Neratinib shows efficacy in the treatment of HER2 amplified carcinosarcoma in vitro and in vivo

Neratinib plus dasatinib is highly synergistic in HER2-positive breast cancer in vitro and in vivo

BACKGROUND

HER2-targeted therapies have revolutionised the treatment of HER2-positive breast cancer. However, de novo resistance or the emergence of acquired resistance is a persistent clinical problem. Here we report that neratinib, an irreversible pan-HER inhibitor, in combination with the multi-kinase inhibitor dasatinib, currently used to treat certain leukemias, has strong anti-proliferative effects against models of HER2-positive breast cancer that are innately resistant to trastuzumab or have acquired resistance to neratinib.

METHODS

Neratinib plus dasatinib was examined in a panel of 20 breast cancer cell lines, including HER2-positive, estrogen-receptor-positive, triple negative, and acquired HER2-targeted therapy resistant models. Drug effects on migration and apoptosis induction was evaluated and signaling alterations were determined by reverse phase protein array (RPPA). In vivo efficacy was examined using orthotopically-implanted HCC1954 cells.

RESULTS

Synergy was observed in cell lines innately resistant to trastuzumab, models with acquired resistance to neratinib, and in triple negative breast cancer cell lines. Further investigation showed that neratinib plus dasatinib induced apoptosis and inhibited cell migration to a greater degree than either drug alone. RPPA revealed that the combination caused suppression of key survival signaling through EGFR, Akt, and MAPK inhibition. In vivo, neratinib plus dasatinib was well tolerated and had a prolonged anti-tumor effect against HCC1954 xenografts.

CONCLUSIONS

This study provides a strong pre-clinical rationale for the clinical investigation neratinib and dasatinib in HER2+ breast cancer.

HER2-negative or low expression as an unfavorable prognostic factor in patients with stage I/II uterine carcinosarcoma

OBJECTIVE

Uterine carcinosarcoma (UCS) is uncommon high-grade endometrial cancer with limited treatment options. We evaluated the prognostic significance of human epidermal growth factor receptor 2 (HER2) expression and HER2 gene amplification within large cohorts of UCS, and clarify clinicopathologic characteristics of HER2-low UCS.

METHODS

We examined HER2 protein expression in 148 patients of UCS using in vivo diagnostic HER2 immunohistochemistry (IHC) kits and HER2 gene amplification using fluorescence in situ hybridization (FISH) in 72 patients.

RESULTS

HER2 IHC score was evaluated according to the latest American Society of Clinical Oncology/College of American Pathologists criteria for gastric cancer, which was negative in 41 patients, low expression of 1+ was observed in 57 patients, and HER2 high expression was observed in 50 patients (2+ in 38 and 3+ in 12 patients). There was no significant statistical difference in clinicopathological characteristics based on HER2 protein expression status. HER2 negative and low expression compared to high expression revealed poor overall survival in stage I/ II. The concordance between IHC and FISH results were relatively low compared to other cancer types (HER2 IHC score 1+, 2+, and 3+ were 5%, 15%, and 50%), and combining these results was not efficient as a prognostic factor in UCS. In contrast, the HER2 IHC score alone was a prognostic factor in stage I/II UCS. HER2 low group did not show specific clinicopathologic features.

CONCLUSION

Since the HER2 IHC score low in advanced UCS is a predictive factor, stratification of UCS using HER2 IHC score for HER2 IHC score low group and developing adjuvant therapy may be proposed in the near future.

Neratinib could be effective as monotherapy or in combination with trastuzumab in HER2-low breast cancer cells and organoid models

BACKGROUND

Previous studies have suggested that patients with HER2-low breast cancers do not benefit from trastuzumab treatment although the reasons remain unclear.

METHODS

We investigated the effect of trastuzumab monotherapy and its combination with different HER2 targeting treatments in a panel of breast cancer cell lines and patient-derived organoids (PDOs) using biochemical methods and cell viability assays.

RESULTS

Compared to sensitive HER2 over-expressing (IHC3 + ) breast cancer cells, increasing doses of trastuzumab could not achieve IC50 in MDA-MB-361 (IHC 2 + FISH + ) and MDA-MB-453 (IHC 2 + FISH-) cells which showed an intermediate response to trastuzumab. Trastuzumab treatment induced upregulation of HER ligand release, resulting in the activation of HER receptors in these cells, which could account for their trastuzumab insensitivity. Adding a dual ADAM10/17 inhibitor to inhibit the shedding of HER ligands in combination with trastuzumab only showed a modest decrease in the cell viability of HER2-low breast cancer cells and PDOs. However, the panHER inhibitor neratinib was an effective monotherapy in HER2-low breast cancer cells and PDOs, and showed additive effects when combined with trastuzumab.

CONCLUSION

This study demonstrates that neratinib in combination with trastuzumab may be effective in a subset of HER2-low breast cancers although further validation is required in a larger panel of PDOs and in future clinical studies.

Genomic and Molecular Characteristics of Ovarian Carcinosarcoma

Ovarian carcinosarcoma (OCS) is a rare malignancy with a poor prognosis. It is a biphasic tumor with malignant epithelial and mesenchymal components. A few mutations commonly seen in cancer have been identified in OCS, including TP53, PIK3CA, c-myc, ZNF217, ARID1A, and CTNNB1. Some OCS tumors have shown vascular endothelial growth factor positivity and limited HER2 expression. There is evidence of homologous recombination deficiency in OCS. This malignancy can be categorized as copy number high but has not been shown to have a high tumor mutational burden. There are mixed findings regarding the presence of biomarkers targeted by immune checkpoint inhibitors in OCS. For treatments other than systemic chemotherapy, the data available are largely based on in vitro and in vivo studies. In addition, there are case reports citing the use of poly-ADP ribose polymerase inhibitors, vascular endothelial growth factor inhibitors, and immunotherapy with varying degrees of success. This review paper will discuss the molecular and genomic characteristics of OCS, which can guide future treatment strategies.

Clinicopathological and molecular analyses of uterine carcinosarcomas using next-generation sequencing: A single-center experience

Background

Uterine carcinosarcomas (UCS) constitute 3-4% of all uterine malignancies and 16% of deaths caused due to uterine neoplasms.

Aim

In this study, we aimed to perform DNA-based mutation analysis in 12 genes (KRAS, NRAS, EGFR, C-KIT, BRAF, PDGFRA, ALK, ERBB2, ERBB3, ESR1, RAF1, PIK3CA) to determine the molecular subtypes of UCS using next-generation sequencing (NGS) in patients with aggressive UCS and poor prognosis. We aimed to compare the results of our analysis with clinicopathological data to contribute to the development of targeted therapy approaches related to the molecular changes of UCS.

Materials and Methods

In this study, we included 12 cases diagnosed with uterine carcinosarcomas and examined the changes in oncogenes that play a role in UCS pathogenesis. For the analysis of mutation, the clinicopathological data were compared with the variations in the DNA-based gene panel consisting of 12 genes and 1237 variants in the UCS using the NGS method.

Results

EGFR mutation was found in 91.7% of the cases, mutation in 41.7%, PDGFRA mutation in 25%, KRAS and PIK3CA mutation in 16.7%, and C-KIT mutation in 8.3% of the cases. Although no statistical significance was found between the detected mutation and clinicopathological data, it was concluded that PDGFRA mutation might be associated with advanced-stage disease development.

Conclusion

This study's findings regarding different molecular types of UCS and information on oncogenesis of UCS can provide inferences for targeted therapies in the future by identifying targetable mutations representing early oncogenic events and thereby contribute toward further studies on this subject.

Trastuzumab Deruxtecan for Human Epidermal Growth Factor Receptor 2-Expressing Advanced or Recurrent Uterine Carcinosarcoma (NCCH1615): The STATICE Trial

PURPOSE

To investigate the efficacy and safety of trastuzumab deruxtecan, an antibody-drug conjugate targeting human epidermal growth factor receptor 2 (HER2) with a topoisomerase I inhibitor payload, in patients with uterine carcinosarcoma (UCS) expressing HER2.

PATIENTS AND METHODS

Patients with recurrent UCS with HER2 immunohistochemistry scores ≥1+ previously treated with chemotherapy were included. Patients were assigned to the HER2-high (immunohistochemistry score ≥2+; n = 22) or low (immunohistochemistry score of 1+; n = 10) groups for primary and exploratory analyses, respectively. Trastuzumab deruxtecan 6.4 or 5.4 mg/kg was administered intravenously once every 3 weeks until unacceptable toxicity or disease progression. Dose modification was based on the updated recommended phase II dose for breast cancer to be 5.4 mg/kg. The primary end point was the objective response rate by central review in the HER2-high group. Secondary end points included the overall response rate (ORR) in the HER2-high group by investigator assessment, ORR in the HER2-low group, progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

The ORR by central review in the HER2-high and HER2-low groups were 54.5% (95% CI, 32.2 to 75.6) and 70.0% (95% CI, 34.8 to 93.3) and those by investigator assessments were 68.2% and 60.0%, respectively. The median PFS and OS in the HER2-high and HER2-low groups were 6.2 and 13.3 months and 6.7 months and not reached, respectively. Grade ≥ 3 adverse events occurred in 20 patients (61%). Grades 1-2 and 3 pneumonitis/interstitial lung disease occurred in eight (24%) and one (3%) patient, respectively.

CONCLUSION

Trastuzumab deruxtecan has efficacy in patients with UCS, regardless of HER2 status. The safety profile was generally consistent with that previously reported. Toxicities were manageable with appropriate monitoring and treatment.

The role of HER2 as a therapeutic biomarker in gynaecological malignancy: potential for use beyond uterine serous carcinoma

Human epidermal growth factor receptor 2 (HER2) is a prognostic biomarker and therapeutic target in carcinomas of the breast, stomach and colon. In 2018, clinical trial data confirmed the prognostic and predictive role of HER2 in uterine serous carcinoma, with a demonstrated survival benefit from combined chemotherapy and anti-HER2 targeted therapy in patients with advanced or recurrent disease. Approximately one-third of uterine serous carcinomas demonstrate HER2 protein overexpression and/or gene amplification and HER2 immunohistochemistry, supplemented by in situ hybridisation in equivocal cases, is fast becoming a reflex ancillary test at time of diagnosis. The potential role of HER2 in gynaecological tumours other than uterine serous carcinoma is yet to be firmly established. With the advent of personalised medicine, routine tumour sequencing and pursuit of targeted therapies, this is a field currently under active investigation. Emerging data suggest triaging endometrial carcinomas for HER2 analysis based on molecular classification may be superior to histotype-based testing, with copy-number high/p53 mutant tumours enriched for HER2 overexpression or amplification. Accordingly, many carcinosarcomas and a subset of clear cell and high-grade endometrioid carcinomas may be eligible for HER2 targeted therapy, although any clinical benefit in this context is currently undefined. For ovarian carcinomas, combined data support the role of HER2 as a prognostic biomarker, however its use as a therapeutic target is yet to be elucidated through clinical trials. In the cervix, reported rates of HER2 overexpression vary and are generally low, and currently there is insufficient evidence to justify routine HER2 testing in this context. Limited data suggest HER2 holds promise as a prognostic and predictive biomarker in vulvar Paget disease. Future clinical trials, with pathologist input to develop and refine site-specific scoring criteria, are required to establish what role HER2 might play more broadly in gynaecological cancer care.

The Prognostic Effect of HER2 Gene Amplification in High-Grade Endometrial Carcinomas and its Correlation with Protein Overexpression

Introduction. New therapeutic agents and biomarkers are needed for the treatment of aggressive endometrial cancer subtypes. Recently, HER2 has been recommended to be tested routinely in serous endometrial cancers. The aim of this study is to investigate the correlation between HER2 (ERBB2) protein overexpression and HER2 gene amplification and the relationship of HER2 gene amplification with prognosis in cancers with serous morphology. In addition, the concordance of HER2 testing in paired curettage and hysterectomy specimens is also investigated. Methods. Twenty five serous carcinomas and 8 carcinosarcomas with a serous morphology were included in the study. HER2 staining was performed on whole tissue sections by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). The system, which was proposed by Fader et al was used to evaluate the stainings. Results. Protein overexpression was detected in 27.3% (n = 9) of the cases, and gene amplification in 30.3% (n = 10). A significant positive correlation was found between the two methods (P < .0001). HER2 IHC revealed a heterogeneous staining pattern, such as intense complete membranous in solid areas, and basolateral in papillary and glandular areas. HER2 gene amplification was significantly associated with shorter overall (P = .005) and disease-free (P = .014) survival. The concordence of the results in curettage and hysterectomy specimens was also significantly high. Conclusion. HER2 is an important prognostic and predictive marker for endometrial cancers with serous morphology. HER2 IHC/ISH testing can be performed by using diagnostic curettage specimens which contain enough viable tumor cells. However, pathologists should be aware of the intratumoral heterogeneity for HER2 staining.

Novel Therapies in Gynecologic Cancer

During the past decade, considerable strides have been made in the understanding and treatment of gynecologic cancers. The advent of PARP inhibitors, antiangiogenic therapies, immunotherapy combinations, and targeted agents have altered the standard of care in ovarian, endometrial, and cervical cancers. However, continued advancement in the treatment of gynecologic cancers is critical. Fortunately, exciting work defining new therapeutic targets and novel treatment strategies is on the horizon. Here, we discuss emerging treatments for gynecologic cancers, including endometrial, cervical, ovarian, and rare gynecologic cancers. We highlight research that has deepened our understanding of the unique biology and molecular underpinnings of these cancers and is being translated into powerful new treatment approaches. We particularly highlight the advent of immunotherapy in endometrial cancer; radiosensitizers in cervical, vaginal, and vulvar cancers; targeted therapies in ovarian cancer; and molecularly driven approaches to treat rare gynecologic cancers. Continued basic, translational, and clinical research holds the promise to change the landscape of gynecologic cancer and improve the lives of all women impacted by these diseases.

Androgen Receptor Immunohistochemical Expression in Undifferentiated/Dedifferentiated Endometrial Carcinoma

Uterine undifferentiated (UC)/dedifferentiated (DEAC) carcinomas are rare malignant neoplasms. They tend to pursue an aggressive clinical course with an advanced stage at presentation. It has been found that androgen receptor (AR) might play a role as a prognostic and therapeutic marker in endometrial carcinoma. However, its expression in UC/DEAC has not been investigated. Herein, the aim of this study was to evaluate the expression of AR along with estrogen receptor (ER), progestin receptor (PR), and HER2 in UC/DEAC and also in other subtypes of high-grade endometrial carcinomas. Review of our pathology database over the period of 2011 to 2019 identified 16 UC/DEAC cases (N=16). We also randomly selected other high-grade endometrial carcinomas including FIGO 3 endometrioid carcinoma (N=9), serous carcinoma (N=8), clear cell carcinoma (N=12) and carcinosarcoma (N=10) for comparison. Immunohistochemical stains for AR, ER, PR, and HER2 were performed on all 55 cases. The protein expression was evaluated both quantitatively and qualitatively. In DEAC cases both the undifferentiated component and the well-differentiated component were recorded separately. Overall, variable degrees of AR reactivity (by Allred scoring method) was present in 63% of UC/DEACs(10/16), 67% of FIGO 3 endometrioid carcinomas (6/9), 88% of serous carcinomas (7/8), 80% of carcinosarcomas (8/10), and 9% of clear cell carcinoma (1/12). AR expression was most often seen with PR (70%) or ER (60%) staining in UC/DEACs. Thirteen cases of UC/DEACs were positive for at least 1 hormone receptor. HER2 was negative in all UC/DEACs. Almost all other high-grade carcinoma cases were negative for HER2 except 20% of carcinosarcoma (2/10) and 13% of serous carcinoma (1/8) which showed 3+ HER2. Loss of AR appears to be associated with worse clinicopathologic parameters in UC/DEAC. AR is highly expressed in UC/DEAC, and in the majority of FIGO 3 endometrioid carcinomas, serous carcinomas, and carcinosarcoma. These findings suggest a potential role for androgen inhibitors in the management of patients with these tumors.

Human epidermal growth factor receptor 2 targeted therapy in endometrial cancer: Clinical and pathological perspectives

Endometrial cancer is the most common gynecological cancer in developed countries, and its incidence has increased. The majority of patients with endometrial cancer have an early disease and favorable prognosis; however, a significant proportion of endometrial cancer, which mainly comprises high-grade or type II endometrial cancer such as serous, clear cell, and carcinosarcoma, shows advanced/recurrent disease and dismal prognosis. Novel therapeutic development is required for patients with aggressive endometrial cancers. Recent genomic and immunohistochemical analyses revealed human epidermal growth factor receptor 2 (HER2) overexpression/gene amplification in 20%-40% of patients with type II endometrial cancer. Historically, HER2 targeted therapy has been developed for various major cancers, including breast and gastric cancer. Notably, recent advances in HER2 targeted therapy for patients with type II endometrial cancer are also expected to change. Simultaneously, an optimized HER2 test for endometrial cancer as companion diagnostics should be established. In this review, we summarize the recent findings on endometrial cancer, current treatment, optimized HER2 testing, key clinical trials on HER2 targeted therapy, and future directions in aggressive endometrial cancer, including serous carcinoma and carcinosarcoma.

Transcriptome analysis of neratinib treated HER2 positive cancer model vs untreated cancer unravels the molecular mechanism of action of neratinib

Human estrogen receptor positive cancer cells have mutations and make an excess of the HER2 protein and are far more aggressive than others cancers. Neratinib, an irreversible tyrosine kinase inhibitor is used to treat HER2 positive cancers. Neratinib targets HER2 and blocks its signal transduction resulting in inhibition of cell proliferation and induction of apoptosis without any information about the molecular mechanism involved. To understand the underlying molecular mechanism transcriptome analysis was carried out in normal vs cancer induced SWR/J nude mice. Cancer was induced in SWR/J nude mice with intraperitoneal injection of 5 × 10⁶ SKBR3 cells for 14 days. Histopathology confirmed the induction of cancer in liver and kidney after the tumor size was at least 0.5 cm. Genome wide Mouse U133 Array was used to analyze the effect of neratinib treatment on cancer. Validation of expression was done by qPCR and ELISA. Microscopic examination revealed that neratinib treatment has potential effects on cancerous liver. Transcriptome expression profiling showed 1481 transcripts differentially expressed by neratinib treatment. Transcriptome Analysis Console (TAC) showed that 532 upregulated transcripts were exclusively belonging to cell cycle, inflammation, olfaction, oxidative stress, HER, and EGFR1 while 949 downregulated transcripts were involved in immunology, drug resistance such as histocompatibility, T cell receptors, and immunoglobulins. The differentially expressed genes were considered significant under the criteria of an adjusted p-value < 0.02 and log2 ratios ≥ 1.0 and/or log2 ratios ≤  − 1.0 means two Fold change. qPCR assay and ELISA analysis was used to validate few genes involved in apoptosis and proliferation. This study provides new insights into the neratinib’s mode of action by cyclin-dependent kinase inhibitor-3 and calcium-activated chloride channel 3 as markers for treatment progress.

Evaluating Trastuzumab in the treatment of HER2 positive breast cancer

The transmembrane oncoprotein HER2 is encoded by ERBB2 gene and overexpressed in around 20% of invasive breast cancers. It can be specifically targeted by Trastuzumab (Herceptin®), a humanised IgG1 antibody. Trastuzumab has been regarded as one of the most effective therapeutic drugs targeted to HER2 positive cancers. However, there are drawbacks, notably cardiotoxicity and resistance, which have raised awareness in clinical use. Therefore, understanding the mechanism of action is vital to establish improved therapeutic strategies. Here we evaluate Trastuzumab application in the treatment of HER2 positive breast cancer, focusing on its mechanistic actions and clinical effectiveness. Alternative therapies targeting the HER2 receptor and its downstream anomalies will also be discussed, as these could highlight further targets that could be key to improving clinical outcomes.

Use of Ex Vivo Patient-Derived Tumor Organotypic Spheroids to Identify Combination Therapies for HER2 Mutant Non-Small Cell Lung Cancer

PURPOSE

Evaluating drug responses using primary patient-derived cells ex vivo represents a potentially rapid and efficient approach to screening for new treatment approaches. Here, we sought to identify neratinib combinations in HER2 mutant non-small cell lung cancer (NSCLC) patient xenograft-derived organotypic spheroids (XDOTS) using a short-term ex vivo system.

EXPERIMENTAL DESIGN

We generated two HER2-mutant NSCLC PDX models [DFCI359 (HER2 exon19 755_757LREdelinsRP) and DFCI315 (HER2 exon20 V777_G778insGSP)] and used the PDX tumors to generate XDOTS. Tumor spheroids were grown in a microfluidic device and treated ex vivo with neratinib-based drug combinations. Live/dead quantification was performed by dual-labeling deconvolution fluorescence microscopy. The most efficacious ex vivo combination was subsequently validated in vivo using the DFCI359 and DFCI315 PDXs and a HER2 ^YVMA genetically engineered mouse model.

RESULTS

Both neratinib and afatinib, but not gefitinib, induced cell death in DFCI359 XDOTS. The combinations of neratinib/trastuzumab and neratinib/temsirolimus enhanced the therapeutic benefit of neratinib alone in DFCI315 and DFCI359. The combination of neratinib and trastuzumab in vivo was more effective compared with single-agent neratinib or trastuzumab and was associated with more robust inhibition of HER2 and downstream signaling.

CONCLUSIONS

The XDOTS platform can be used to evaluate therapies and therapeutic combinations ex vivo using PDX tumors. This approach may accelerate the identification and clinical development of therapies for targets with no or few existing models and/or therapies.

HER2 testing of gynecologic carcinosarcomas: tumor stratification for potential targeted therapy

A recent phase II clinical trial showed increased progression-free survival in patients with HER2-positive endometrial serous carcinoma receiving trastuzumab in addition to carboplatin-paclitaxel chemotherapy. Similar to endometrial serous carcinomas, carcinosarcomas of the female genital tract have a dismal prognosis and could potentially benefit from new targeted therapeutic approaches. We aimed to systematically evaluate the characteristics of HER2 expression/amplification in gynecologic carcinosarcomas using standardized staining methods and scoring criteria. Tumors from 80 patients (65 uterine, 15 tubo-ovarian) were included, containing a serous (60%), endometrioid (10%), clear cell (3%), undifferentiated (3%), neuroendocrine (1%), or mixed (24%) carcinoma, and either a homologous (46%), or a heterologous (54%) sarcoma component. HER2 scores were assigned to both components per the 2007 and 2013 ASCO/CAP breast scoring criteria. A total of 13 cases (12 uterine, 1 ovarian, 16%) were HER2 positive (either by immunohistochemistry or FISH) using the 2013 criteria, while only 10 cases (9 uterine, 1 ovarian, 13%) were HER2 positive per the 2007 criteria. Nine cases showed a change in their HER2 immunohistochemical score between the two scoring systems, including two cases with a change in the overall HER2 status from negative (2007) to positive (2013). Heterogeneity of HER2 protein expression was observed in 38% of HER2-positive tumors, and a lateral/basolateral membranous staining pattern was common. The sarcoma component showed 2+, equivocal HER2 expression in five cases, one of which also demonstrated HER2 amplification by FISH. All HER2-positive carcinosarcomas had either a serous or a mixed carcinoma component, and all but one HER2-positive tumors were of uterine primaries. Our study demonstrates that gynecologic carcinosarcomas share similarities in their HER2 expression/amplification profiles to endometrial serous carcinomas, which should be taken into account when assessing their HER2 status to ensure appropriate patient selection for potential targeted HER2-based therapies in the future.

A Study of the Mechanism of Binding between Neratinib and MAD2L1 Based on Molecular Simulation and Multi-spectroscopy Methods

BACKGROUND

Nilatinib is an irreversible tyrosine kinase inhibitor, which is used in the treatment of some kinds of cancer. To study the interaction between Neratinib and MAD2L1, a potential tumor target, is of guiding significance for enriching the medicinal value of Neratinib.

METHOD

The binding mechanism between Mitotic arrest deficient 2-like protein 1 (MAD2L1) and Neratinib under simulative physiological conditions was investigated by molecule simulation and multi-spectroscopy approaches.

RESULTS

Molecular docking showed the most possible binding mode of Neratinib-MAD2L1 and the potential binding sites and interaction forces of the interaction between MAD2L1 and Neratinib. Fluorescence spectroscopy experiments manifested that Neratinib could interact with MAD2L1 and form a complex by hydrogen bond and van der Waals interaction. These results were consistent with the conclusions obtained from molecular docking. In addition, according to Synchronous fluorescence and three-dimensional fluorescence results, Neratinib might lead to the conformational change of MAD2L1, which may affect the biological functions of MAD2L1.

CONCLUSION

This study indicated that Neratinib could interact with MAD2L1 and lead to the conformational change of MAD2L1. These works provide helpful insights for the further study of biological function of MAD2L1 and novel pharmacological utility of Neratinib.

Endocytic degradation of ErbB2 mediates the effectiveness of neratinib in the suppression of ErbB2-positive ovarian cancer

The tyrosine kinase receptor ErbB2 is frequently found to be overexpressed in multiple cancer types. Targeted therapeutic approaches against ErbB2 have shown promising results and received FDA approvals in the treatment of breast cancer. However, this approach has not been granted in ovarian cancers till now. In order to assess the validity of ErbB2-targeted therapy in ovarian cancer, we investigated the effectiveness of two FDA-approved tyrosine kinase inhibitors of ErbB2, lapatinib and neratinib, on the growth of ovarian cancers. We observed that both lapatinib and neratinib displayed inhibitory effects towards the proliferation and migration of ErbB2-positive ovarian cancer cells in vitro, with neratinib showing stronger suppression in general. Neratinib treatment led to the reduction of ErbB2 protein levels, with concomitant attenuation of the phosphorylation of AKT, MEK, and ERK1/2. Immunofluorescence assays revealed that neratinib induced the internalization and lysosomal degradation of ErbB2, which was accompanied by its hyperubiquitylation. Lapatinib and neratinib also repressed the in vivo growth of SKOV3 cells, and neratinib downregulated ErbB2 levels in xenograft tumors to cause potent inhibition. Therefore, the ubiquitylation-mediated endocytic degradation of ErbB2 incurred by neratinib treatment conferred potent inhibition of ovarian cancer growth. Clinical investigations of neratinib in ErbB2-positive ovarian cancer are warranted.

Genomics of gynaecological carcinosarcomas and future treatment options

Gynaecological carcinosarcomas are the most lethal gynaecological malignancies that are often highly resistant to standard chemotherapy. They are composed of both carcinomatous and sarcomatous components and are associated with high rates of metastatic disease. Due to their rarity, molecular studies have been carried out on relatively few tumours, revealing a broad spectrum of heterogeneity. In this review, we have collated the gene mutations, gene expression, epigenetic regulation and protein expression reported by a number of studies on gynaecological carcinosarcomas. Based on these results, we describe potential therapeutics that may demonstrate efficacy and present any pre-clinical studies that have been carried out. We also describe the pre-clinical models currently available for future research to assess the potential of molecularly matched therapies. Interestingly, over-expression of many biomarkers in carcinosarcoma tumours often doesn't correlate with a worse prognosis. Therefore, we propose that profiling the mutational landscape, gene expression, and gene amplification/deletion may better indicate potential treatment strategies and predict response, thus improving outcomes for women with this rare, aggressive disease.

Neratinib: First Global Approval

Neratinib (Nerlynx™) is an oral, irreversible inhibitor of the human epidermal growth factor receptors HER1 (EGFR), HER2 and HER4. The drug originally arose from research by Wyeth (now Pfizer) and is now being developed by Puma Biotechnology primarily for the treatment of HER2-positive (HER+) breast cancer. Neratinib is approved in the USA for the extended adjuvant treatment of patients with HER2+ early-stage breast cancer who have been previously treated with a trastuzumab-based adjuvant regimen, and is in the preregistration phase for this indication in the EU. Neratinib, as monotherapy and/or combination therapy, is also in phase 3 development for metastatic breast cancer and in phase 1/2 development for advanced breast cancer and other solid tumours, including non-small cell lung cancer, colorectal cancer and glioblastoma. This article summarizes the milestones in the development of neratinib leading to this first approval for breast cancer.

Anti-tumor effect of neratinib against lung cancer cells harboring HER2 oncogene alterations

Human epidermal growth factor receptor 2 (HER2) is a member of the ErbB family of receptor tyrosine kinases. Numerous studies have reported the amplification and overexpression of HER2 in several types of cancer, including non-small cell lung cancer (NSCLC). However, the benefits of HER2-targeted therapy have not been fully established. In the present study, the anti-tumor effect of neratinib, an irreversible pan-HER tyrosine kinase inhibitor (TKI), against NSCLC cells harboring HER2 alterations was investigated. The sensitivity of normal bronchial epithelial cells (BEAS-2B) ectopically overexpressing wild-type or mutant HER2 to neratinib was assessed. Furthermore, the anti-tumor activity of neratinib in several NSCLC cell lines harboring HER2 alterations was determined in vitro and in vivo, and the association between their genetic alterations and sensitivity to neratinib treatment was investigated. BEAS-2B cells ectopically overexpressing wild-type HER2 or mutants (A775insYVMA, G776VC, G776LC, P780insGSP, V659E, G660D and S310F) exhibited constitutive autophosphorylation of HER2, as determined by western blotting. While these BEAS-2B cells were sensitive to neratinib, they were insensitive to erlotinib, a first-generation epidermal growth factor receptor-TKI. Neratinib also exerted anti-proliferative effects on HER2-altered (H2170, Calu-3 and H1781) NSCLC cell lines. Neratinib was also demonstrated to exert strong tumor growth inhibitory activity in mouse xenograft models using HER2-altered lung cancer cells. The results of the present study strongly suggest that neratinib has potential as a promising therapeutic option for the treatment of HER2-altered NSCLC.

Ovarian carcinosarcoma: Current developments and future perspectives

Ovarian carcinosarcoma (OCS) constitute uncommon malignancies accounting for only 1-4% of ovarian cancers. Patients more often present with advanced stage disease and symptoms similar to those of epithelial ovarian cancers (EOC). Optimal tumor cytoreduction appears to be an important determinant of survival. Platinum-based chemotherapy remains the most commonly employed adjuvant treatment. The uncertain origin and poor prognosis of OCS motivate determination of the molecular basis of carcinosarcomas aggressive behavior in the hope of developing novel and effective treatment modalities. The present review summarizes the current knowledge on the epidemiology, pathology, prognostic factors, clinical presentation, and therapeutic interventions including future potential therapeutic targets.

Human epidermal growth factor receptor targeted inhibitors for the treatment of ovarian cancer

Ovarian cancer is the second most lethal gynecological cancer worldwide and while most patients respond to initial therapy, they often relapse with resistant disease. Human epidermal growth factor receptors (especially HER1/EGFR and HER2/ERBB2) are involved in disease progression; hence, strategies to inhibit their action could prove advantageous in ovarian cancer patients, especially in patients resistant to first line therapy. Monoclonal antibodies and tyrosine kinase inhibitors are two classes of drugs that act on these receptors. They have demonstrated valuable antitumor activity in multiple cancers and their possible use in ovarian cancer continues to be studied. In this review, we discuss the human epidermal growth factor receptor family; review emerging clinical studies on monoclonal antibodies and tyrosine kinase inhibitors targeting these receptors in ovarian cancer patients; and propose future research possibilities in this area.

Efficacy of neratinib in the treatment of HER2/neu-amplified epithelial ovarian carcinoma in vitro and in vivo

Epithelial ovarian carcinoma is the most lethal of gynecologic malignancies. There is a need to optimize the currently available treatment strategies and to urgently develop novel therapeutic agents against chemotherapy-resistant disease. The objective of our study was to evaluate neratinib's preclinical efficacy in treating HER2-amplified ovarian cancer. Neratinib's efficacy in treating HER2-amplified ovarian cancer was studied in vitro utilizing six primary tumor cell lines with differential HER2/neu expression. Flow cytometry was utilized to assess IC₅₀, cell signaling changes, and cell cycle distribution. Neratinib's in vivo efficacy was evaluated in HER2-amplified epithelial ovarian carcinoma xenografts. Three of six (50%) ovarian cancer cell lines were HER2/neu-amplified. Neratinib showed significantly higher efficacy in treating HER2/neu-amplified cell lines when compared to the non-HER2/neu-amplified tumor cell lines (mean ± SEM IC₅₀:0.010 μM ± 0.0003 vs. 0.076 μM ± 0.005 p < 0.0001). Neratinib treatment significantly decreased the phosphorylation of the transcription factor S6, leading to arrest of the cell cycle in G0/G1 phase. Neratinib prolonged survival in mice harboring HER2-amplified epithelial ovarian carcinoma xenografts (p = 0.003). Neratinib inhibits proliferation, signaling, cell cycle progression and tumor growth of HER2-amplified epithelial ovarian carcinoma in vitro. Neratinib inhibits xenograft growth and improves overall survival in HER2/neu-amplified ovarian cancer in vivo. Clinical trials are warranted.

Neratinib induces ErbB2 ubiquitylation and endocytic degradation via HSP90 dissociation in breast cancer cells

Receptor tyrosine kinase ErbB2/HER2 is frequently observed to be overexpressed in human cancers, leading to over activation of downstream signaling modules. HER2 positive is a major type of breast cancer for which ErbB2 targeting is already proving to be an effective therapeutic strategy. Apart from antibodies against ErbB2, the small molecule tyrosine kinase inhibitor lapatinib has had successful clinical outcomes, and other inhibitors such as neratinib are currently undergoing clinical investigations. In this study we report the effects of lapatinib and neratinib on the mRNA and protein levels of the ErbB2 receptor. We provide evidence that neratinib-induced down regulation of ErbB2 occurs through ubiquitin-mediated endocytic sorting and lysosomal degradation. At the mechanistic level, neratinib treatment leads to HSP90 release from ErbB2 and its subsequent ubiquitylation and endocytic degradation. Our findings provide novel insights into the mechanism of ErbB2 inhibition by neratinib.

"Carcinosarcoma of the ovary, fallopian tube, and peritoneum: Prognostic factors and treatment modalities"

OBJECTIVE

Ovarian carcinosarcoma (OCS) is a rare malignancy accounting for only 1-4% of all ovarian cancers. The treatment of OCS is largely based on data from small case series and management of other histologic subtypes of epithelial ovarian cancer. We reviewed the literature pertinent to the pathology, pathogenesis, diagnosis, and management of women with OCS.

METHODS

MEDLINE was searched in English for literature on OCS, focusing on the past 30years. Given the rarity of this tumor, studies were not limited by design or number of reported patients.

RESULTS

Molecular, epidemiologic, genetic, and histologic data indicate that most OCS are monoclonal. Patients with OCS generally present with advanced stage disease. Most of the available retrospective studies support the role of cytoreductive surgery in the management of OCS, with optimal debulking associated with improved survival. Platinum-based chemotherapy is the current accepted adjuvant treatment. Given the limited data regarding the management of recurrent OCS, patients are usually treated similarly to women diagnosed with other subtypes of epithelial ovarian cancer.

CONCLUSION

OCS represent a rare and aggressive histologic subtype of epithelial ovarian cancer. The goal of surgery is comprehensive staging in patients with early-stage disease and optimal cytoreduction patients with advanced-stage tumors. Platinum-based chemotherapy is the mainstay of adjuvant systemic treatment. Future studies are needed in order to elucidate the molecular basis for OCS and to evaluate the role of targeted therapy in its management.