Neoadjuvant Chemotherapy Alters Neuropilin-1, PlGF, and SNAI1 Expression Levels and Predicts Breast Cancer Patients Response

Preclinical evaluation of 68 Ga-labeled peptide CK2 for PET imaging of NRP-1 expression in vivo

PURPOSE

Neuropilin-1 (NRP-1) is a multifunctional protein involved in a variety of biological processes such as angiogenesis, tumorigenesis and immunomodulation. It was usually overexpressed in many cancer cell lines and correlated with poor prognosis of breast cancer. Positron emission tomography (PET) is an advanced imaging technique for detecting the function and metabolism of tumor-associated molecules in real time, dynamically, quantitatively and noninvasively. To improve the level of early diagnosis and evaluate the prognosis of breast cancer, an NRP-1 targeting peptide-based tracer [68 Ga]Ga-NOTA-PEG4-CK2 was designed to sensitively and specifically detect the NRP-1 expression in vivo via PET imaging.

METHODS

In silico modeling and microscale thermophoresis (MST) assay were carried out to design the NRP-1 targeting peptide NOTA-PEG4-CK2, and it was further radiolabeled with 68 Ga to prepare the tracer [68 Ga]Ga-NOTA-PEG4-CK2. The radiochemical yield (RCY), radiochemical purity (RCP), molar activity (Am), lipid-water partition coefficient (Log P) and stability of [68 Ga]Ga-NOTA-PEG4-CK2 were assessed. The targeting specificity of the tracer for NRP-1 was investigated by in vitro cellular uptake assay and in vivo PET imaging as well as blocking studies. The sensitivity of the tracer in monitoring the dynamic changes of NRP-1 expression induced by chemical drug was also investigated in vitro and in vivo. Ex vivo biodistribution, autoradiography, western blot, and immunofluorescence staining were also performed to study the specificity of [68 Ga]Ga-NOTA-PEG4-CK2 for NRP-1.

RESULTS

[68 Ga]Ga-NOTA-PEG4-CK2 was designed and synthesized with high RCY (> 98%), high stability (RCP > 95%) and high affinity to NRP-1 (KD = 25.39 ± 1.65 nM). In vitro cellular uptake assay showed that the tracer [68 Ga]Ga-NOTA-PEG4-CK2 can specifically bind to NRP-1 positive cancer cells MDA-MB-231 (1.04 ± 0.04% at 2 h) rather than NRP-1 negative cancer cells NCI-H1299 (0.43 ± 0.05%). In vivo PET imaging showed the maximum tumor uptake of [68 Ga]Ga-NOTA-PEG4-CK2 in MDA-MB-231 xenografts (4.16 ± 0.67%ID/mL) was significantly higher than that in NCI-H1299 xenografts (1.03 ± 0.19%ID/mL) at 10 min post injection, and the former exhibited higher tumor-to-muscle uptake ratio (5.22 ± 0.18) than the latter (1.07 ± 0.27) at 60 min post injection. MDA-MB-231 xenografts pretreated with nonradioactive precursor NOTA-PEG4-CK2 showed little tumor uptake of [68 Ga]Ga-NOTA-PEG4-CK2 (1.67 ± 0.38%ID/mL at 10 min post injection). Both cellular uptake assay and PET imaging revealed that NRP-1 expression in breast cancer MDA-MB-231 could be effectively suppressed by SB-203580 treatment and can be sensitively detected by [68 Ga]Ga-NOTA-PEG4-CK2. Ex vivo analysis also proved the high specificity and sensitivity of [68 Ga]Ga-NOTA-PEG4-CK2 for NRP-1 expression in MDA-MB-231 xenografts.

CONCLUSION

A promising NRP-1 targeting PET tracer [68 Ga]Ga-NOTA-PEG4-CK2 was successfully prepared. It showed remarkable specificity and sensitivity in monitoring the dynamic changes of NRP-1 expression. Hence, it could provide valuable information for early diagnosis of NRP-1 relevant cancers and evaluating the prognosis of cancer patients.

Neuropilin-1 and placental growth factor as prognostic factors in metastatic breast cancer

BACKGROUND

Angiogenesis is crucial for tumor development, progression, and metastasizing. The most important regulator of angiogenesis is the vascular endothelial growth factor (VEGF) family, which is involved in multiple pathways in tumor microenvironment. The objective of this study was to investigate the prognostic value of the VEGF family in patients treated for metastatic breast cancer. The emphasis was on neuropilin-1 (NRP-1) and placental growth factor (PlGF).

MATERIALS AND METHODS

An analysis of eight members of the VEGF family was performed using baseline plasma samples of 65 patients treated for metastatic HER2 negative breast cancer in a phase II first-line bevacizumab plus chemotherapy trial. The patients were divided into two groups, high or low, according to the median for each VEGF family member. Progression-free survival (PFS) and overall survival (OS) were determined for each VEGF family member.

RESULTS

The patients with low plasma levels of NRP-1 and PlGF had a longer OS than those with high plasma levels [multivariable adjusted hazard ratios (HRs) 2.54 (95% confidence interval (CI) 1.11-5.82, p = 0.02) and 3.11 (95% CI 1.30-7.47, p = 0.01), respectively]. The patients with low levels of both NRP-1 and PlGF had a remarkably long OS with HR of 6.24, (95% CI 1.97-19.76, p = 0.002). In addition, high baseline NRP-1 level was associated with a significantly shorter PFS [multivariable adjusted HR 2.90 (95% CI 1.02-8.28, p = 0.04)] than that in the low-level group, and a high baseline vascular endothelial growth factor receptor-2 level was associated with a longer PFS [multivariable adjusted HR 0.43 (95% CI 0.19-0.98, p = 0.04)].

CONCLUSION

Especially NRP-1 and PlGF have prognostic potential in metastatic breast cancer patients treated with a bevacizumab-taxane combination. Patients with low plasma levels of NRP-1 or PlGF have longer OS than patients with high levels. Patients with both low NRP-1 and PlGF levels appear to have excellent long-term survival.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00979641, registration date 18/09/2009. The regional Ethics Committee: R08142M, registration date 18/11/2008.

Glucocorticoid induced loss of oestrogen receptor alpha gene methylation and restoration of sensitivity to fulvestrant in triple negative breast cancer

The response to psychological stress can differ depending on the type and duration of the stressor. Acute stress can facilitate a "fight or flight response" and aid survival, whereas chronic long-term stress with the persistent release of stress hormones such as cortisol has been shown to be detrimental to health. We are now beginning to understand how this stress hormone response impacts important processes such as DNA repair and cell proliferation processes in breast cancer. However, it is not known what epigenetic changes stress hormones induce in breast cancer. Epigenetic mechanisms include modification of DNA and histones within chromatin that may be involved in governing the transcriptional processes in cancer cells in response to changes by endogenous stress hormones. The contribution of endogenous acute or long-term exposure of glucocorticoid stress hormones, and exogenous glucocorticoids to methylation patterns in breast cancer tissues with different aetiologies remains to be evaluated. In vitro and in vivo models were developed to investigate the epigenetic modifications and their contribution to breast cancer progression and aetiology. A panel of triple negative breast cancer cell lines were treated with the glucocorticoid, cortisol which resulted in epigenetic alteration characterised by loss of methylation on promoter regions of tumour suppressor genes including ESR1, and loss of methylation on LINE-1 repetitive element used as a surrogate marker for global methylation. This was verified in vivo in MDA-MB-231 xenografts; the model verified the loss of methylation on ESR1 promoter, and subsequent increase in ESR1 expression in primary tumours in mice subjected to restraint stress. Our study highlights that DNA methylation landscape in breast cancer can be altered in response to stress and glucocorticoid treatment.

Neuropilin (NRPs) Related Pathological Conditions and Their Modulators

Neuropilin 1 (NRP1) represents one of the two homologous neuropilins (NRP, splice variants of neuropilin 2 are the other) found in all vertebrates. It forms a transmembrane glycoprotein distributed in many human body tissues as a (co)receptor for a variety of different ligands. In addition to its physiological role, it is also associated with various pathological conditions. Recently, NRP1 has been discovered as a coreceptor for the SARS-CoV-2 viral entry, along with ACE2, and has thus become one of the COVID-19 research foci. However, in addition to COVID-19, the current review also summarises its other pathological roles and its involvement in clinical diseases like cancer and neuropathic pain. We also discuss the diversity of native NRP ligands and perform a joint analysis. Last but not least, we review the therapeutic roles of NRP1 and introduce a series of NRP1 modulators, which are typical peptidomimetics or other small molecule antagonists, to provide the medicinal chemistry community with a state-of-the-art overview of neuropilin modulator design and NRP1 druggability assessment.

Neuropilin-1 as a Potential Biomarker of Prognosis and Invasive-Related Parameters in Liver and Colorectal Cancer: A Systematic Review and Meta-Analysis of Human Studies

Simple Summary

Neuropilin-1 (NRP1) is a transmembrane protein which has had recently increased interest from cancer researchers. Liver cancer and colorectal cancer (CRC) are two of the most frequent and deadly tumors worldwide. Here, we assessed the prognostic, diagnostic and clinicopathological value of NRP1 in liver cancer and CRC patients by systematic searches in PubMed, Scopus, Web of Science, Embase and Cochrane Library and a meta-analysis. Results obtained showed that NRP1 overexpression was significantly correlated with lower survival in liver cancer patients and with tumor development in hepatocarcinoma patients, and high levels of NRP1 were strongly correlated with an increased risk of vascular invasion in liver cancer and metastasis in CRC and liver tumors. Therefore, these findings could establish novel interest of NRP1 as a useful biomarker for patient prognosis as well as for invasive-related characteristics in patients with liver cancer or CRC.

Abstract

Neuropilin-1 (NRP1) is a transmembrane protein involved in numerous cellular functions which has had increasing interest from cancer researchers. Liver cancer and colorectal cancer (CRC) are two of the most frequent and deadly tumors with a complex pharmacological framework. Here, we assessed the prognostic, diagnostic and clinicopathological value of NRP1 in liver cancer and CRC patients. We searched PubMed, Scopus, Web of Science, Embase and Cochrane Library databases for articles evaluating the NRP1 correlation with survival parameters, tumor development or clinicopathological features. Hazard ratios and odds ratios with 95% confidence intervals were extracted or estimated by Parmar method and pooled to evaluate the overall effect size with STATA 16 software. Heterogeneity was analyzed by chi-square-based Q test and I² statistic, along with meta-regression and subgroup analysis, and publication bias was assessed by funnel plot asymmetry and Egger’s test. The study protocol was registered in PROSPERO (CRD42022307062). NRP1 overexpression was significantly correlated with lower survival in liver cancer patients and with tumor development in hepatocarcinoma patients, and was strongly correlated with an increased risk of vascular invasion in liver cancer and metastasis in CRC and liver tumors. These results support the role of NRP1 as a potential and useful biomarker in both types of cancer.

Brain Microvascular Pericytes—More than Bystanders in Breast Cancer Brain Metastasis

Brain tissue contains the highest number of perivascular pericytes compared to other organs. Pericytes are known to regulate brain perfusion and to play an important role within the neurovascular unit (NVU). The high phenotypic and functional plasticity of pericytes make this cell type a prime candidate to aid physiological adaptations but also propose pericytes as important modulators in diverse pathologies in the brain. This review highlights known phenotypes of pericytes in the brain, discusses the diverse markers for brain pericytes, and reviews current in vitro and in vivo experimental models to study pericyte function. Our current knowledge of pericyte phenotypes as it relates to metastatic growth patterns in breast cancer brain metastasis is presented as an example for the crosstalk between pericytes, endothelial cells, and metastatic cells. Future challenges lie in establishing methods for real-time monitoring of pericyte crosstalk to understand causal events in the brain metastatic process.

PIGF and Flt-1 on the surface of macrophages induces the production of TGF-β1 by polarized tumor-associated macrophages to promote lung cancer angiogenesis

BACKGROUND

The interaction between tumor cells and tumor microenvironment is a necessary condition for promoting the metastasis of malignant tumors.

METHODS

Two different transwell culture systems were interfered with by recombinant factor placental growth factor (re-PIGF) and the re-PIGF + transforming growth factor-β1 (TGF-β1)-neutralizing antibody (anti-TGF-β1). We performed immunofluorescence, flow cytometry and enzyme linked immunosorbent assay (ELISA) to analyze the expression of PIGF, fms-like tyrosine kinase-1 (Flt-1), macrophage marker F4/80 ⁺, macrophage M2 marker CD163⁺ and TGF-β1 in vitro. Meanwhile, cell viability assay and optical microscope assay were conducted to explore the cell viability and vascularization ability of human umbilical vein endothelial cells (HUVECs).

RESULTS

Re-PIGF increased the expression of PIGF in A549 cells and the expression of Flt-1 in BM-Mac cells, and significantly enhanced the ability of bone marrow-derived macrophages (BM-Mac) to transform into macrophages. At the same time, re-PIGF increased the expression of cytokine TGF-β1 in A549 cells/BM-Mac transwell culture system. On the contrary, re-PIGF + anti-TGF-β1 inhibited the expression of Flt-1 in BM-Mac cells and inhibited the ability of BM-Mac cells to transform into macrophages. Finally, re-PIGF + anti-TGF-β1 reduced the cell viability and angiogenesis of HUVECs.

CONCLUSION

The surface molecule PIGF of lung cancer cells could bind to the receptor Flt-1 on the surface of macrophages, thereby increasing the production of TGF-β1, and ultimately promoting the formation of angiogenesis in lung cancer.

Soluble Neuropilin-1 is an independent marker of poor prognosis in early breast cancer

Background

Neuropilin-1 (NRP-1) is a transmembrane protein that acts as a multifunctional non-tyrosine kinase receptor with an established role in development and immunity. NRP-1 also regulates tumor biology, and high expression levels of tissue NRP-1 have been associated with a poor prognosis. Recently, ELISA-based quantification of soluble NRP-1 (sNRP-1) has become available, but little is known about the prognostic value of sNRP-1 in malignancies.

Materials and methods

We measured sNRP-1 in the serum of 509 patients with primary early breast cancer (BC) at the time of diagnosis using ELISA.

Results

Mean serum values of sNRP-1 were 1.88 ± 0.52 nmol/l (= 130.83 ± 36.24 ng/ml). SNRP-1 levels weakly correlated with age, and were higher in peri- and postmenopausal patients compared to premenopausal patients, respectively (p < 0.0001). Low levels of sNRP-1 were associated with a significant survival benefit compared to high sNRP-1 levels at baseline (p = 0.005; HR 1.94; 95%CI 1.23–3.06). These findings remained significant after adjustment for tumor stage including lymph node involvement, grading, hormone receptor, HER2 status, and age (p = 0.022; HR 1.78; 95%CI 1.09–2.91).

Conclusion

Our findings warrant further investigations into the prognostic and therapeutic potential of sNRP-1 in BC.

The miR-124-3p/Neuropilin-1 Axis Contributes to the Proliferation and Metastasis of Triple-Negative Breast Cancer Cells and Co-Activates the TGF-β Pathway

Triple-negative breast cancer (TNBC) accounts for 90% of breast cancer-associated mortality. Neuropilin-1 (NRP-1) acts as a non-tyrosine kinase receptor for several cellular signaling pathways involved in the proliferation and metastasis of cancer cells. However, the miRNAs that regulate NRP-1 expression and the underlying mechanisms in TNBC cells remain unclear. In the present study, we found that TNBC cells expressed higher levels of NRP-1 than non-TNBC cells. Stable transfectants depleted of NRP-1 were generated from two TNBC cell lines, human MDA-MB-231 and mouse 4T1 cells. NRP-1 depletion significantly suppressed the proliferation of TNBC cells by arresting the cell cycle at phase G0/G1 by upregulating p27 and downregulating cyclin E and cyclin-dependent kinase 2. NRP-1 depletion also repressed cell migration and epithelial-mesenchymal transition (EMT) by inducing the upregulation of E-cadherin and the downregulation of N-cadherin, matrix metalloproteinase (MMP)-2 and MMP-9, and reducing MMP-2 and MMP-9 activities as detected by gelatin zymography assay. By applying multiple miRNA-target prediction tools, we screened potential miRNAs with binding sites with the 3’-untranslated region of the NRP-1 gene and selected 12 miRNA candidates, among which miR-124-3p displayed the most vigorous activity to downregulate NRP-1 as validated by luciferase assay and miRNA transfection assay. By downregulating NRP-1, miR-124-3p mimics inhibited the proliferation, migration, and invasion of TNBC cells, and antagomiR-124-3p could partially abolish the effects of NRP-1 depletion. In the animal experiments, NRP-1 depletion inhibited tumorigenesis and liver metastasis of TNBC cells, while miR-124-3p mimics inhibited the growth of established TNBC tumors. In the mechanistic exploration, we revealed that NRP-1 co-interacted with transforming growth factor (TGF)-β to activate the TGF-β pathway, which regulates EMT-related molecules. In summary, the present results indicate that the miR-124-3p/NRP-1 axis contributes to the proliferation and metastasis of TNBC cells and co-activates the TGF-β pathway, suggesting that these molecules may present as potential therapeutic targets and valuable biomarkers for TNBC.

Modeling Neoadjuvant chemotherapy resistance in vitro increased NRP-1 and HER2 expression and converted MCF7 breast cancer subtype

BACKGROUND AND PURPOSE

Patients with locally advanced breast cancer usually receive third-generation neoadjuvant chemotherapy (NAC). Although NAC treatment improved the overall survival, patients' response varies, some acquire resistance and others exhibit a conversion in their breast cancer molecular subtype. We aimed to identify the molecular changes involved in NAC resistance attempting to find new therapeutic targets in different breast cancer subtypes.

EXPERIMENTAL APPROACH

We modelled NAC treatments used in clinical practice and generated resistant cell lines in vitro. The resistant cells were generated by consecutive treatment with four cycles of doxorubicin (adriamycin)/cyclophosphamide (4xAC) followed by an additional four cycles of paclitaxel (4xAC + 4xPAC).

KEY RESULTS

Our data revealed distinct mechanisms of resistance depending on breast cancer subtype and drugs used. MDA-MB-231 cells resistant to 4xAC + 4xPAC activated neuropilin-1/TNC/integrin β3/FAK/NF-κBp65 axis and displayed a decrease in breast cancer resistance protein (BCRP/ABCB2). However, MCF7 cells resistant to 4xAC treatments induced HER2 expression, which converted MCF7 subtype from luminal A to luminal B HER2 type, up-regulated neuropilin-1, oestrogen receptor-α, and EGFR, and activated PI3K/Akt/NF-κBp65 axis. However, MCF7 cells resistant to 4xAC + 4xPAC exhibited down-regulation of the survival axis and up-regulated BCRP/ABCG2. Co-immunoprecipitation demonstrated a novel interaction between HER2 and neuropilin-1 driving the resistance features.

CONCLUSIONS AND IMPLICATIONS

The concurrent increase in neuropilin-1 and HER2 upon resistance and the inverse relationship between neuropilin-1 and BCRP/ABCG2 suggest that, in addition to HER2, neuropilin-1 status should be assessed in patients undergoing NAC, and as a potential drug target for refractory breast cancer.

Relationship between neuropilin-1 expression and prognosis, according to gastric cancer histology

Neuropilin-1 (NRP-1) is known to be related to various types of cancer and is considered a novel tumor marker or therapeutic target. The aim of this study was to identify the clinical implications of NRP-1 expression in terms of prognosis in patients with gastric cancer. A total of 265 patients who underwent radical gastrectomy for the treatment of gastric cancer from 2008 to 2011 were included in this retrospective study. NRP-1 expression of tumors was determined by immunohistochemistry. The patients' clinicopathological characteristics, operative details, and long-term outcomes were retrospectively analyzed. A total of 181 (68.3%) patients demonstrated expression of NRP-1. No survival difference was observed according to NRP-1 expression in any patient. The patients were divided into the gland formation (GF) and the no gland formation (nGF) types, according to histology. NRP-1 expression rates were 65.6% (84/128) and 70.8% (97/137), respectively. NRP-1 expression was not an independent prognostic factor in the GF group, although patients who expressed NRP-1 had better survival outcomes. In contrast, patients who expressed NRP-1 in the nGF group had worse 5-year survival rates (p = 0.027), and NRP-1 was an independent prognostic factor in a multivariate analysis (hazard ratio, 1.923; 95% confidence interval, 1.041-3.551). NRP-1 expression in patients with nGF type gastric cancer is predictive of a poor prognosis.