase-1 (PARP1) inhibitor, over renal dysfunction and fibrosis during recovery phase of cisplatin (CisPt)-induced acute kidney injury (AKI) in rats. Male Wistar rats were distributed in three groups (n=8 each group): control, CisPt, and CisPt + 5-AIQ. Control and CisPt groups received a subcutaneous injection of either saline or 7 mg/kg CisPt, respectively. CisPt + 5-AIQ group received two intraperitoneal injections of 10 mg/kg 5-AIQ 2 h before and 24 h after CisPt treatment. Thirteen days after the treatment, rats were housed in metabolic cages and 24-h urine collection was made. At day 14, CisPt-treated rats showed increased diuresis, N-acetyl-β-d-glucosaminidase (NAG) excretion, glucosuria and sodium fractional excretion (NaFE), and decreased creatinine clearance (CrCl). 5-AIQ significantly increased CrCl and decreased NAG excretion, glucosuria, and NaFE. In plasma, CisPt increased sodium, urea, and creatinine concentrations, while 5-AIQ treatment decreased these variables to the levels of control group. 5-AIQ completely prevented the body weight loss evoked by CisPt treatment. CisPt also induced an increased renal expression of PAR polymer, α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), and collagen-IV. These variables were decreased in CisPt + 5-AIQ group. Tubular lesions and renal fibrosis were also decreased by 5-AIQ treatment. We conclude that inhibition of PARP1 with 5-AIQ can attenuate long-term nephrotoxic effects associated with the CisPt treatment, preventing renal dysfunction and body weight decrease and ameliorating tubular lesions and collagen deposition.

Olaparib for the treatment of breast cancer

INTRODUCTION

Mutations in BRCA1 and BRCA2 genes account for around 2-3% of breast cancer events and more than 10% of triple negative breast cancers. Olaparib (Lynparza®), an orally administered PARP inhibitor, demonstrated clinical benefit in a phase III trial for mutated BRCA-positive HER2 negative metastatic breast cancer. Areas covered: This review gives an overview of available preclinical and clinical data regarding olaparib, including its chemistry, mechanism of action, pharmacokinetics and pharmacodynamics, and evidence supporting antitumor efficacy and safety profile in breast cancer patients. Expert commentary: Olaparib improves progression-free survival in germline BRCA mutated HER2 negative metastatic breast cancer patients as compared to standard chemotherapy, with a manageable toxicity profile. Efficacy is of clinical relevance especially in the context of triple negative breast cancer. However, several aspects, such as sequencing or combination of these agents with other anticancer agents and identification of appropriate biomarkers, still need to be clearly defined.

Light-Activated Core-Shell Nanoparticles for Spatiotemporally Specific Treatment of Metastatic Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) tumors are heterogeneous, with mesenchymal-like cells at their core and fast proliferating cells on the periphery. It is desirable and beneficial to treat TNBC cells of different phenotypes with the most appropriate drugs. Here, we report a 78 nm, chlorin e6-, docetaxel-, and anti-Twist siRNA-containing polymeric nanoparticle (CDTN) with spatiotemporally specific activity when irradiated by light. Under conditions mimicking superficial tumor tissue with sufficient light input, TNBC cells are mainly killed by the photodynamic therapy (PDT) function of CDTNs. In contrast, under conditions mimicking deep tumor tissue with weak light input, PDT potentiates chemotherapy (CT) and gene therapy (GT) by facilitating the endolysosomal escape of CDTNs. Compared with free drugs, CDTNs improve the intratumoral exposure of docetaxel and anti-Twist siRNA by 2.5- and 2-fold, respectively. When combined with laser irradiation applied at the time of maximal intratumoral accumulation, the CDTNs significantly inhibit the growth of primary tumors and their lung metastasis (both >80%) by killing the peripheral cells, mainly through PDT and prohibiting the growth and metastasis of deep cells through PDT as enhanced CT and GT. On the contrary, dual-modality nanomedicine lacking CT, GT, or PDT showed fast primary tumor growth, poor metastasis control, or both, respectively. This study reveals the spatiotemporally specific mechanism of CDTNs in treating metastatic TNBC and highlights the importance of combined therapy in treating TNBC.

Enzalutamide for the Treatment of Androgen Receptor-Expressing Triple-Negative Breast Cancer

Purpose Studies suggest that a subset of patients with triple-negative breast cancer (TNBC) have tumors that express the androgen receptor (AR) and may benefit from an AR inhibitor. This phase II study evaluated the antitumor activity and safety of enzalutamide in patients with locally advanced or metastatic AR-positive TNBC. Patients and Methods Tumors were tested for AR with an immunohistochemistry assay optimized for breast cancer; nuclear AR staining > 0% was considered positive. Patients received enzalutamide 160 mg once per day until disease progression. The primary end point was clinical benefit rate (CBR) at 16 weeks. Secondary end points included CBR at 24 weeks, progression-free survival, and safety. End points were analyzed in all enrolled patients (the intent-to-treat [ITT] population) and in patients with one or more postbaseline assessment whose tumor expressed ≥ 10% nuclear AR (the evaluable subgroup). Results Of 118 patients enrolled, 78 were evaluable. CBR at 16 weeks was 25% (95% CI, 17% to 33%) in the ITT population and 33% (95% CI, 23% to 45%) in the evaluable subgroup. Median progression-free survival was 2.9 months (95% CI, 1.9 to 3.7 months) in the ITT population and 3.3 months (95% CI, 1.9 to 4.1 months) in the evaluable subgroup. Median overall survival was 12.7 months (95% CI, 8.5 months to not yet reached) in the ITT population and 17.6 months (95% CI, 11.6 months to not yet reached) in the evaluable subgroup. Fatigue was the only treatment-related grade 3 or higher adverse event with an incidence of > 2%. Conclusion Enzalutamide demonstrated clinical activity and was well tolerated in patients with advanced AR-positive TNBC. Adverse events related to enzalutamide were consistent with its known safety profile. This study supports additional development of enzalutamide in advanced TNBC.

Frequent downregulation of LRRC26 by epigenetic alterations is involved in the malignant progression of triple-negative breast cancer

Triple-negative breast cancer (TNBC), defined as breast cancer lacking estrogen- and progesterone‑receptor expression and human epidermal growth factor receptor 2 (HER2) amplification, is a heterogeneous disease. RNA-sequencing analysis of 15 TNBC specimens and The Cancer Genome Atlas-TNBC dataset analysis identified the frequent downregulation of leucine-rich repeat-containing 26 (LRRC26), which negatively regulates nuclear factor-κB (NF-κB) signaling, in TNBC tissues. Quantitative polymerase chain reaction and bisulfite pyrosequencing analyses revealed that LRRC26 was frequently silenced in TNBC tissues and cell lines as a result of promoter methylation. LRRC26 expression was restored by 5-aza-2'-deoxycytidine (5'-aza-dC) treatment in HCC1937 TNBC cells, which lack LRRC26 expression. Notably, small interfering RNA-mediated knockdown of LRRC26 expression significantly enhanced the anchorage-independent growth, invasion and migration of HCC70 cells, whereas ectopic overexpression of LRRC26 in BT20 cells suppressed their invasion and migration. Conversely, neither knockdown nor overexpression of LRRC26 had an effect on cell viability in the absence of tumor necrosis factor-α (TNF-α) stimulation. Meanwhile, overexpression of LRRC26 caused the reduction of TNF-α-mediated NF-κB luciferase reporter activity, whereas depleting LRRC26 expression resulted in the upregulation of TNF-α-mediated NF-κB downstream genes [interleukin-6 (IL-6), IL-8 and C-X-C motif chemokine ligand-1]. Taken together, these findings demonstrate that LRRC26 is frequently downregulated in TNBC due to DNA methylation and that it suppresses the TNF-α-independent anchorage-independent growth, invasion and migration of TNBC cells. Loss of LRRC26 function may be a critical event in the aggressiveness of TNBC cells through a TNF-α/NF-κB-independent mechanism.

Analyses of repeated failures in cancer therapy for solid tumors: poor tumor-selective drug delivery, low therapeutic efficacy and unsustainable costs

For over six decades reductionist approaches to cancer chemotherapies including recent immunotherapy for solid tumors produced outcome failure-rates of 90% (±5) according to governmental agencies and industry. Despite tremendous public and private funding and initial enthusiasm about missile-therapy for site-specific cancers, molecular targeting drugs for specific enzymes such as kinases or inhibitors of growth factor receptors, the outcomes are very bleak and disappointing. Major scientific reasons for repeated failures of such therapeutic approaches are attributed to reductionist approaches to research and infinite numbers of genetic mutations in chaotic molecular environment of solid tumors that are bases of drug development. Safety and efficacy of candidate drugs tested in test tubes or experimental tumor models of rats or mice are usually evaluated and approved by FDA. Cost-benefit ratios of such ‘targeted’ therapies are also far from ideal as compared with antibiotics half a century ago. Such alarming records of failure of clinical outcomes, the increased publicity for specific vaccines (e.g., HPV or flu) targeting young and old populations, along with increasing rise of cancer incidence and death created huge and unsustainable cost to the public around the globe. This article discusses a closer scientific assessment of current cancer therapeutics and vaccines. We also present future logical approaches to cancer research and therapy and vaccines.

Male BRCA mutation carriers: clinical characteristics and cancer spectrum

Background

Mutations in BRCA1 and BRCA2 (BRCA1/2) genes are associated with an increased risk of breast and ovarian cancers in women. The cancer characteristics of men with BRCA1/2 mutations are less well studied. This study describes the unique cancer characteristics of male BRCA1/2 mutation carriers at our institution.

Methods

We performed a retrospective chart review on male patients who were seen between January 2004 and December 2014 and tested positive for a BRCA1/2 mutation. We evaluated clinical characteristics, pathology findings, treatment selection and survival.

Results

A total of 102 male patients were identified who tested positive for a BRCA1/2 deleterious mutation. Of these 102 patients, 33 (32%) had a diagnosis of cancer. Of these 33 patients with cancer, the majority (20 patients) were found to carry a BRCA2 mutation. Median age of cancer diagnosis was 65 years (Range: 35-75 years). Of the 33 patients diagnosed with cancer, 8 had two or more cancers, including 1 patient who had 4 cancers. Prostate cancer was the most commonly diagnosed cancer, seen in 13 patients, 11 of whom were BRCA2 positive. These cancers tended to have higher Gleason scores and elevated PSA levels. The majority of these prostate cancer patients were alive and disease free at a median follow-up of 7.4 years. Male breast cancer was the second most common cancer seen in 9 patients, all of whom were BRCA2 positive. The majority of these cancers were high grade, hormone receptor positive and associated with lymph node metastases. There were no breast cancer related deaths. Other cancers included bladder cancer, pancreatic cancer, melanoma and other skin cancers.

Conclusions

This study describes the cancer characteristics and outcomes of male BRCA1/2 mutation carriers. A third of male BRCA1/2 mutation carriers had a diagnosis of cancer. A significant number of patients (mostly BRCA2 mutation positive) developed multiple cancers, which may have important implications for cancer screening and prevention. Despite having high grade histology and advanced stage at diagnosis, male BRCA1/2 mutation carriers with breast and prostate cancer demonstrated a favorable 5-year survival.

miR-151-5p, targeting chromatin remodeler SMARCA5, as a marker for the BRCAness phenotype

In recent years, the assessment of biomarkers useful for “precision medicine” has been a hot topic in research. The involvement of microRNAs in the pathogenesis of breast cancer has been highly investigated with the aim of being able to molecularly stratify this highly heterogeneous disease. Our aim was to identify microRNAs targeting DNA repair machinery, through Affymetrix GeneChip miRNA Arrays, in a cohort of BRCA-related and sporadic breast cancers. Moreover, we analyzed microRNA expression taking into account our previous results on the expression of PARP1, because of its importance in targeted therapy. miR-361-5p and miR-151-5p were found to be overexpressed in PARP1-upregulating BRCA-germline mutated and sporadic breast tumors. Pathway enrichment analysis was performed to identify potential target genes to be analyzed in the validation step in an independent cohort. Our results confirmed the overexpression of miR-151-5p and, interestingly, its role in the targeting of SMARCA5, a chromatin remodeler. This result was also confirmed in vitro, both through luciferase assay and by analyzing endogenous levels of SMARCA5 in MCF-7 cell lines using miR-151-5p mimic and inhibitor. In conclusion, our data showed the possibility of considering the overexpression of PARP1 and miR-151-5p as biomarkers useful to correctly treat sporadic breast cancers, which eventually could be considered as BRCAness tumors, with PARP-inhibitors.

Mithramycin A suppresses basal triple-negative breast cancer cell survival partially via down-regulating Krüppel-like factor 5 transcription by Sp1

As the most malignant breast cancer subtype, triple-negative breast cancer (TNBC) does not have effective targeted therapies clinically to date. As a selective Sp1 inhibitor, Mithramycin A (MIT) has been reported to have anti-tumor activities in multiple cancers. However, the efficacy and the mechanism of MIT in breast cancer, especially TNBC, have not been studied. In this study, we demonstrated that MIT suppressed breast cancer cell survival in a dosage-dependent manner. Interestingly, TNBC cells were more sensitive to MIT than non-TNBC cells. MIT inhibited TNBC cell proliferation and promoted apoptosis in vitro in time- and dosage-dependent manners. MIT suppressed TNBC cell survival, at least partially, by transcriptionally down-regulating KLF5, an oncogenic transcription factor specifically expressed in basal TNBC. Finally, MIT suppressed TNBC cell growth in a xenograft mouse model. Taken together, our findings suggested that MIT inhibits basal TNBC via the Sp1/KLF5 axis and that MIT may be used for TNBC treatment.

Radiation-enhanced therapeutic targeting of galectin-1 enriched malignant stroma in triple negative breast cancer

Currently there are no FDA approved targeted therapies for Triple Negative Breast Cancer (TNBC). Ongoing clinical trials for TNBC have focused primarily on targeting the epithelial cancer cells. However, targeted delivery of cytotoxic payloads to the non-transformed tumor associated-endothelium can prove to be an alternate approach that is currently unexplored. The present study is supported by recent findings on elevated expression of stromal galectin-1 in clinical samples of TNBC and our ongoing findings on stromal targeting of radiation induced galectin-1 by the anginex-conjugated arsenic-cisplatin loaded liposomes using a novel murine tumor model. We demonstrate inhibition of tumor growth and metastasis in response to the multimodal nanotherapeutic strategy using a TNBC model with orthotopic tumors originating from 3D tumor tissue analogs (TTA) comprised of tumor cells, endothelial cells and fibroblasts. The ‘rigorous’ combined treatment regimen of radiation and targeted liposomes is also shown to be well tolerated. More importantly, the results presented provide a means to exploit clinically relevant radiation dose for concurrent receptor mediated enhanced delivery of chemotherapy while limiting overall toxicity. The proposed study is significant as it falls in line with developing combinatorial therapeutic approaches for stroma-directed tumor targeting using tumor models that have an appropriate representation of the TNBC microenvironment.

Histone Variant MacroH2A1 Plays an Isoform-Specific Role in Suppressing Epithelial-Mesenchymal Transition

Epithelial-Mesenchymal Transition (EMT) is a biological program that plays key roles in various developmental and pathological processes. Although much work has been done on signaling pathways and transcription factors regulating EMT, the epigenetic regulation of EMT remains not well understood. Histone variants have been recognized as a key group of epigenetic regulators. Among them, macroH2A1 is involved in stem cell reprogramming and cancer progression. We postulated that macroH2A1 may play a role in EMT, a process involving reprogramming of cellular states. In this study, we demonstrate that expression of macroH2A1 is dramatically reduced during EMT induction in immortalized human mammary epithelial cells (HMLE). Moreover, ectopic expression of the macroH2A1.1 isoform, but not macroH2A1.2, can suppress EMT induction and reduce the stem-like cell population in HMLE. Interestingly, macroH2A1.1 overexpression cannot revert stable mesenchymal cells back to the epithelial state, suggesting a stage-specific role of macroH2A1.1 in EMT. We further pinpointed that the function of macroH2A1.1 in EMT suppression is dependent on its ability to bind the NAD+ metabolite PAR, in agreement with the inability to suppress EMT by macroH2A1.2, which lacks the PAR binding domain. Thus, our work discovered a previously unrecognized isoform-specific function of macroH2A1 in regulating EMT induction.

Pharmacological activation of FOXO3 suppresses triple-negative breast cancer in vitro and in vivo

Triple-negative breast cancer (TNBC) is the most lethal form of breast cancer. Lacking effective therapeutic options hinders treatment of TNBC. Here, we show that bepridil (BPD) and trifluoperazine (TFP), which are FDA-approved drugs for treatment of schizophrenia and angina respectively, inhibit Akt-pS473 phosphorylation and promote FOXO3 nuclear localization and activation in TNBC cells. BPD and TFP inhibit survival and proliferation in TNBC cells and suppress the growth of TNBC tumors, whereas silencing FOXO3 reduces the BPD- and TFP-mediated suppression of survival in TNBC cells. While BPD and TFP decrease the expression of oncogenic c-Myc, KLF5, and dopamine receptor DRD2 in TNBC cells, silencing FOXO3 diminishes BPD- and TFP-mediated repression of the expression of these proteins in TNBC cells. Since c-Myc, KLF5, and DRD2 have been suggested to increase cancer stem cell-like populations in various tumors, reducing these proteins in response to BPD and TFP suggests a novel FOXO3-dependent mechanism underlying BPD- and TFP-induced apoptosis in TNBC cells.

Oxaliplatin-induced enteric neuronal loss and intestinal dysfunction is prevented by co-treatment with BGP-15

BACKGROUND AND PURPOSE

Gastrointestinal side effects of chemotherapy are an under-recognized clinical problem, leading to dose reduction, delays and cessation of treatment, presenting a constant challenge for efficient and tolerated anti-cancer treatment. We have found that oxaliplatin treatment results in intestinal dysfunction, oxidative stress and loss of enteric neurons. BGP-15 is a novel cytoprotective compound with potential HSP72 co-inducing and PARP inhibiting properties. In this study, we investigated the potential of BGP-15 to alleviate oxaliplatin-induced enteric neuropathy and intestinal dysfunction.

EXPERIMENTAL APPROACH

Balb/c mice received oxaliplatin (3 mg·kg^-1 ·day^-1 ) with and without BGP-15 (15 mg·kg^-1 ·day^-1 : i.p.) tri-weekly for 14 days. Gastrointestinal transit was analysed via in vivo X-ray imaging, before and after treatment. Colons were collected to assess ex vivo motility, neuronal mitochondrial superoxide and cytochrome c levels and for immunohistochemical analysis of myenteric neurons.

KEY RESULTS

Oxaliplatin-induced neuronal loss increased the proportion of neuronal NO synthase-immunoreactive neurons and increased levels of mitochondrial superoxide and cytochrome c in the myenteric plexus. These changes were correlated with an increase in PARP-2 immunoreactivity in the colonic mucosa and were attenuated by BGP-15 co-treatment. Significant delays in gastrointestinal transit, intestinal emptying and pellet formation, impaired colonic motor activity, reduced faecal water content and lack of weight gain associated with oxaliplatin treatment were restored to sham levels in mice co-treated with BGP-15.

CONCLUSION AND IMPLICATIONS

Our results showed that BGP-15 ameliorated oxidative stress, increased enteric neuronal survival and alleviated oxaliplatin-induced intestinal dysfunction, suggesting that BGP-15 may relieve the gastrointestinal side effects of chemotherapy.

PARP-1 inhibitors sensitize HNSCC cells to APR-246 by inactivation of thioredoxin reductase 1 (TrxR1) and promotion of ROS accumulation

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Mutations of TP53 may reach 70% - 85% in HNSCC patients without human papillomavirus (HPV) infection. Recurrence rate remains particularly high for HNSCC patients with mutations in the TP53 gene although patients are responsive to surgery, irradiation, and chemotherapy early in the treatment. p53-Reactivation and Induction of Massive Apoptosis-1 (PRIMA-1) and its methylated analogue PRIMA-1Met (also known as APR-246) are quinuclidine compounds that rescue the DNA-binding activity of mutant p53 (mut-p53) and restore the potential of wild-type p53. In the current report, we demonstrated that inhibition of poly (ADP-ribose) polymerase-1 (PARP-1) with 6(5H)-phenanthridinone (PHEN) and N-(6-Oxo-5,6-dihydrophenanthridin-2-yl)-(N, N-dimethylamino) acetamide hydrochloride (PJ34) sensitizes UMSCC1, UMSCC14, and UMSCC17A, three HNSCC cell lines to the treatment of APR-246. PHEN enhances APR-246-induced apoptosis, but not programmed necrosis or autophagic cell death in HNSCC cells. The PARP-1 inhibition-induced sensitization of HNSCC cells to APR-246 is independent of TP53 mutation. Instead, PARP-1 inhibition promotes APR-246-facilitated inactivation of thioredoxin reductase 1 (TrxR1), leading to ROS accumulation and DNA damage. Overexpression of TrxR1 or application of antioxidant N-acetyl-L-cysteine (NAC) depletes the ROS increase, reduces DNA damage, and decreases cell death triggered by APR-246/PHEN in HNSCC cells. Thus, we have characterized a new function of PARP-1 inhibitor in HNSCC cells by inactivation of TrxR1 and elevation of ROS and provide a novel therapeutic strategy for HNSCC by the combination of PARP-1 inhibitors and APR-246.

The exploration of contrasting pathways in Triple Negative Breast Cancer (TNBC)

Background

Triple Negative Breast Cancers (TNBCs) lack the appropriate targets for currently used breast cancer therapies, conferring an aggressive phenotype, more frequent relapse and poorer survival rates. The biological heterogeneity of TNBC complicates the clinical treatment further. We have explored and compared the biological pathways in TNBC and other subtypes of breast cancers, using an in silico approach and the hypothesis that two opposing effects (Yin and Yang) pathways in cancer cells determine the fate of cancer cells. Identifying breast subgroup specific components of these opposing pathways may aid in selecting potential therapeutic targets as well as further classifying the heterogeneous TNBC subtype.

Methods

Gene expression and patient clinical data from The Cancer Genome Atlas (TCGA) and the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) were used for this study. Gene Set Enrichment Analysis (GSEA) was used to identify the more active pathways in cancer (Yin) than in normal and the more active pathways in normal (Yang) than in cancer. The clustering analysis was performed to compare pathways of TNBC with other types of breast cancers. The association of pathway classified TNBC sub-groups to clinical outcomes was tested using Cox regression model.

Results

Among 4729 curated canonical pathways in GSEA database, 133 Yin pathways (FDR < 0.05) and 71 Yang pathways (p-value <0.05) were discovered in TNBC. The FOXM1 is the top Yin pathway while PPARα is the top Yang pathway in TNBC. The TNBC and other types of breast cancers showed different pathways enrichment significance profiles. Using top Yin and Yang pathways as classifier, the TNBC can be further subtyped into six sub-groups each having different clinical outcomes.

Conclusion

We first reported that the FOMX1 pathway is the most upregulated and the PPARα pathway is the most downregulated pathway in TNBC. These two pathways could be simultaneously targeted in further studies. Also the pathway classifier we performed in this study provided insight into the TNBC heterogeneity.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3939-4) contains supplementary material, which is available to authorized users.

Targeting DNA Repair

Genomic instability is a characteristic of most human cancers and plays critical roles in both cancer development and progression. There are various forms of genomic instability arising from many different pathways, such as DNA damage from endogenous and exogenous sources, centrosome amplification, telomere damage, and epigenetic modifications. DNA-repair pathways can enable tumor cells to survive DNA damage. The failure to respond to DNA damage is a characteristic associated with genomic instability. Understanding of genomic instability in cancer is still very limited, but the further understanding of the molecular mechanisms through which the DNA damage response (DDR) operates, in combination with the elucidation of the genetic interactions between DDR pathways and other cell pathways, will provide therapeutic opportunities for the personalized medicine of cancer.

Multi-gene Panel Testing in Breast Cancer Management

Hereditary predisposition accounts for approximately 10% of all breast cancers and is mostly associated with germline mutations in high-penetrance genes encoding for proteins participating in DNA repair through homologous recombination (BRCA1 and BRCA2). With the advent of massive parallel next-generation DNA sequencing, simultaneous analysis of multiple genes with a short turnaround time and at a low cost has become possible. The clinical validity and utility of multi-gene panel testing is getting better characterized as more data on the significance of moderate-penetrance genes are collected from large, cancer genetic testing studies. In this chapter, we attempt to provide a general guide for interpretation of panel gene testing in breast cancer and use of the information obtained for clinical decision-making.

Combined peripheral natural killer cell and circulating tumor cell enumeration enhance prognostic efficiency in patients with metastatic triple-negative breast cancer

Objective

Triple-negative breast cancer (TNBC) is a heterogeneous disease with poor prognosis. Circulating tumor cells (CTCs) are a promising predictor for breast cancer prognoses but their reliability regarding progression-free survival (PFS) is controversial. We aim to verify their predictive value in TNBC.

Methods

In present prospective cohort study, we used the Pep@MNPs method to enumerate CTCs in baseline blood samples from 75 patients with TNBC (taken at inclusion in this study) and analyzed correlations between CTC numbers and outcomes and other clinical parameters.

Results

Median PFS was 6.0 (range: 1.0-25.0) months for the entire cohort, in whom we found no correlations between baseline CTC status and initial tumor stage (P=0.167), tumor grade (P=0.783) or histological type (P=0.084). However, among those getting first-line treatment, baseline CTC status was positively correlated with ratio of peripheral natural killer (NK) cells (P=0.032), presence of lung metastasis (P=0.034) and number of visceral metastatic site (P=0.037). Baseline CTC status was predictive for PFS in first-line TNBC (P=0.033), but not for the cohort as a whole (P=0.118). This prognostic limitation of CTC could be ameliorated by combining CTC and NK cell enumeration (P=0.049).

Conclusions

Baseline CTC status was predictive of lung metastasis, peripheral NK cell ratio and PFS in TNBC patients undergoing first-line treatment. We have developed a combined CTC-NK enumeration strategy that allows us to predict PFS in TNBC without any preconditions.

Inexpensive NaX (X = I, Br, Cl) as a halogen donor in the practical Ag/Cu-mediated decarboxylative halogenation of aryl carboxylic acids under aerobic conditions

Versatile and practical Ag/Cu-mediated decarboxylative halogenation between readily available aryl carboxylic acids and abundant NaX (X = I, Br, Cl) has been achieved under aerobic conditions in moderate to good yields. The halodecarboxylation is shown to be an effective strategy for S-containing heteroaromatic carboxylic acid and benzoic acids with nitro, chloro and methoxyl substituents at the ortho position. A gram-scale reaction and a three-step procedure to synthesize iniparib have been performed to evaluate the practicality of this protocol. A preliminary mechanistic investigation indicates that Cu plays a vital role and a radical pathway is involved in the transformation.

Inhibition of growth and metastasis of triple-negative breast cancer targeted by Traditional Chinese Medicine Tubeimu in orthotopic mice models

Objective

Triple-negative breast cancer (TNBC) is highly invasive and metastatic, which is in urgent need of transformative therapeutics. Tubeimu (TBM), the rhizome of Bolbostemma paniculatum (Maxim.) Franquet, is one of the Chinese medicinal herbs used for breast diseases since the ancient times. The present study evaluated the efficacy, especially the anti-metastatic effects of the dichloromethane extract of Tubeimu (ETBM) on TNBC orthotopic mouse models and cell lines.

Methods

We applied real-time imaging on florescent orthotopic TNBC mice model and tested cell migration and invasion abilities with MDA-MB-231 cell line. Digital gene expression sequencing was performed and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis applied to explore the pathways influenced by ETBM. Moreover, quantitative real-time polymerase chain reactions (qRT-PCR) and Western blot were delivered to confirm the gene expression changes.

Results

ETBM exhibited noticeable control on tumor metastasis and growth of TNBC tumors with no obvious toxicity. In compliance with this, it also showed inhibition of cell migration and invasion in vitro. Its impact on the changed biological behavior in TNBC may be a result of decreased expression of integrin β1 (ITGβ1), integrin β8 (ITGβ8) and Rho GTPase activating protein 5 (ARHGAP5), which disabled the focal adhesion pathway and caused change in cell morphology.

Conclusions

This study reveals that ETBM has anti-metastatic effects on MDA-MB-231-GFP tumor and may lead to a new therapeutic agent for the integrative treatment of highly invasive TNBC.

Potential options for managing LOX+ ER- breast cancer patients

Overexpression of lysyl oxidase (LOX) is often observed in estrogen receptor negative (ER–) breast cancer patients with bone metastasis. In the present bioinformatics study, we observed that LOX is a prognostic factor for poor progression free survival in patients with ER– breast cancer. LOX overexpression was positively correlated with resistance to radiation, doxorubin and mitoxantrone, but negatively correlated with resistance to bisphosphonate, PARP1 inhibitors, cisplatin, trabectedin and gemcitabine. LOX overexpression was also associated with EMT and stemness of cancer cells, which leads to chemotherapeutic resistance and poor outcome in ER– patients. Although we suggest several therapeutic interventions that may help in the management of LOX+ ER– breast cancer patients, experiments to validate the function of LOX in ER– breast cancer are still needed.

Triple negative breast cancer: Emerging therapeutic modalities and novel combination therapies

Triple negative breast cancer (TNBC) is a complex and aggressive subtype of breast cancer which lacks oestrogen receptors, progesterone receptors and HER2 amplification, thereby making it difficult to target therapeutically. In addition, TNBC has the highest rates of metastatic disease and the poorest overall survival of all breast cancer subtypes. Resultantly, development of targeted therapies for TNBC is urgently needed. Recent efforts aimed at molecular characterisation of TNBCs have revealed various emerging therapeutic targets including PARP1, receptor and non-receptor tyrosine kinases, immune-checkpoints, androgen receptor and epigenetic proteins. Key successes include that of the PARP inhibitor, olaparib, which prolonged progression-free survival in a trial of BRCA-mutated breast cancer and for which clinical approval (in this setting) appears imminent. Nevertheless, the heterogeneity of TNBC has limited the clinical benefits of many trialled therapies in 'unselected' patients. Further, drug resistance develops following use of many targeted monotherapies due to upregulation of compensatory signalling pathways. In this review, we evaluate the current status of investigational targeted treatments and present evidence for the role of novel biomarkers and combination therapies in increasing response rates and circumventing drug-induced resistance. Additionally, we discuss promising novel targets in metastatic TNBC identified through preclinical and/or epidemiological studies.

Effect of antitumor treatments on triple-negative breast cancer patients: A PRISMA-compliant network meta-analysis of randomized controlled trials

BACKGROUND

Triple-negative breast cancer (TNBC) lacks the expression of the estrogen receptor, progesterone receptor, and receptor tyrosine-protein kinase erbB-2 (HER2/neu), which renders hormone-related endocrine and targeted therapy essentially futile.

OBJECTIVE

We performed a meta-analysis to assess the effects of antitumor regimens in the treatment of TNBC patients.

METHODS

We searched electronic databases, including PubMed, Embase, and the Cochrane Library, through January 2017 using the following keywords: "triple negative breast cancer," "TNBC," and "random*" without language restrictions. The major outcome in the present analysis was the overall response rate (ORR), and the secondary outcomes were progression-free survival (PFS) and overall survival (OS). A network meta-analysis and multilevel mixed-effects logistic regression were used to compare antitumor regimens.

RESULTS

We included 35 articles assessing a total of 8476 TNBC patients in our systematic review. The regimen of Bevacizumab, Carboplatin, and Paclitaxel (78.2%) was the most likely to improve the ORR in TNBC patients, followed by EndoTAG-1 and Paclitaxel (69.7%), Carboplatin and Paclitaxel (65.0%), and Bevacizumab and Paclitaxel (61.8%). In the patients without metastasis, the regimen of Bevacizumab, Carboplatin, and Paclitaxel (74.9%) remained the most likely to improve the ORR. We could not analyze the results for patients with metastasis or outcomes of PFS and OS because no >4 regimens formed a network. In the regression analysis, Bevacizumab (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.43-2.05; P < .001) and Carboplatin (OR, 2.07; 95% CI, 1.62-2.64; P < .001) correlated with superior ORR outcome, and Iniparib (OR, 1.51; 95% CI, 1.11-2.07; P = .009) correlated with superior OS outcome.

CONCLUSION

The regimen including Bevacizumab, Carboplatin, and Paclitaxel was the most likely to improve the ORR in TNBC patients and in advanced metastatic TNBC patients. The administration of Bevacizumab and Carboplatin provided greater benefit toward improved patient ORR.

The expression of APE1 in triple-negative breast cancer and its effect on drug sensitivity of olaparib

Triple-negative breast cancer is a kind of breast cancer with poor prognosis and special biological behavior, which lacked endocrine therapy and targeted therapy. We investigate the effect of human APE1 (apurinic/apyrimidyl endonuclease 1), a rate-limiting enzyme of base excision repair, on the prognosis in triple-negative breast cancer and drug sensitivity of olaparib. The expression of APE1 was detected by immunohistochemistry in the triple-negative breast cancer tissues and its effect on survival of triple-negative breast cancer patients was followed. To find whether APE1 effect the drug sensitivity in triple-negative breast cancer cells, the APE1-knockout HCC1937 cell line (triple-negative breast cancer cell line) was established by CRISPR/Cas9 system. Then, we use the wild-type and knockout one to test the drug sensitivity of olaparib. The expression of APE1 in triple-negative breast cancer tissues was significantly higher than that in the adjacent tissues (85.6% vs 14.4%) and its expression was related to tumor size (p < 0.05). We also found that it is an independent prognostic factor in patients with triple-negative breast cancer (overall survival, p = 0.01). In vitro assay, the half maximal inhibitory concentration of olaparib in HCC1937-APE1-KO was significantly increased (17.22 vs 91.85 μM) compared to the wild type. The growth curve showed that olaparib had a stronger lethality on HCC1937 compared to HCC1937- APE1-KO (p < 0.05 on day 3). HCC1937 resulted in more mitotic G2/M arrest and increased apoptosis rate after treatment with 40 μM of olaparib, while HCC1937-APE1-KO did not change significantly. When HCC1937 was treated with different concentrations of olaparib, it was found that APE1 expression decreased more significantly at 15 μM of olaparib was. In HCC1937-APE1-KO, the expression of endogenous poly (ADP-ribose) polymerase 1 was also less than that of HCC1937. These results suggested that the expression of APE1 was an important basis for the maintenance of poly (ADP-ribose) polymerase 1, and the deletion of APE1 may be related to the resistance of olaparib.

Current status of poly(ADP-ribose) polymerase inhibitors and future directions

Inhibitors of poly(ADP-ribose) polymerases (PARPs), which play a key role in DNA damage/repair pathways, have been developed as antitumor agents based on the concept of synthetic lethality. Synthetic lethality is the idea that cell death would be efficiently induced by simultaneous loss of function of plural key molecules, for example, by exposing tumor cells with inactivating gene mutation of BRCA-mediated DNA repair to chemically induced inhibition of PARPs. Indeed, three PARP inhibitors, olaparib, rucaparib and niraparib have already been approved in the US or Europe, mainly for the treatment of BRCA-mutant ovarian cancer. Clinical trials of various combinations of PARP inhibitors with cytotoxic or molecular-targeted agents are also underway. In particular, expanded applications of PARP inhibitors are anticipated following recent reports that defects in homologous recombination repair (HRR) are associated with mutations in repair genes other than BRCA1/BRCA2, such as ATM, ATR, PALB2, RAD51, CHEK1 and CHEK2, as well as with epigenetic loss of BRCA1 function through promoter methylation or overexpression of the BRCA2-interacting transcriptional repressor EMSY. Current topics of interest include selection of the best agent in each clinical context, identification of new treatment targets for HRR-proficient cases, and development of PARP inhibitor-based regimens that are less toxic and that prolong overall survival as well as progression-free survival. In addition, potential long-term side effects and suitable biomarkers for predicting efficacy and mechanisms of clinical resistance are in discussion. This review summarizes representative preclinical and clinical data for PARP inhibitors and discusses their potential for future applications to treat various malignancies.

Identification of differentially expressed genes regulated by molecular signature in breast cancer-associated fibroblasts by bioinformatics analysis

OBJECTIVE

Breast cancer is a severe risk to public health and has adequately convoluted pathogenesis. Therefore, the description of key molecular markers and pathways is of much importance for clarifying the molecular mechanism of breast cancer-associated fibroblasts initiation and progression. Breast cancer-associated fibroblasts gene expression dataset was downloaded from Gene Expression Omnibus database.

METHODS

A total of nine samples, including three normal fibroblasts, three granulin-stimulated fibroblasts and three cancer-associated fibroblasts samples, were used to identify differentially expressed genes (DEGs) between normal fibroblasts, granulin-stimulated fibroblasts and cancer-associated fibroblasts samples. The gene ontology (GO) and pathway enrichment analysis was performed, and protein-protein interaction (PPI) network of the DEGs was constructed by NetworkAnalyst software.

RESULTS

Totally, 190 DEGs were identified, including 66 up-regulated and 124 down-regulated genes. GO analysis results showed that up-regulated DEGs were significantly enriched in biological processes (BP), including cell-cell signalling and negative regulation of cell proliferation; molecular function (MF), including insulin-like growth factor II binding and insulin-like growth factor I binding; cellular component (CC), including insulin-like growth factor binding protein complex and integral component of plasma membrane; the down-regulated DEGs were significantly enriched in BP, including cell adhesion and extracellular matrix organization; MF, including N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase activity and calcium ion binding; CC, including extracellular space and extracellular matrix. WIKIPATHWAYS analysis showed the up-regulated DEGs were enriched in myometrial relaxation and contraction pathways. WIKIPATHWAYS, REACTOME, PID_NCI and KEGG pathway analysis showed the down-regulated DEGs were enriched endochondral ossification, TGF beta signalling pathway, integrin cell surface interactions, beta1 integrin cell surface interactions, malaria and glycosaminoglycan biosynthesis-chondroitin sulfate/dermatan sulphate. The top 5 up-regulated hub genes, CDKN2A, MME, PBX1, IGFBP3, and TFAP2C and top 5 down-regulated hub genes VCAM1, KRT18, TGM2, ACTA2, and STAMBP were identified from the PPI network, and subnetworks revealed these genes were involved in significant pathways, including myometrial relaxation and contraction pathways, integrin cell surface interactions, beta1 integrin cell surface interaction. Besides, the target hsa-mirs for DEGs were identified. hsa-mir-759, hsa-mir-4446-5p, hsa-mir-219a-1-3p and hsa-mir-26a-5p were important miRNAs in this study.

CONCLUSIONS

We pinpoint important key genes and pathways closely related with breast cancer-associated fibroblasts initiation and progression by a series of bioinformatics analysis on DEGs. These screened genes and pathways provided for a more detailed molecular mechanism underlying breast cancer-associated fibroblasts occurrence and progression, holding promise for acting as molecular markers and probable therapeutic targets.