Current approaches and future directions in the treatment of HER2-positive breast cancer

Therapeutic impact of 18F-FDG PET/CT for initial staging in patients with clinical stage I and IIA, HER2-positive, or triple-negative breast cancer

PURPOSE

While 18F-FDG PET/CT (FDG-PET/CT) is consensual for clinical stage ≥ IIB breast cancers (BC), its benefit for stage I or IIA HER2+ or triple-negative breast cancer (TNBC) patients lacks sufficient evidence. We reported a single-institution, retrospective study evaluating FDG-PET/CT impact on patient management and staging for stage I or IIA HER2+ or Triple-Negative BC.

METHODS

Patients who underwent FDG-PET/CT staging before any treatment between January 2015 and December 2020 at Oscar Lambret Center were included.

EXCLUSIONS

patients with symptoms or conventional imaging suggestive of metastatic dissemination, or with prior malignancies. Initial stage was determined from mammography, breast ultrasound, breast MRI, and clinical examination. Staging and therapeutic impact based on FDG-PET/CT findings collected, including intra- (modification of dose/site/strategy in a type of management previously indicated) and inter-modality (modification of planned treatment strategy) changes.

RESULTS

The cohort included 287 female patients with clinical stage I or IIA, HER2+ , or TNBC. Therapeutic impact observed for 18% of patients (n = 52), with 2% (n = 7) undergoing inter-modality change with omission of planned surgery. The impact on patient management was higher for stage IIA patients (20%, 47/237) than for stage I patients (10%, 5/50). Among stage IIA disease, changes in management were more important for T2N0 patients (22%, 44/205) than for T1N1 patients (9%, 3/32). While not statistically significant, trends suggest usefulness of FDG-PET/CT for T2N0 patients.

CONCLUSION

Considering substantial therapeutic implications, our study suggests the usefulness of FDG-PET/CT for patients with stage IIA, HER2-positive, or Triple-Negative BC with tumor size > 2 cm (T2N0).

An in-silico investigation and network pharmacology based approach to explore the anti-breast-cancer potential of Tecteria coadunata (Wall.) C. Chr

Uncontrolled cell proliferation is a common definition of cancer. After lung carcinoma, breast neoplasm is the second-most prevalent kind of cancer. The majority of breast cancer cells and healthy breast cells both have receptors for circulating oestrogen and progesterone. In order to promote the development and division of cancer cells, oestrogen and progesterone bind to the receptors and may collaborate with growth factors (such as oncogenes and mutant tumour suppressor genes). As per the literature, Tecteria coadunata (Wall.) C. Chr. has anticancer, antioxidant and anti-inflammatory potential. After the hydroalcoholic extraction of this rhizome, total of 200 phytochemicals were retrieved from HR-LCMS analysis. In this current study, Network pharmacology was carried out to explore the rationale of Tecteria coadunata (Wall.) C. Chr. by using different database using Cytoscape software. The network depicted the interaction of Bioactives with their targets and their association with several disease, especially breast cancer. Tecteria coadunata (Wall.) C. Chr. has offered new relationship with variety of genes and its applications in different types of breast cancers. Further Gene Ontology was carried out and it showed key targets were TP53, BRCA2, PGR and CHEK 2. Further Signalling pathways were also enriched. Flex-X software was used for molecular docking studies, and it verified that Dopaxanthin, Dantrolene and Orotidin shows the highest binding affinities with key targets. Additionally, Pharmacokinetic analysis revealed that all top three lead compounds which follows the Lipinski Rule (Rule of three) without interrupting the conditions of bioavailability with minimal toxicity.Communicated by Ramaswamy H. Sarma.

Trastuzumab-resistant breast cancer cells-derived tumor xenograft models exhibit distinct sensitivity to lapatinib treatment in vivo

BACKGROUND

Resistance to HER2-targeted therapies, including the monoclonal antibody trastuzumab and tyrosine kinase inhibitor lapatinib, frequently occurs and currently represents a significant clinical challenge in the management of HER2-positive breast cancer. We previously showed that the trastuzumab-resistant SKBR3-pool2 and BT474-HR20 sublines were refractory to lapatinib in vitro as compared to the parental SKBR3 and BT474 cells, respectively. The in vivo efficacy of lapatinib against trastuzumab-resistant breast cancer remained unclear.

RESULTS

In tumor xenograft models, both SKBR3-pool2- and BT474-HR20-derived tumors retained their resistance phenotype to trastuzumab; however, those tumors responded differently to the treatment with lapatinib. While lapatinib markedly suppressed growth of SKBR3-pool2-derived tumors, it slightly attenuated BT474-HR20 tumor growth. Immunohistochemistry analyses revealed that lapatinib neither affected the expression of HER3, nor altered the levels of phosphorylated HER3 and FOXO3a in vivo. Interestingly, lapatinib treatment significantly increased the levels of phosphorylated Akt and upregulated the expression of insulin receptor substrate-1 (IRS1) in the tumors-derived from BT474-HR20, but not SKBR3-pool2 cells.

CONCLUSIONS

Our data indicated that SKBR3-pool2-derived tumors were highly sensitive to lapatinib treatment, whereas BT474-HR20 tumors exhibited resistance to lapatinib. It seemed that the inefficacy of lapatinib against BT474-HR20 tumors in vivo was attributed to lapatinib-induced upregulation of IRS1 and activation of Akt. Thus, the tumor xenograft models-derived from SKBR3-pool2 and BT474-HR20 cells serve as an excellent in vivo system to test the efficacy of other HER2-targeted therapies and novel agents to overcome trastuzumab resistance against HER2-positive breast cancer.

Pharmacodynamic Modeling Identifies Synergistic Interaction Between Chloroquine and Trastuzumab in Refractory HER2- positive Breast Cancer Cells

BACKGROUND/AIM

Despite improvements in HER2-positive breast cancer (BC) patients' outcomes with trastuzumab, the occurrence of intrinsic or acquired resistance presents a clinical challenge. Here, we quantitatively assess the combinatorial effects of chloroquine, an autophagy inhibitor, with trastuzumab on JIMT-1 cells, a HER2-positive BC cell-line primarily resistant to trastuzumab.

MATERIALS AND METHODS

The temporal changes in JIMT-1 cellular viability were assessed using the CCK-8 kit, where JIMT-1 cells were exposed for 72-h to trastuzumab (0.007-17.19 μM) or chloroquine (5-50 μM) as single-agents, in combination (trastuzumab: 0.007-0.688 μM; chloroquine: 5-15 μM), or control (no drug). Concentration-response relationships were built for each treatment arm to determine drugs' concentrations inducing 50% of cell-killing (IC50). Cellular pharmacodynamic models were built to characterize the time-trajectory of JIMT-1 cellular viability under each treatment arm. The nature of trastuzumab and chloroquine interaction was quantified by estimating the interaction parameter (Ψ).

RESULTS

The IC50 were estimated at 19.7 and 24.4 μM for trastuzumab and chloroquine. The maximum killing effect was about thrice higher for chloroquine than trastuzumab (0.0405 vs. 0.0125 h^-1), validating chloroquine's superior anti-cancer effect on JIMT-1 cells compared to trastuzumab. The time-delay for chloroquine cell-killing was twice longer than that for trastuzumab (17.7 vs. 7 h), suggesting a chloroquine time-dependent anti-cancer effect. The Ψ was determined at 0.529 (Ψ<1), indicating a synergistic interaction.

CONCLUSION

This proof-of-concept study on JIMT-1 cells identified chloroquine and trastuzumab synergistic interaction, warranting further in vivo investigations.

Review of the status of neoadjuvant therapy in HER2-positive breast cancer

Purpose

The development of human epidermal growth factor receptor 2 (HER2)-directed therapies has revolutionized the treatment of HER2-positive breast cancer. The aim of this article is to review the continually evolving treatment strategies in the neoadjuvant setting of HER2-positive breast cancer, as well as the current challenges and future perspectives.

Methods

Searches were undertaken on PubMed and Clinicaltrials.gov for relevant publications and trials.

Findings

The current standard of care in high-risk HER2-positive breast cancer is to combine chemotherapy with dual anti-HER2 therapy, for a synergistic anti-tumor effect. We discuss the pivotal trials which led to the adoption of this approach, as well as the benefit of these neoadjuvant strategies for guiding appropriate adjuvant therapy. De-escalation strategies are currently being investigated to avoid over treatment, and aim to safely reduce chemotherapy, while optimizing HER2-targeted therapies. The development and validation of a reliable biomarker is essential to enable these de-escalation strategies and personalization of treatment. In addition, promising novel therapies are currently being explored to further improve outcomes in HER2-positive breast cancer.

The integrative bioinformatics approaches to predict the xanthohumol as anti-breast cancer molecule: Targeting cancer cells signaling PI3K and AKT kinase pathway

Background

Breast cancer is the most common type of cancer in women, and vast research is being conducted throughout the world for the treatment of this malignancy by natural products using various computational approaches. Xanthohumol, a prenylated flavonoid, is known for its anticancer activity; however, the mechanism behind its action is still in the preliminary stage.

Methods

The current study aimed to analyze the efficacy of xanthohumol compared to the currently available anticancer drugs targeting phosphoinositide-3-kinase (PI3K), serine/threonine kinase (AKT) receptors, and human epidermal growth factor receptor 2 (HER2) for breast cancer treatment through in silico analysis.

Results

The result revealed that the target compound showed significant binding affinity to targets within the PI3K, AKT, and HER2 signaling pathways with a binding energy of -7.5, -7.9, and -7.9 kcal/mol, respectively. Further prediction studies were then made concerning this compound's absorption, distribution, metabolism, and excretion (ADME) as well as drug-likeness properties, resulting in its oral bioavailability with only a single violation of Lipinski's rule of five.

Conclusions

The finding revealed the ability of xanthohumol to bind with multiple cancer cell signaling molecules including PI3K, AKT kinase, and HER2. The current novel study opened the door to advancing research into the management and treatment of breast cancer.

Perioperative HER2 targeted treatment in early stage HER2-positive breast cancer

Although human epidermal growth factor receptor 2 (HER2)-positive breast cancer was associated with poor prognosis, it has been changed after the development of trastuzumab. There has been great progress in perioperative HER2-targeting treatment, and investigations of several novel drugs and their combinations are ongoing. Adjuvant trastuzumab with or without pertuzumab for 1 year in combination with concomitant chemotherapy has become a standard treatment in high-risk node-negative tumors or node-positive HER2-positive early breast cancer patients without residual disease or who have not received neoadjuvant treatment. For low-risk HER2-positive early breast cancer patients, adjuvant paclitaxel and 1-year trastuzumab are possible alternatives. For residual disease after neoadjuvant treatment, adjuvant trastuzumab emtansine (T-DM1) for 14 cycles is a standard treatment. Non-anthracycline chemotherapy with dual anti-HER2 targeting of trastuzumab and pertuzumab represents one of the preferred neoadjuvant regimens to achieve higher pathologic complete response (pCR) rates and better clinical outcomes. Further research is needed to develop and validate potential biomarkers to predict pCR, which could help escalate or de-escalate anti-HER2 therapy. Trials incorporating novel agents such as T-DM1, trastuzumab deruxtecan (T-DXd), and immune checkpoint inhibitors and trying to de-escalate treatments in neoadjuvant setting are ongoing. In the future, tailored treatments such as no adjuvant therapy, various HER2-directed therapies alone with chemotherapy, combinations of various HER2-directed therapies and chemotherapy, addition of immune checkpoint inhibitors, and omission of surgery will be individualized in HER2-positive early breast cancer patients.

Galectin‐3 enhances trastuzumab resistance by regulating cancer malignancy and stemness in HER2 ‐positive breast cancer cells

Purpose

The aim of this study was to explore the role of galectin‐3 in human epidermal growth factor receptor 2 (HER2)‐positive breast cancer cells and the potential mechanism.

Methods

Kaplan–Meier (KM)‐plot and The Cancer Genome Atlas (TCGA) databases were used to study the role of galectin‐3 in the prognosis of HER2‐positive breast cancer. The effects of galectin‐3 on cell proliferation, migration, invasion, and colony formation ability in HER2‐positive breast cancer cells were examined. The relationship between galectin‐3 and important components in the HER2 pathways, including HER2, epidermal growth factor receptor (EGFR), protein kinase B (AKT), and phosphatase and tensin homolog (PTEN), was further studied. Lentivirus and CRISPR/Cas9 were used to construct stable cell lines. Cell counting kit‐8 (CCK‐8) and apoptosis assays were used to study the relationship between galectin‐3 and trastuzumab. The effect of galectin‐3 on cell stemness was studied by mammosphere formation assay. The effects of galectin‐3 on stemness biomarkers and the Notch1 pathway were examined. Tumorigenic models were used to evaluate the effects of galectin‐3 on tumorigenesis and the therapeutic effect of trastuzumab in vivo.

Results

HER2‐positive breast cancer patients with a high expression level of LGALS3 (the gene encoding galectin‐3) messenger RNA (mRNA) showed a poor prognosis. Galectin‐3 promoted cancer malignancy through phosphoinositide 3‐kinase (PI3K)/AKT signaling pathway activation and upregulated stemness by activating the Notch1 signaling pathway in HER2‐positive breast cancer cells. These two factors contributed to the enhancement of trastuzumab resistance in cells. Knockout of LGALS3 had a synergistic therapeutic effect with trastuzumab both in vitro and in vivo.

Conclusions

Galectin‐3 may represent a prognostic predictor and therapeutic target for HER2‐positive breast cancer.

Discovery of SPH5030, a Selective, Potent, and Irreversible Tyrosine Kinase Inhibitor for HER2-Amplified and HER2-Mutant Cancer Treatment

Small-molecule irreversible tyrosine kinase inhibitors as high potent agents have led to improvements in disease-free and overall survival in patients with HER2-amplified cancer. The approved irreversible HER2 inhibitors, neratinib and pyrotinib, both lack HER2 selectivity, leading to off-target adverse events in patients. The development of HER2 mutation during treatment also hampers the progress of the treatment. We used a molecular hybridization strategy for structural optimizations, in conjunction with in vitro and in vivo drug-like property screening, to obtain a clinical candidate SPH5030. Overall, SPH5030 showed excellent activities against four frequent kinds of HER2 mutants and high relative HER2 selectivity compared with neratinib and pyrotinib, good pharmacokinetic characteristics with desirable bioavailabilities, and significant in vivo antitumor efficacy in xenograft mouse models, especially in a HER2 mutation A775_G776insYVMA xenograft mouse model with its potency much higher than those of neratinib and pyrotinib.

A Bayesian approach to estimate the diffusion coefficient of Rhodamine 6G in breast cancer spheroids

Multicellular spheroids have emerged as a robust platform to model tumor growth and are widely used for studying drug sensitivity. Diffusion is the main mechanism for transporting nutrients and chemotherapeutic drugs into spheroids, since they are typically avascular. In this study, the Bayesian inference was used to solve the inverse problem of determining the light attenuation coefficient and diffusion coefficient of Rhodamine 6G (R6G) in breast cancer spheroids, as a mock drug for the tyrosine kinase inhibitor, Neratinib. Four types of breast cancer spheroids were formed and the diffusion coefficient was estimated assuming a linear relationship between the intensity and concentration. The mathematical model used for prediction is the solution to the diffusion problem in spherical coordinates, accounting for the light attenuation. The Gaussian likelihood was used to account for the error between the measurements and model predictions. The Markov Chain Monte Carlo algorithm (MCMC) was used to sample from the posterior. The posterior predictions for the diffusion and light attenuation coefficients were provided. The results indicate that the diffusion coefficient values do not significantly vary across a HER2+ breast cancer cell line as a function of transglutaminase 2 levels, even in the presence of fibroblast cells. However, we demonstrate that different diffusion coefficient values can be ascertained from tumorigenic compared to nontumorigenic spheroids and from nonmetastatic compared to post-metastatic breast cancer cells using this approach. We also report agreement between spheroid radius, attenuation coefficient, and subsequent diffusion coefficient to give evidence of cell packing in self-assembled spheroids. The methodology presented here will allow researchers to determine diffusion in spheroids to decouple transport and drug penetration changes from biological resistivity.

Selective therapeutic benefit of X-rays and inhibitors of EGFR, PI3K/mTOR, and Bcl-2 in breast, lung, and cervical cancer cells

Cancer continues to be a growing burden, especially in the resource limited regions of the world, and more effective and affordable therapies are highly desirable. In this study, the effect of X-ray irradiation and four inhibitors, viz. those against epidermal growth factor receptor (EGFR), phosphatidylinositol 3-kinase (PI3K), mammalian target of rapamycin (mTOR) and B-cell lymphoma 2 (Bcl-2) was evaluated in lung, breast, and cervical cancer cell lines, including normal cell lines to determine and compare the potential therapeutic benefit of these treatment modalities. A clonogenic survival assay was used to determine the radiosensitivity and cytotoxicity of inhibitors of EGFR, PI3K/mTOR, and Bcl-2 in the cell lines. From the data, the equivalent dose at which 50% of the cell populations were killed, for cancer and normal cells, was used to determine the relative cellular sensitivity to X-ray irradiation and inhibitor treatment. It was found that breast cancer cell lines were more sensitive to X-ray irradiation, whilst cervical and lung cancer cell lines were more sensitive to EGFR and PI3K/mTOR inhibitor therapy. These data suggest that patients with breast cancer possessing similar characteristics to MDA-MB-231 and MCF-7 cells may derive therapeutic benefit from X-ray irradiation, whilst EGFR and PI3K/mTOR inhibitor therapy may potentially benefit cancer patients possessing cancers similar to HeLa and A549 cells.

3-Epipachysamine B suppresses proliferation and induces apoptosis of breast cancer cell via PI3K/AKT/mTOR signaling pathway

3-Epipachysamine B is a natural steroidal alkaloid isolated from Pachysandra terminalis Sieb. et Zucc. (known locally as Kunxianqi). Kunxianqi contains numerous compounds with demonstrated activity against breast cancer (BRCA). However, it is unknown whether 3-epipachysamine B also has anti-BRCA efficacy. In the present study, we employed network pharmacology technology to search and find potential molecular targets of 3-epipachysamine B. We applied cell proliferation, apoptosis, and western blotting assays to test the predicted key targets and the effects of 3-epipachysamine B against BRCA. Network pharmacology disclosed 80 potential BRCA-related targets of 3-epipachysamine B and assigned them to 75 signaling pathways. Of these, the most highly enriched was the PI3K/AKT signaling pathway. PIK3R1, AKT1, and mTOR had high degrees and betweenness centrality in protein-protein interaction network and are associated with PI3K/AKT signaling. Molecular docking and molecular dynamics simulation indicated strong binding between 3-epipachysamine B and PIK3R1, AKT1, and mTOR. 3-Epipachysamine B repressed the proliferation and induced the apoptosis of BRCA cells, as well as downregulated P-AKT/AKT, P-mTOR/mTOR, and P-PI3K/PI3K in the cells. The PI3K inhibitor LY294002 augmented these changes. Hence, 3-epipachysamine could also prove effective as an anticancer agent in future animal tumor model and human clinical breast cancer trials. Successful validation results could lead to a safe and effective new breast cancer treatment that improves patient prognosis and quality of life.

TFEB, SIRT1, CARM1, Beclin-1 expression and PITX2 methylation in breast cancer chemoresistance: a retrospective study

BACKGROUND

Breast cancer chemoresistance is attributed to a wide variety of mechanisms, including autophagy. Transcription factor EB (TFEB) has been recently identified and characterized as one major regulator of autophagy and lysosomal genesis.

OBJECTIVE

This study aims to evaluate the prognostic impact of TFEB and its pathway in breast cancer chemoresistance.

METHODS

This retrospective study analyzes the expression of TFEB, CARM1, SIRT1, and Beclin-1 and the methylation of PITX2 in breast carcinoma. A group of breast cancer patients treated with chemotherapy, who relapsed within 12 months from treatment initiation, were compared to a sub-cohort of chemo-treated patients who did not recur within 12 months of follow-up. The expression of TFEB, CARM1, SIRT1, and Belcin-1 was analyzed using immunohistochemistry or RT-PCR on formalin-fixed paraffin-embedded samples. PITX2 methylation was tested with the diagnostic CE-marked kit Therascreen PITX2 RGQ PCR. In the final model, 136 cases of chemo-treated breast cancer were included.

RESULTS

A higher TFEB and Beclin-1 expression correlate with shorter survival in patients with chemo-treated invasive breast cancer (respectively HR 3.46, CI.95 1.27-9.47, p < 0.05 and 7.11, CI.95 2.54-19.9). TFEB, CARM1, and SIRT1 are positively correlated with Beclin-1. The protein expression of SIRT1 is significantly associated with TFEB and CARM1 so that a very low SIRT1 expression (lower than the first quartile of the H-score distribution) correlates with a low expression of TFEB and CARM1 and with longer survival. SIRT1 seems to have a lower H-score in the basal-like and HER2-enriched tumors than the luminal subtypes. Beclin-1 and TFEB seem to have a higher H-score in the basal-like and HER2-enriched tumors than the luminal subtypes. PITX2 methylation analysis was feasible only in 65% of the selected samples, but no significant differences between cases and controls were found, and there was also no correlation with the expression of the TFEB pathway.

CONCLUSIONS

TFEB, SIRT1, and Beclin-1 seem to have a potential prognostic significance in patients with chemo-treated breast cancer, likely because of their role in the regulation of autophagy. In addition, no correlation between TFEB and PITX2 methylation was found, likely because they perform two different roles within the autophagy process.

Potential Significance and Clinical Value Explorations of Calmin (CLMN) in Breast Invasive Carcinoma

Objective

Function of calmin (CLMN) was rarely reported in human diseases, especially in tumor. Present study initially assessed the significance of CLMN in breast invasive carcinoma (BRCA).

Methods

Expressions of CLMN containing mRNA and protein in BRCA was firstly assessed, and association of CLMN mRNA expression with clinical phenotypes of BRCA patients was analyzed as well. Prognostic value of CLMN in BRCA was subsequently predicted based on the clinical characteristics of patients. Finally, the potential biological function associated with CLMN involved in BRCA was revealed.

Results

(1) The mRNA expression of CLMN was lower in BRCA compared with that in normal patients (P<0.001). However, result of CLMN total protein expression was opposite (P<0.05). (2) The mRNA expression of CLMN was statistically associated with BRCA patient’s age, gender, PR status, ER status, histological type, tumor stage, copy number, and methylation level (all P<0.05). (3) Compared with low expression group, high expression of CLMN was conducive to the overall survival of BRCA patients (P=0.0011). Detailed, survival difference between CLMN high and low expression groups was observed in patients with stage 1 (P=0.0250), positive ER status (P=0.0042), negative HER status (P=0.0433), luminal A (P=0.0065), luminal B (P=0.0123) and positive lymph node status (P=0.0069). Pathway analysis suggested that CLMN mainly participated in cell cycle process (P<0.05) and exerted inhibition effect on the cell cycle involved in BRCA (P<0.05).

Conclusion

CLMN mRNA high expression prolonged the survival time of patients and caused a favorable prognosis. The positive function of CLMN in BRCA required further investigation in future work.

Disruption of FOXO3a-miRNA feedback inhibition of IGF2/IGF-1R/IRS1 signaling confers Herceptin resistance in HER2-positive breast cancer

Resistance to Herceptin represents a significant challenge for successful treatment of HER2-positive breast cancer. Here, we show that in Herceptin-sensitive cells, FOXO3a regulates specific miRNAs to control IGF2 and IRS1 expression, retaining basic IGF2/IGF-1R/IRS1 signaling. The basic activity maintains expression of PPP3CB, a subunit of the serine/threonine-protein phosphatase 2B, to restrict FOXO3a phosphorylation (p-FOXO3a), inducing IGF2- and IRS1-targeting miRNAs. However, in Herceptin-resistant cells, p-FOXO3a levels are elevated due to transcriptional suppression of PPP3CB, disrupting the negative feedback inhibition loop formed by FOXO3a and the miRNAs, thereby upregulating IGF2 and IRS1. Moreover, we detect significantly increased IGF2 in blood and IRS1 in the tumors of breast cancer patients with poor response to Herceptin-containing regimens. Collectively, we demonstrate that the IGF2/IGF-1R/IRS1 signaling is aberrantly activated in Herceptin-resistant breast cancer via disruption of the FOXO3a-miRNA negative feedback inhibition. Such insights provide avenues to identify predictive biomarkers and effective strategies overcoming Herceptin resistance.

Clinical evaluation of BCL-2/XL levels pre- and post- HER2-targeted therapy

Our previous pre-clinical work defined BCL-2 induction as a critical component of the adaptive response to lapatinib-mediated inhibition of HER2. To determine whether a similar BCL-2 upregulation occurs in lapatinib-treated patients, we evaluated gene expression within tumor biopsies, collected before and after lapatinib or trastuzumab treatment, from the TRIO-B-07 clinical trial (NCT#00769470). We detected BCL2 mRNA upregulation in both HER2+/ER- as well as HER2+/ER+ patient tumors treated with lapatinib or trastuzumab. To address whether mRNA expression correlated with protein expression, we evaluated pre- and post-treatment tumors for BCL-2 via immunohistochemistry. Despite BCL2 mRNA upregulation within HER2+/ER- tumors, BCL-2 protein levels were undetectable in most of the lapatinib- or trastuzumab-treated HER2+/ER- tumors. BCL-2 upregulation was evident within the majority of lapatinib-treated HER2+/ER+ tumors and was often coupled with increased ER expression and decreased proliferation. Comparable BCL-2 upregulation was not observed within the trastuzumab-treated HER2+/ER+ tumors. Together, these results provide clinical validation of the BCL-2 induction associated with the adaptive response to lapatinib and support evaluation of BCL-2 inhibitors within the context of lapatinib and other HER2-targeted receptor tyrosine kinase inhibitors.

Exploring the mechanism of Cremastra Appendiculata (SUANPANQI) against breast cancer by network pharmacology and molecular docking

BACKGROUND

SUANPANQI, the pseudo phosphorous stem of Cremastra appendiculata, is one of the most well-known traditional Chinese medicine, which has been shown to inhibit tumorigenesis in various human cancers. However, the underlying mechanism of SUANPANQI treatment against breast cancer (BRCA) remains unclear. In this study. we aim to investigate the bioactive compounds and mechanisms of SUANPANQI in the treatment of BRCA based on network pharmacology and molecular docking.

METHODS

The compounds were collected from previous research. SwissADME was used to screen bioactive compounds. The targets corresponding to SUANPANQI and BRCA were obtained using MalaCards and SwissTargetPrediction. SUANPANQI-related and BRCA-related targets were found and then overlapped to get intersections, which represented potential anti-BRCA targets of SUANPANQI. The Cytoscape software was used to construct bioactive compounds targeting the BRCA network. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the targets was extracted from the metascape database, then conducted using the Cluster Profiler package in R software. Protein-Protein interaction (PPI) network was constructed using the STRING online database and analyzed using Cytoscape software. Pivotal genes were screened using the topological analysis, survival analysis, and pathological stage analysis. Molecular docking analysis was used to verify whether the bioactive compounds had a definite affinity with the pivotal targets.

RESULTS

Sixty-five bioactive compounds of SUANPANQI were involved with 225 predicted BRCA targets. Then, a compound-target network and a PPI network were constructed. The GO analysis and KEGG enrichment analysis suggested that SUANPANQI worked against BRCA via PI3K-Akt, Ras, FoxO, Rap1, and ErbB signaling pathways, etc. After topological analysis, survival analysis, and pathological stage analysis of the SUANPANQI potential targets against BRCA, 6 pivotal target genes (AR, HSP90AA1, MMP9, PGR, PTGS2, TNF) that were highly responsible for the therapeutic effects of SUANPANQI against BRCA were obtained. Molecular docking results showed that 6 bioactive compounds of SUANPANQI had strong binding efficiency with the 6 pivotal genes.

CONCLUSIONS

The present study clarifies the mechanism of SUANPANQI against BRCA through multiple targets and pathways, and provides evidence to support its clinical use.

In-silico based identification of phytochemicals from Houttuynia cordata Thunb. as potential inhibitors for overexpressed HER2 and VEGFR2 cancer genes

Human epidermal growth factor receptor2 (HER2) and Vascular endothelial growth factor receptor2 (VEGFR2) - a tyrosine kinase receptors play a key role in breast and stomach cancers. The overexpression of HER2 and VEGFR2 genes increases the number of HER2 and VEGFR2 in the cell which initiates breast and stomach cancer respectively. The phytochemicals from traditional medicinal herb Houttuynia cordata Thunb. are reported to possess anti-inflammatory and anti-cancer potential. However, isolation of phytochemicals from this herb is fraught with uncertainly and time-consuming. Here, a molecular docking approach provides probable binding affinities between the receptors and phytochemicals (ligands) which initiate the first step of anticancer drug discovery and development. In the present study, In-silico docking approaches were used to identify the top-hit phytochemicals from H. cordata as potential inhibitors for overexpressed HER2 (breast) and VEGFR2 (stomach) cancer genes. A total of 100 biologically active phytochemicals from H. cordata were screened and docked against the ligand-binding pocket of HER2 and VEGFR2 kinase domains. Docking results revealed only a few phytochemicals (molecules) which appropriately fit into the ligand-binding pocket with higher binding affinity than the natural ATP ligand. A competitive docking was used to ascertain the top-hit phytochemicals that bind perfectly to the ATP ligand-binding pocket. Among the top-hit phytochemicals docked from H. cordata, the β-sitosterol and Quercetin showed highest binding affinity towards HER2 and VEGFR2 receptors using both hydrogen and hydrophobic interactions. This study confirmed β-sitosterol and Quercetin as potential drug candidates against breast and stomach cancer.Communicated by Ramaswamy H. Sarma.

Neuregulins in Neurodegenerative Diseases

Neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS), are typically characterized by progressive neuronal loss and neurological dysfunctions in the nervous system, affecting both memory and motor functions. Neuregulins (NRGs) belong to the epidermal growth factor (EGF)-like family of extracellular ligands and they play an important role in the development, maintenance, and repair of both the central nervous system (CNS) and peripheral nervous system (PNS) through the ErbB signaling pathway. They also regulate multiple intercellular signal transduction and participate in a wide range of biological processes, such as differentiation, migration, and myelination. In this review article, we summarized research on the changes and roles of NRGs in neurodegenerative diseases, especially in AD. We elaborated on the structural features of each NRG subtype and roles of NRG/ErbB signaling networks in neurodegenerative diseases. We also discussed the therapeutic potential of NRGs in the symptom remission of neurodegenerative diseases, which may offer hope for advancing related treatment.

HER2 splice variants in breast cancer: investigating their impact on diagnosis and treatment outcomes

Overexpression of the HER2 receptor occurs in approximately 20% of breast cancer patients. HER2 positivity is associated with poor prognosis and aggressive tumour phenotypes, which led to rapid progress in HER2 targeted therapeutics and diagnostic testing. Whilst these advances have greatly increased patients' chances of survival, resistance to HER2 targeted therapies, be that intrinsic or acquired, remains a problem. Different forms of the HER2 protein exist within tumours in tandem and can display altered biological activities. Interest in HER2 variants in breast cancer increased when links between resistance to anti-HER2 therapies and a particular variant, Δ16-HER2, were identified. Moreover, the P100 variant potentially reduces the efficacy of the anti-HER2 therapy trastuzumab. Another variant, Herstatin, exhibits 'auto-inhibitory' behaviour. More recently, new HER2 variants have been identified and are currently being assessed for their pro- and anti-cancer properties. It is important when directing the care of patients to consider HER2 variants collectively. This review considers HER2 variants in the context of the tumour environment where multiple variants are co-expressed at altered ratios. This study also provides an up to date account of the landscape of HER2 variants and links this to patterns of resistance against HER2 therapies and treatment plans.

A novel rabbit derived anti-HER2 antibody with pronounced therapeutic effectiveness on HER2-positive breast cancer cells in vitro and in humanized tumor mice (HTM)

Background

Antibody based cancer therapies have achieved convincing success rates combining enhanced tumor specificity and reduced side effects in patients. Trastuzumab that targets the human epidermal growth factor related receptor 2 (HER2) is one of the greatest success stories in this field. For decades, trastuzumab based treatment regimens are significantly improving the prognosis of HER2-positive breast cancer patients both in the metastatic and the (neo-) adjuvant setting. Nevertheless, ≥ 50% of trastuzumab treated patients experience de-novo or acquired resistance. Therefore, an enhanced anti-HER2 targeting with improved treatment efficiency is still aspired.

Methods

Here, we determined cellular and molecular mechanisms involved in the treatment of HER2-positive BC cells with a new rabbit derived HER2 specific chimeric monoclonal antibody called “B100″. We evaluated the B100 treatment efficiency of HER2-positive BC cells with different sensitivity to trastuzumab both in vitro and in the presence of a human immune system in humanized tumor mice.

Results

B100 not only efficiently blocks cell proliferation but more importantly induces apoptotic tumor cell death. Detailed in vitro analyses of B100 in comparison to trastuzumab (and pertuzumab) revealed equivalent HER2 internalization and recycling capacity, similar Fc receptor signaling, but different HER2 epitope recognition with high binding and treatment efficiency. In trastuzumab resistant SK-BR-3 based humanized tumor mice the B100 treatment eliminated the primary tumor but even more importantly eradicated metastasized tumor cells in lung, liver, brain, and bone marrow.

Conclusion

Overall, B100 demonstrated an enhanced anti-tumor activity both in vitro and in an enhanced preclinical HTM in vivo model compared to trastuzumab or pertuzumab. Thus, the use of B100 is a promising option to complement and to enhance established treatment regimens for HER2-positive (breast) cancer and to overcome trastuzumab resistance. Extended preclinical analyses using appropriate models and clinical investigations are warranted.

Therapeutic Monoclonal Antibodies in Clinical Practice against Cancer

The importance of monoclonal antibodies in oncology has increased drastically following the discovery of Milstein and Kohler. Since the first approval of the monoclonal antibody, i.e. Rituximab in 1997 by the FDA, there was a decline in further applications but this number has significantly increased over the last three decades for various therapeutic applications due to the lesser side effects in comparison to the traditional chemotherapy methods. Presently, numerous monoclonal antibodies have been approved and many are in queue for approval as a strong therapeutic agent for treating hematologic malignancies and solid tumors. The main target checkpoints for the monoclonal antibodies against cancer cells include EGFR, VEGF, CD and tyrosine kinase which are overexpressed in malignant cells. Other immune checkpoints like CTLA-4, PD-1 and PD-1 receptors targeted by the recently developed antibodies increase the capability of the immune system in destroying the cancerous cells. Here, in this review, the mechanism of action, uses and target points of the approved mAbs against cancer have been summarized.

Exploring Mechanism of Key Chinese Herbal Medicine on Breast Cancer by Data Mining and Network Pharmacology Methods

OBJECTIVE

To screen the key Chinese Herbal Medicines (KCHMs) against breast cancer by data mining, and analyze the potential mechanism of KCHMs using network pharmacology method.

METHODS

Clinical prescriptions consisted of CHMs for treating breast cancer were screened, and then Traditional Chinese Medicine Inheritance Support System (TCMISS) was applied to obtain the KCHMs. Subsequently, active ingredients and corresponding target genes of KCHMs were searched by Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database, and target genes of breast cancer were collected using OMIM and MalaCards. After that, the overlapping target genes of KCHMs and breast cancer were screened, and the protein-protein interaction (PPI) network was built. In addition, a network of "KCHMs-active ingredients-breast cancer-targets" was constructed by Cytoscape 3.7.1. Finally, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis were performed with Database for Annotation, Visualization and Integrated Discovery (DAVID) database to reveal the action mechanism of KCHMs.

RESULTS

A total of 7 KCHMs were identified, whose active ingredients include quercetin, luteolin, nobiletin, kaempferol, isorhamnetin, naringenin, and be-ta-sitosterol, etc. Based on protein-protein interaction analysis, core targets were ESR1, MYC, CCND1, EGFR, CASP3, ERBB2, etc. Several KEGG pathways (e.g, PI3K-Akt, p53, ErbB, and HIF-1 signaling pathways) were found.

CONCLUSION

Based on the combination of the data mining method and network pharmacology approach, the therapeutic effect of KCHMs on breast cancer may be realized by acting on target genes and signaling pathways related to the formation and progression of breast cancer.

Epithelial-mesenchymal transition status of circulating tumor cells in breast cancer and its clinical relevance

Objective: Circulating tumor cells (CTCs) play a critical role in cancer metastasis, but their prevalence and significance remain unclear. This study attempted to track the epithelial-mesenchymal transition (EMT) status of CTCs in breast cancer patients and investigate their clinical relevance. Methods: In this study, the established negFACS-IF:E/M platform was applied to isolate rare CTCs and characterize their EMT status in breast cancer. A total of 89 breast cancer patients were recruited, including stage 0-III (n = 60) and late stage (n = 29) cases. Results: Using the negFACS-IF:E/M platform, it was found that in human epidermal growth factor receptor 2 (HER2)+ patients, mesenchymal CTCs usually exhibited a high percentage of HER2+ cells. Stage IV breast cancer patients had considerably more CTCs than stage 0-III patients. Among stage 0-III breast cancers, the HER2 subtype included a significantly higher percentage of mesenchymal and biphenotypic (epithelial and mesenchymal) CTCs than the luminal A or B subtypes. Among stage IV patients, CTCs were predominantly epithelial in cases with local recurrence and were more mesenchymal in cases with distant metastasis. By applying a support vector machine (SVM) algorithm, the EMT status of CTCs could distinguish between breast cancer cases with metastasis/local recurrence and those without recurrence. Conclusions: The negFACS-IF:E/M platform provides a flexible and generally acceptable method for the highly sensitive and specific detection of CTCs and their EMT traits in breast cancer. This study demonstrated that the EMT status of CTCs had high clinical relevance in breast cancer, especially in predicting the distant metastasis or local recurrence of breast cancer.

Everolimus-containing therapy vs conventional therapy in the treatment of refractory breast cancer patients with PI3K/AKT/mTOR mutations: A retrospective study

Background

Previous case reports have shown the promising antitumor activity of everolimus in solid tumors containing molecular aberrations in PI3K/ATK/mTOR pathway, however, whether it is effective in patients with breast cancer remains unknown. Therefore, we conducted this retrospective cohort study to compare the efficacy of molecularly matched targeted therapy with everolimus to conventional therapy in refractory breast cancer patients harboring PI3K/ATK/mTOR pathway activating mutations.

Methods

Refractory metastatic breast cancer patients who have received molecular screening using next‐generation sequencing (NGS) between September 8, 2015 and October 30, 2017 in two sites were screened for this study. The primary outcome was progression‐free survival (PFS). The secondary outcomes were overall response rate (ORR), disease control rate (DCR), and safety profile.

Results

A total of 78 patients were screened for analysis, amongst all, 52 (66.7%) had at least one gene mutation in PI3K/AKT/mTOR pathway. The most common mutation fell in PIK3CA (76.9%, 40/52) with a mutational prevalence of 51.3%. Of the 32 patients who were eligible for efficacy analysis, patients in the everolimus group (n = 19) exhibited shorter PFS than those in the conventional group (n = 13) (median, 1.9 vs 6.1 months; HR, 3.6; 95% CI, 1.48‐8.81; P = .0005). ORR was 15.4% (2/13) in the everolimus group and 23.1% (3/13) in the conventional group (P = 1.000), and DCR was 30.8% (4/13) and 100% (13/13) for each group, respectively (P = .000). The incidence of grade 3‐5 adverse events was relatively higher in the conventional group (38.5%, 5/13) than that in the everolimus group (26.3%, 5/19).

Conclusions

Our findings suggested that everolimus might not be effective for cancer patients harboring mutations in PI3K/ATK/mTOR pathway and physicians should be cautious about its off‐label use in clinical practice.

Modelling the role of dual specificity phosphatases in herceptin resistant breast cancer cell lines

BACKGROUND

Breast cancer remains the most lethal type of cancer for women. A significant proportion of breast cancer cases are characterised by overexpression of the human epidermal growth factor receptor 2 protein (HER2). These cancers are commonly treated by Herceptin (Trastuzumab), but resistance to drug treatment frequently develops in tumour cells. Dual-specificity phosphatases (DUSPs) are thought to play a role in the mechanism of resistance, since some of them were reported to be overexpressed in tumours resistant to Herceptin.

RESULTS

We used a systems biology approach to investigate how DUSP overexpression could favour cell proliferation and to predict how this mechanism could be reversed by targeted inhibition of selected DUSPs. We measured the expression of 20 DUSP genes in two breast cancer cell lines following long-term (6 months) exposure to Herceptin, after confirming that these cells had become resistant to the drug. We constructed several Boolean models including specific substrates of each DUSP, and showed that our models correctly account for resistance when overexpressed DUSPs were kept activated. We then simulated inhibition of both individual and combinations of DUSPs, and determined conditions under which the resistance could be reversed.

CONCLUSIONS

These results show how a combination of experimental analysis and modelling help to understand cell survival mechanisms in breast cancer tumours, and crucially enable us to generate testable predictions potentially leading to new treatments of resistant tumours.

Inhibition of circular RNA CDR1as increases chemosensitivity of 5-FU-resistant BC cells through up-regulating miR-7

This study aims to explore the mechanism of Circular RNA CDR1as implicating in regulating 5-fluorouracil (5-FU) chemosensitivity in breast cancer (BC) by competitively inhibiting miR-7 to regulate CCNE1. Expressions of CDR1as and miR-7 in 5-FU-resistant BC cells were determined by RT-PCR. CCK-8, colony formation assay and flow cytometry were applied to measure half maximal inhibitory concentration (IC50), 5-Fu chemosensitivity and cell apoptosis. Western blot was used to detect the expressions of apoptosis-related factors. CDR1as was elevated while miR-7 was inhibited in 5-FU-resistant BC cells. Cells transfected with si-CDR1as or miR-7 mimic had decreased IC50 and colony formation rate, increased expressions of Bax/Bcl2 and cleaved-Caspase-3/Caspase-3, indicating inhibition of CDR1as and overexpression of miR-7 enhances the chemosensitity of 5-FU-resistant BC cells. Targetscan software indicates a binding site of CDR1as and miR-7 and that CCNE1 is a target gene of miR-7. miR-7 can gather CDR1as in BC cells and can inhibit CCNE1. In comparison to si-CDR1as group, CCNE1 was increased and chemosensitivity to 5-Fu was suppressed in si-CDR1as + miR-7 inhibitor group. When compared with miR-7 mimic group, CDR1as + miR-7 mimic group had increased CCNE1 and decreased chemosensitivity to 5-Fu. Nude mouse model of BC demonstrated that the growth of xenotransplanted tumour in si-CDR1as + miR-7 inhibitor group was faster than that in si-CDR1as group. The tumour growth in CDR1as + miR-7 mimic group was faster than that in miR-7 mimic group. CDR1as may regulate chemosensitivity of 5-FU-resistant BC cells by inhibiting miR-7 to regulate CCNE1.

Long non‑coding RNA FOXD2‑AS1/miR‑150‑5p/PFN2 axis regulates breast cancer malignancy and tumorigenesis

Breast cancer (BC) is a common cancer and leading cause of cancer‑associated mortality in women. Abnormal expression of long non‑coding RNA FOXD2 adjacent opposite strand RNA 1 (FOXD2‑AS1) was associated with the development of a number of tumors. However, whether FOXD2‑AS1 is dysregulated in BC and its underlying mechanisms remain unclear. In the present study, it was identified that FOXD2‑AS1 expression was upregulated in BC tissue, cell lines and sphere subpopulation. Additionally, the abnormal upregulation of FOXD2‑AS1 predicted poor prognosis in patients with BC. Furthermore, downregulation of FOXD2‑AS1 decreased cell proliferation, and migratory and invasive abilities in BC cells, and decreased the growth of transplanted tumors in vivo. Downregulation of FOXD2‑AS1 decreased the percentage of CD44 antigen+/signal transducer CD24- in breast cancer stem cell (BCSC) cells, and decreased the expression of numerous stem factors, including Nanog, octamer‑binding transcription factor 4 (Oct4), and sex determining region Y‑box 2 (SOX2), and inhibited the epithelial‑mesenchymal transition process. FOXD2‑AS1 was identified to be primarily located in the cytoplasm. Using bioinformatics analysis, a reporter gene assay and reverse transcription‑polymerase chain reaction assays, it was demonstrated that microRNA (miR)‑150‑5p was able to bind directly with the 3'‑untranslated region of FOXD2‑AS1 and PFN2 mRNA. miR‑150‑5p mimics decreased the cell proliferation, migration and invasion of BC cells. FOXD2‑AS1 knockdown significantly inhibited the miR‑150‑5p inhibitor‑induced increase in Nanog, Oct4 and SOX2 expression. The miR‑150‑5p inhibitor‑induced increase in N‑cadherin, and decrease in E‑cadherin and vimentin was inhibited by FOXD2‑AS1 knockdown. Profilin 2 (PFN2) expression was significantly upregulated in BC tissues. Additionally, the abnormal upregulation of PFN2 was associated with poor prognosis in patients with BC. FOXD2‑AS1 and PFN2 expression was positively correlated. Collectively, the present results demonstrated the role of the FOXD2‑AS1/miR‑150‑5p/PFN2 axis in the development of BC, and provides novel targets for the treatment of BC, and potential biomarkers for diagnosis and prognosis of BC.

Regulation of dual specificity phosphatases in breast cancer during initial treatment with Herceptin: a Boolean model analysis

Background

25% of breast cancer patients suffer from aggressive HER2-positive tumours that are characterised by overexpression of the HER2 protein or by its increased tyrosine kinase activity. Herceptin is a major drug used to treat HER2 positive breast cancer. Understanding the molecular events that occur when breast cancer cells are exposed to Herceptin is therefore of significant importance. Dual specificity phosphatases (DUSPs) are central regulators of cell signalling that function downstream of HER2, but their role in the cellular response to Herceptin is mostly unknown. This study aims to model the initial effects of Herceptin exposure on DUSPs in HER2-positive breast cancer cells using Boolean modelling.

Results

We experimentally measured expression time courses of 21 different DUSPs between 0 and 24 h following Herceptin treatment of human MDA-MB-453 HER2-positive breast cancer cells. We clustered these time courses into patterns of similar dynamics over time. In parallel, we built a series of Boolean models representing the known regulatory mechanisms of DUSPs and then demonstrated that the dynamics predicted by the models is in agreement with the experimental data. Furthermore, we used the models to predict regulatory mechanisms of DUSPs, where these mechanisms were partially known.

Conclusions

Boolean modelling is a powerful technique to investigate and understand signalling pathways. We obtained an understanding of different regulatory pathways in breast cancer and new insights on how these signalling pathways are activated. This method can be generalized to other drugs and longer time courses to better understand how resistance to drugs develops in cancer cells over time.

Electronic supplementary material

The online version of this article (10.1186/s12918-018-0534-5) contains supplementary material, which is available to authorized users.

SIRT7 depletion inhibits cell proliferation, migration, and increases drug sensitivity by activating p38MAPK in breast cancer cells

SIRT7 is a member of the sirtuin family of proteins that are known to be associated with tumor development. However, the functional roles and molecular mechanisms underlying the function of SIRT7 in breast cancer cell survival and tumor development remain unclear. Recent studies demonstrated that SIRT7 is upregulated in breast cancer cells and tissues. In the present study, we systematically explored the roles of SIRT7 in the growth of breast cancer cells and tumors both in vitro and in vivo. Our results showed that SIRT7 plays a major role in facilitating cell survival by promoting cell proliferation and inhibiting apoptosis. SIRT7 depletion significantly inhibited cell invasion and wound healing by blocking cell cycle progression and inducing cell apoptosis. Meanwhile, SIRT7 depletion can increase the sensitivity of breast cancer cells to doxorubicin (DOX). Xenograft model studies showed that stable silencing of SIRT7 inhibited tumor growth and enhanced tumor sensitivity to DOX. Further research revealed that p38MAPK is involved in SIRT7-mediated regulation of breast cancer cell proliferation and tumor growth. Taken together, our results showed that SIRT7 plays a critical role in breast cancer cell survival, migration, and tumor growth, and increased the efficiency of DOX treatment both in vitro and in vivo. Therefore, SIRT7 is a promising therapeutic target in breast cancer treatment.

MFAP5 promotes tumor progression and bone metastasis by regulating ERK/MMP signaling pathways in breast cancer

Breast cancer accounts for about 30% of all cancers in women, while approximately 70% breast cancer patients developed bone metastases throughout the course of their disease, highlighting the importance of exploring new therapeutic targets. Microfibrillar-associated protein 5 (MFAP5) is a component of extracellular elastic microfibril which has been confirmed to function in tissue development and cancer progression. But the role of MFAP5 in breast cancer remains unclear. The present study demonstrated that MFAP5 was up-regulated in breast cancers compared with that in normal breast tissues, and further increased in breast cancer bone metastasis. Functionally, MFAP5 overexpression accelerated breast cancer cell proliferation and migration, while an opposite effect was observed when MFAP5 was knocked down. In addition, up-regulation of MFAP5 increased the expression of MMP2 and MMP9 and activated the ERK signaling pathway. Conversely, inhibition of MFAP5 suppressed the expression of MMP2, MMP9, p-FAK, p-Erk1/2 and p-cJun. These findings may provide a better understanding about the mechanism of breast cancer and suggest that MFAP5 may be a potential prognostic biomarker and therapeutic target for breast cancer, especially for bone metastasis of breast cancer.

Clinical utility of RT-PCR in assessing HER 2 gene expression versus traditional IHC and FISH in breast cancer patients

BACKGROUND

IHC and FISH are used for categorizing HER 2 status in breast cancer at the protein and DNA level, respectively. HER 2 expression at the RNA level is quantitative, cheaper, easier to standardize and free from interobserver variation.

METHODS

115 consecutive patients were tested by IHC, FISH and RT-PCR (test cohort). Assuming FISH result to be the response variable, ROC curves for RT-PCR ratio were analyzed to label HER 2 negative, equivocal and positive cases as RT-PCR score 1, 2 and 3, respectively. Inter-relationships between RT-PCR, IHC and FISH were defined. 'Clinical benefit' of a test was defined as proportion of patients labeled unequivocally as HER 2 positive or negative. Population for 1 year was simulated constraint to previous reports of HER 2 positivity and IHC category distribution by a meta-analysis of previous studies that evaluated concordance between IHC and FISH to determine HER 2 status (simulation cohort). Four diagnostic pathways in the simulation cohort were defined-(1) initial IHC, followed by FISH (conventional pathway); (2) initial RT-PCR, followed by FISH; (3) initial IHC, followed by RT-PCR and then by FISH; (4) initial RT-PCR, followed by IHC and then by FISH. The clinical benefit of IHC and RT-PCR in the four pathways was analyzed and sensitivity analysis for incremental cost-effectiveness ratio and cost-benefit comapring RT-PCR against IHC, both as first-line tests and among those with IHC score 2 as a reflex second-line test was performed by the Monte Carlo technique.

FINDINGS

115 patients comprised the study population. While none with IHC score of 0 or 1 was FISH positive for HER 2, all cases with IHC score of 3 were FISH positive. 43 cases were assigned IHC score of 2. Thus, 72 patients benefited from the initial IHC testing [clinical benefit 62.6%], with the overall concordance between IHC and FISH being 100% for those with IHC score of 0, 1 and 3 (conclusive IHC categories). For RT-PCR with 100% concordance, 15.7% (115-97 = 18) patients would have benefited from RT-PCR testing if it was used as a first-line test. If RT-PCR would have been used as a second-line test among those with IHC score 2 (n = 43), then only 6 patients would have been assigned a conclusive RT-PCR category (category 1 or 3) translating to a clinical benefit of 14% (6/43) as a second-line test. As a second-line test it had 51% probability to prove more cost-effective than the conventional pathway, provided the cost of RT-PCR was 0.4 times the cost of IHC. Also in a three-step pathway, RT-PCR upfront would have 56% probability of higher cost-benefit provided the cost of RT-PCR was 0.1 times the cost of IHC.

CONCLUSION

RT-PCR results were found to be suboptimal to IHC in terms of discriminative ability and clinical benefit; thus, it is unlikely to replace IHC as a first-line test in the near future.

Research needs in breast cancer

New research questions emerge as medical needs continue to evolve and as we improve our understanding of cancer biology and treatment of malignancies. Although significant advances have been made in some areas of breast cancer research resulting in improvements in therapies and outcomes over the last few decades, other areas have not benefited to the same degree and we continue to have many gaps in our knowledge. This article summarizes the 12 short and medium-term clinical research needs in breast cancer deemed as priorities in 2016 by a panel of experts, in an attempt to focus and accelerate future research in the most needed areas: (i) de-escalate breast cancer therapies in early breast cancer without sacrificing outcomes; (ii) explore optimal adjuvant treatment durations; (iii) develop better tools and strategies to identify patients with genetic predisposition; (iv) improve care in young patients with breast cancer; (v) develop tools to speed up drug development in biomarker-defined populations; (vi) identify and validate targets that mediate resistance to chemotherapy, endocrine therapy and anti-HER2 therapies; (vii) evaluate the efficacy of local-regional treatments for metastatic disease; (viii) better define the optimal sequence of treatments in the metastatic setting; (ix) evaluate the clinical impact of intra-patient heterogeneity (intra-tumor, inter-tumor and inter-lesion heterogeneity); (x) better understand the biology and identify new targets in triple-negative breast cancer; (xi) better understand immune surveillance in breast cancer and further develop immunotherapies; and (xii) increase survivorship research efforts including supportive care and quality of life.

Bifunctional Elastin-like Polypeptide Nanoparticles Bind Rapamycin and Integrins and Suppress Tumor Growth in Vivo

Recombinant protein-polymer scaffolds such as elastin-like polypeptides (ELPs) offer drug-delivery opportunities including biocompatibility, monodispersity, and multifunctionality. We recently reported that the fusion of FK-506 binding protein 12 (FKBP) to an ELP nanoparticle (FSI) increases rapamycin (Rapa) solubility, suppresses tumor growth in breast cancer xenografts, and reduces side effects observed with free-drug controls. This new report significantly advances this carrier strategy by demonstrating the coassembly of two different ELP diblock copolymers containing drug-loading and tumor-targeting domains. A new ELP nanoparticle (ISR) was synthesized that includes the canonical integrin-targeting ligand (Arg-Gly-Asp, RGD). FSI and ISR mixed in a 1:1 molar ratio coassemble into bifunctional nanoparticles containing both the FKBP domain for Rapa loading and the RGD ligand for integrin binding. Coassembled nanoparticles were evaluated for bifunctionality by performing in vitro cell-binding and drug-retention assays and in vivo MDA-MB-468 breast tumor regression and tumor-accumulation studies. The bifunctional nanoparticle demonstrated superior cell target binding and similar drug retention to FSI; however, it enhanced the formulation potency, such that tumor growth was suppressed at a 3-fold lower dose compared to an untargeted FSI-Rapa control. This data suggests that ELP-mediated scaffolds are useful tools for generating multifunctional nanomedicines with potential activity in cancer.

Detection of clinically relevant copy number alterations in oral cancer progression using multiplexed droplet digital PCR

Copy number alterations (CNAs), a common genomic event during carcinogenesis, are known to affect a large fraction of the genome. Common recurrent gains or losses of specific chromosomal regions occur at frequencies that they may be considered distinctive features of tumoral cells. Here we introduce a novel multiplexed droplet digital PCR (ddPCR) assay capable of detecting recurrent CNAs that drive tumorigenesis of oral squamous cell carcinoma. Applied to DNA extracted from oral cell lines and clinical samples of various disease stages, we found good agreement between CNAs detected by our ddPCR assay with those previously reported using comparative genomic hybridization or single nucleotide polymorphism arrays. Furthermore, we demonstrate that the ability to target specific locations of the genome permits detection of clinically relevant oncogenic events such as small, submicroscopic homozygous deletions. Additional capabilities of the multiplexed ddPCR assay include the ability to infer ploidy level, quantify the change in copy number of target loci with high-level gains, and simultaneously assess the status and viral load for high-risk human papillomavirus types 16 and 18. This novel multiplexed ddPCR assay therefore may have clinical value in differentiating between benign oral lesions from those that are at risk of progressing to oral cancer.

Multifunctional decoration of alpha-tocopheryl succinate-based NP for cancer treatment: effect of TPP and LTVSPWY peptide

Active targeting not only of a specific cell but also a specific organelle maximizes the therapeutic activity minimizing adverse side effects in healthy tissues. The present work describes the synthesis, characterization, and in vitro biological activity of active targeting nanoparticles (NP) for cancer therapy based on α-tocopheryl succinate (α-TOS), a well-known mitocan, that selectively induces apoptosis of cancer cells and proliferalting endothelial cells. Human epidermal growth factor receptor 2 (HER2) targeting peptide LTVSPWY (PEP) and triphenylphosphonium lipophilic cation (TPP) were conjugated to a previously optimized RAFT block copolymer that formed self-assembled NP of appropriate size for this application and low polydispersity by self-organized precipitation method. PEP and TPP were included in order to target not only HER2 positive cancer cells, but also the mitochondria of these cancer cells, respectively. The in vitro experiments demonstrated the faster incorporation of the active-targeting NP and the higher accumulation of TPP-bearing NP in the mitochondria of MDA-MB-453 HER2 positive cancer cells compared to non-decorated NP. Moreover, the encapsulation of additional α-TOS in the hydrophobic core of the NP was achieved with high efficiencies. The loaded NP presented higher cytotoxicity than unloaded NP but preserved their selectivity against cancer cells in a range of tested concentrations.

Does dual HER-2 blockade treatment increase the risk of severe toxicities of special interests in breast cancer patients: A meta-analysis of randomized controlled trials

Although dual HER-2 blockade treatment could offer greater clinical efficacy in breast cancer, the risk of severe toxicities of special interest related to this combined regimen in breast cancer remained unknown. We systematically searched public databases (MEDLINE, EMBASE, Cochrane library) to identify relevant studies that comparing anti-HER2 monotherapy (lapatinib or trastuzumab or pertuzumab) with dual HER-2 blockade treatment (pertuzumab plus trastuzumab or trastuzumab plus lapatinib) in breast cancer. A total of 11,941 breast cancer patients from 9 trials were included for analysis. Meta-analysis showed that dual HER2 blockade treatment significantly increased the risk of severe diarrhea (OR 2.52, p<0.001) and treatment discontinuation (OR 1.52, p=0.014), but not for severe rash (OR 1.06, p=0.81), liver toxicities (OR 1.16, p=0.28), CHF (OR 1.46, p=0.09), LVEF decline (OR 1.09, p=0.40) and FAEs (OR 0.97, p=0.91). Similar results were observed in sub-group analysis according to anti-HER2 regimens in terms of severe diarrhea and treatment discontinuation. Additionally, trastuzumab plus lapatinib significantly increased the risk of LVEF decline in comparison with lapatinib alone (OR 1.48, p=0.002). Our analysis indicated that dual anti-HER2 blockade treatment significantly increased the risk of developing severe diarrhea and treatment discontinuation in comparison with anti-HER2 monotherapy. These were no evidence of an increased risk of fatal adverse events with dual-HER2 blockade treatment.

Exploitation of Gene Expression and Cancer Biomarkers in Paving the Path to Era of Personalized Medicine

Cancer therapy agents have been used extensively as cytotoxic drugs against tissue or organ of a specific type of cancer. With the better understanding of molecular mechanisms underlying carcinogenesis and cellular events during cancer progression and metastasis, it is now possible to use targeted therapy for these molecular events. Targeted therapy is able to identify cancer patients with dissimilar genetic defects at cellular level for the same cancer type and consequently requires individualized approach for treatment. Cancer therapy begins to shift steadily from the traditional approach of “one regimen for all patients” to a more individualized approach, through which each patient will be treated specifically according to their specific genetic defects. Personalized medicine accordingly requires identification of indicators or markers that guide in the decision making of such therapy to the chosen patients for more effective therapy. Cancer biomarkers are frequently used in clinical practice for diagnosis and prognosis, as well as identification of responsive patients and prediction of treatment response of cancer patient. The rapid breakthrough and development of microarray and sequencing technologies is probably the main tool for paving the way toward “individualized biomarker-driven cancer therapy” or “personalized medicine”. In this review, we aim to provide an updated knowledge and overview of the current landscape of cancer biomarkers and their role in personalized medicine, emphasizing the impact of genomics on the implementation of new potential targeted therapies and development of novel cancer biomarkers in improving the outcome of cancer therapy.

Molecular Signaling of Progesterone, Growth Hormone, Wnt, and HER in Mammary Glands of Dogs, Rodents, and Humans: New Treatment Target Identification

Mammary tumors are the most common form of neoplasia in the bitch. Female dogs are protected when they are spayed before the first estrus cycle, but this effect readily disappears and is already absent when dogs are spayed after the second heat. As the ovaries are removed during spaying, ovarian steroids are assumed to play an essential role in tumor development. The sensitivity toward tumor development is already present during early life, which may be caused by early mutations in stem cells during the first estrus cycles. Later on in life, tumors arise that are mostly steroid-receptor positive, although a small subset of tumors overexpressing human epidermal growth factor 2 (HER2) and some lacking estrogen receptor, progesterone receptor (PR), and HER2 (triple negative) are present, as is the situation in humans. Progesterone (P₄), acting through PR, is the major steroid involved in outgrowth of mammary tissue. PRs are expressed in two forms, the progesterone receptor A (PRA) and progesterone receptor B (PRB) isoforms derived from splice variants from a single gene. The dog and the whole family of canids have only a functional PRA isoform, whereas the PRB isoform, if expressed at all, is devoid of intrinsic biological activity. In human breast cancer, overexpression of the PRA isoform is related to more aggressive carcinomas making the dog a unique model to study PRA-related mammary cancer. Administration of P₄ to adult dogs results in local mammary expression of growth hormone (GH) and wing less-type mouse mammary tumor virus integration site family 4 (Wnt4). Both proteins play a role in activation of mammary stem cells. In this review, we summarize what is known on P₄, GH, and Wnt signaling in canine mammary cancer, how the family of HER receptors could interact with this signaling, and what this means for comparative and translational oncological aspects of human breast cancer development.

The erbB3- and IGF-1 receptor-initiated signaling pathways exhibit distinct effects on lapatinib sensitivity against trastuzumab-resistant breast cancer cells

Both erbB3 and IGF-1 receptor (IGF-1R) have been shown to play an important role in trastuzumab resistance. However, it remains unclear whether erbB3- and IGF-1R-initiated signaling pathways possess distinct effects on the sensitivity of lapatinib, a dual tyrosine kinase inhibitor against both EGFR and erbB2, in trastuzumab-resistant breast cancer. Here, we show that the trastuzumab-resistant SKBR3-pool2 and BT474-HR20 breast cancer sublines, as compared the parental SKBR3 and BT474 cells, respectively, exhibit refractoriness to lapatinib. Knockdown of erbB3 inhibited Akt in SKBR3-pool2 and BT474-HR20 cells, significantly increased lapatinib efficacy, and dramatically re-sensitized the cells to lapatinib-induced apoptosis. In contrast, specific knockdown of IGF-1R did not alter the cells' responsiveness to lapatinib. While the levels of phosphorylated Src (P-Src) were reduced upon IGF-1R downregulation, the P-Akt levels remained unchanged. Furthermore, a specific inhibitor of Akt, but not Src, significantly enhanced lapatinib-mediated anti-proliferative/anti-survival effects on SKBR3-pool2 and BT474-HR20 cells. These data indicate that erbB3 signaling is critical for both trastuzumab and lapatinib resistances mainly through the PI-3K/Akt pathway, whereas IGF-1R-initiated Src activation results in trastuzumab resistance without affecting lapatinib sensitivity. Our findings may facilitate the development of precision therapeutic regimens for erbB2-positive breast cancer patients who become resistant to erbB2-targeted therapy.

Judicious Toggling of mTOR Activity to Combat Insulin Resistance and Cancer: Current Evidence and Perspectives

The mechanistic target of rapamycin (mTOR), via its two distinct multiprotein complexes, mTORC1, and mTORC2, plays a central role in the regulation of cellular growth, metabolism, and migration. A dysregulation of the mTOR pathway has in turn been implicated in several pathological conditions including insulin resistance and cancer. Overactivation of mTORC1 and disruption of mTORC2 function have been reported to induce insulin resistance. On the other hand, aberrant mTORC1 and mTORC2 signaling via either genetic alterations or increased expression of proteins regulating mTOR and its downstream targets have contributed to cancer development. These underlined the attractiveness of mTOR as a therapeutic target to overcome both insulin resistance and cancer. This review summarizes the evidence supporting the notion of intermittent, low dose rapamycin for treating insulin resistance. It further highlights recent data on the continuous use of high dose rapamycin analogs and related second generation mTOR inhibitors for cancer eradication, for overcoming chemoresistance and for tumor stem cell suppression. Within these contexts, the potential challenges associated with the use of mTOR inhibitors are also discussed.

Porous Matrix Stiffness Modulates Response to Targeted Therapy in Breast Carcinoma

Porous matrix stiffness modulates response to targeted therapy. Poroelastic behavior within porous matrix may modulate the molecule events in cell-matrix and cell-cell interaction like the complex formation of human epidermal growth factor receptor-2 (HER2)-Src-α6β4 integrin, influencing the targeted therapy with lapatinib.

A Robust Protocol for Using Multiplexed Droplet Digital PCR to Quantify Somatic Copy Number Alterations in Clinical Tissue Specimens

The ability of droplet digital PCR (ddPCR) to accurately determine the concentrations of amplifiable targets makes it a promising platform for measuring copy number alterations (CNAs) in genomic biomarkers. However, its application to clinical samples, particularly formalin-fixed paraffin-embedded specimens, will require strategies to reliably determine CNAs in DNA of limited quantity and quality. When applied to cancerous tissue, those methods must also account for global genetic instability and the associated probability that the abundance(s) of one or more chosen reference loci do not represent the average ploidy of cells comprising the specimen. Here we present an experimental design strategy and associated data analysis tool that enables accurate determination of CNAs in a panel of biomarkers using multiplexed ddPCR. The method includes strategies to optimize primer and probes design to cleanly segregate droplets in the data output from reaction wells amplifying multiple independent templates, and to correct for bias from artifacts such as DNA fragmentation. We demonstrate how a panel of reference loci can be used to determine a stable CNA-neutral benchmark. These innovations, when taken together, provide a comprehensive strategy that can be used to reliably detect biomarker CNAs in DNA extracted from either frozen or FFPE tissue biopsies.

SREBP-1 is an independent prognostic marker and promotes invasion and migration in breast cancer

Re-programming of lipogenic signaling has been previously demonstrated to result in significant alterations in tumor cell pathology. Sterol regulatory element-binding protein 1 (SREBP-1) is a known transcription factor of lipogenic genes. Despite the fact that its functions in proliferation and apoptosis have been elucidated in recent studies, its role in tumor cell migration and invasion, particularly in breast cancer, remains unclear. In present study, the messenger RNA and protein expression levels of SREBP-1 in cancer tissues were observed to be overexpressed compared with those in matched para-cancerous tissues (P<0.01). SREBP-1 level was highly positively correlated with tumor differentiation (P<0.001), tumor-node-metastasis stage (P=0.044) and lymph node metastasis (P<0.001). High expression of SREBP-1 predicted poor prognosis in patients with breast cancer. Additionally, multivariate analysis revealed that SREBP-1 was an independent factor of 5-year overall and disease-specific survival in breast cancer patients (P<0.01). In vitro studies revealed that the suppression of SREBP-1 expression in both MDA-MB-231 and MCF7 cells significantly inhibited cell migration and invasion (P<0.01). The present data indicate that SREBP-1 plays a critical role in breast cancer migration and invasion, and may serve as a prognostic marker of this malignancy.

Cell-specific biomarkers and targeted biopharmaceuticals for breast cancer treatment

Breast cancer is the second leading cause of cancer death among women, and its related treatment has been attracting significant attention over the past decades. Among the various treatments, targeted therapy has shown great promise as a precision treatment, by binding to cancer cell-specific biomarkers. So far, great achievements have been made in targeted therapy of breast cancer. In this review, we first discuss cell-specific biomarkers, which are not only useful for classification of breast cancer subtyping but also can be utilized as goals for targeted therapy. Then, the innovative and generic-targeted biopharmaceuticals for breast cancer, including monoclonal antibodies, non-antibody proteins and small molecule drugs, are reviewed. Finally, we provide our outlook on future developments of biopharmaceuticals, and provide solutions to problems in this field.