Biomarkers of response and resistance to antiangiogenic therapy

Recent advances and future directions on small molecule VEGFR inhibitors in oncological conditions

"A journey of mixed emotions" is a quote that best describes the progress chart of vascular endothelial growth factor receptor (VEGFR) inhibitors as cancer therapeutics in the last decade. Exhilarated with the Food and Drug Administration (FDA) approvals of numerous VEGFR inhibitors coupled with the annoyance of encountering the complications associated with their use, drug discovery enthusiasts are on their toes with an unswerving determination to enhance the rate of translation of VEGFR inhibitors from preclinical to clinical stage. The recently crafted armory of VEGFR inhibitors is a testament to their growing dominance over other antiangiogenic therapies for cancer treatment. This review perspicuously underscores the earnest attempts of the researchers to extract the antiproliferative potential of VEGFR inhibitors through the design of mechanistically diverse structural assemblages. Moreover, this review encompasses sections on structural/molecular properties and physiological functions of VEGFR, FDA-approved VEGFR inhibitors, and hurdles restricting the activity range/clinical applicability of VEGFR targeting antitumor agents. In addition, tactics to overcome the limitations of VEGFR inhibitors are discussed. A clear-cut viewpoint transmitted through this compilation can provide practical directions to push the cart of VEGFR inhibitors to advanced-stage clinical investigations in diverse malignancies.

Havoc in harmony: Unravelling the intricacies of angiogenesis orchestrated by the tumor microenvironment

Cancer cells merely exist in isolation; rather, they exist in an intricate microenvironment composed of blood vessels, signalling molecules, immune cells, stroma, fibroblasts, and the ECM. The TME provides a setting that is favourable for the successful growth and survivance of tumors. Angiogenesis is a multifaceted process that is essential for the growth, invasion, and metastasis of tumors. TME can be visualized as a "concert hall," where various cellular and non-cellular factors perform in a "symphony" to orchestrate tumor angiogenesis and create "Havoc" instead of "Harmony". In this review, we comprehensively summarized the involvement of TME in regulating tumor angiogenesis. Especially, we have focused on immune cells and their secreted factors, inflammatory cytokines and chemokines, and their role in altering the TME. We have also deciphered the crosstalk among various cell types that further aids the process of tumor angiogenesis. Additionally, we have highlighted the limitations of existing anti-angiogenic therapy and discussed various potential strategies that could be used to overcome these challenges and improve the efficacy of anti-angiogenic therapy.

CD133-containing microvesicles promote colorectal cancer progression by inducing tumor angiogenesis

Angiogenesis is an indispensable mechanism in cancer progression, as cancer cells need to establish blood vessels to supply oxygen and nutrients. Extracellular vesicles (EVs) derived from cancer cells act as messengers in the tumor microenvironment and induce resistance to anti-angiogenic cancer treatment. EVs can be classified into two categories: exosomes and microvesicles (MVs). Although exosomes are involved in angiogenesis, the role of MVs in angiogenesis and cancer progression remains unclear. CD133 plays a key role in MV formation and oncoprotein trafficking. In this study, we investigated the role of CD133-containing MVs derived from colorectal cancer (CRC) in angiogenesis and cancer progression. CRC-derived MVs were incorporated into endothelial cells and increased the mesh area and tube length of endothelial cells. CD133-containing MVs also stimulate vessel sprouting in endothelial cell spheroids and mouse thoracic aortas. However, MVs derived from CD133-knockdown CRC cells exerted a limited effect on tube formation and vessel sprouting. CD133-containing MVs induced angiogenesis through p38 activation and angiogenesis induced by CD133-containing MVs was insensitive to the anti-vascular endothelial growth factor antibody bevacizumab. Survival analysis revealed that high expression level of CD133 correlated with poor prognosis in patients with metastatic CRC. These findings suggest that CD133-containing MVs act as key regulators of angiogenesis and are related to the prognosis of CRC patients.

Translational research on drug development and biomarker discovery for hepatocellular carcinoma

Translational research plays a key role in drug development and biomarker discovery for hepatocellular carcinoma (HCC). However, unique challenges exist in this field because of the limited availability of human tumor samples from surgery, the lack of homogenous oncogenic driver mutations, and the paucity of adequate experimental models. In this review, we provide insights into these challenges and review recent advancements, with a particular focus on the two main agents currently used as mainstream therapies for HCC: anti-angiogenic agents and immunotherapy. First, we examine the pre-clinical and clinical studies to highlight the challenges of determining the optimal therapeutic combinations with biologically effective dosage for HCC. Second, we discuss biomarker studies focusing on anti-PD1/anti-PD-L1-based combination therapy. Finally, we discuss the progress made in our collective understanding of tumor immunology and in multi-omics analysis technology, which enhance our understanding of the mechanisms underlying immunotherapy, characterize different patient subgroups, and facilitate the development of novel combination approaches to improve treatment efficacy. In summary, this review provides a comprehensive overview of efforts in translational research aiming at advancing our understanding of and improving the treatment of HCC.

Pattern recognition of microcirculation with super-resolution ultrasound imaging provides markers for early tumor response to anti-angiogenic therapy

Rationale: Cancer treatment outcome is traditionally evaluated by tumor volume change in clinics, while tumor microvascular heterogeneity reflecting tumor response has not been fully explored due to technical limitations. Methods: We introduce a new paradigm in super-resolution ultrasound imaging, termed pattern recognition of microcirculation (PARM), which identifies both hemodynamic and morphological patterns of tumor microcirculation hidden in spatio-temporal space trajectories of microbubbles. Results: PARM demonstrates the ability to distinguish different local blood flow velocities separated by a distance of 24 μm. Compared with traditional vascular parameters, PARM-derived heterogeneity parameters prove to be more sensitive to microvascular changes following anti-angiogenic therapy. Particularly, PARM-identified "sentinel" microvasculature, exhibiting evident structural changes as early as 24 hours after treatment initiation, correlates significantly with subsequent tumor volume changes (|r| > 0.9, P < 0.05). This provides prognostic insight into tumor response much earlier than clinical criteria. Conclusions: The ability of PARM to noninvasively quantify tumor vascular heterogeneity at the microvascular level may shed new light on early-stage assessment of cancer therapy.

Clinical and Prognostic Biomarker Value of Blood-Circulating Inflammatory Cytokines in Hepatocellular Carcinoma

INTRODUCTION

Circulating inflammatory cytokines play critical roles in tumor-associated inflammation and immune responses. Recent data have suggested that several interleukins (ILs) mediate carcinogenesis in hepatocellular carcinoma (HCC). However, the predictive and prognostic value of circulating ILs is yet to be validated. Our study aimed to evaluate the association of the serum ILs with overall survival (OS) and clinicopathologic features in a large cohort of HCC patients.

METHODS

We prospectively collected data and serum samples from 767 HCC patients treated at the University of Texas MD Anderson Cancer Center between 2001 and 2014, with a median follow-up of 67.4 months (95% confidence interval [CI]: 52.5, 83.3). Biomarker association with OS was evaluated by the log-rank method.

RESULTS

The median OS in this cohort was 14.2 months (95% CI: 12, 16.1 months). Clinicopathologic features were more advanced, and OS was significantly inferior in patients with high circulating levels of IL1-R1, IL-6, IL-8, IL-10, IL-15, IL-16, and IL-18.

CONCLUSION

Our study shows that several serum IL levels are valid prognostic biomarker candidates and potential targets for therapy in HCC.

Murine Breast Cancer Radiosensitization Using Oxygen Microbubbles and Metformin: Vessels Are the Key

Radiotherapy is a cornerstone of cancer treatment, but tumor hypoxia and resistance to radiation remain significant challenges. Vascular normalization has emerged as a strategy to improve oxygenation and enhance therapeutic outcomes. In this study, we examine the radiosensitization potential of vascular normalization using metformin, a widely used anti-diabetic drug, and oxygen microbubbles (OMBs). We investigated the synergistic action of metformin and OMBs and the impact of this therapeutic combination on the vasculature, oxygenation, invasiveness, and radiosensitivity of murine 4T1 breast cancer. We employed in vivo Doppler ultrasonographic imaging for vasculature analysis, electron paramagnetic resonance oximetry, and immunohistochemical assessment of microvessels, perfusion, and invasiveness markers. Our findings demonstrate that both two-week metformin therapy and oxygen microbubble treatment normalize abnormal cancer vasculature. The combination of metformin and OMB yielded more pronounced and sustained effects than either treatment alone. The investigated therapy protocols led to nearly twice the radiosensitivity of 4T1 tumors; however, no significant differences in radiosensitivity were observed between the various treatment groups. Despite these improvements, resistance to treatment inevitably emerged, leading to the recurrence of hypoxia and an increased incidence of metastasis.

Angiogenesis and Hepatocellular Carcinoma: From Molecular Mechanisms to Systemic Therapies

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. The hypervascular nature of the majority of HCCs and the peculiar vascular derangement occurring during liver carcinogenesis underscore the importance of angiogenesis in the development and progression of these tumors. Indeed, several angiogenic molecular pathways have been identified as deregulated in HCC. The hypervascular nature and the peculiar vascularization of HCC, as well as deregulated angiogenic pathways, represent major therapeutic targets. To a large extent, intra-arterial locoregional treatments (transarterial-(chemo)embolization) rely on tumor ischemia caused by embolization of tumor feeding arteries, even though this may represent the "primum movens" of tumor recurrence through the activation of neoangiogenesis. Considering systemic therapies, the currently available tyrosine kinase inhibitors (sorafenib, regorafenib, cabozantinib and lenvatinib) and monoclonal antibodies (ramucirumab and bevacizumab, in combination with the anti-PD-L1, atezolizumab) primarily target, among others, angiogenic pathways. Considering the importance of angiogenesis in the pathogenesis and treatment of liver cancer, in this paper, we aim to review the role of angiogenesis in HCC, addressing the molecular mechanisms, available antiangiogenic therapies and prognostic biomarkers in patients receiving these treatments.

Angiogenic signaling pathways and anti-angiogenic therapy for cancer

Angiogenesis, the formation of new blood vessels, is a complex and dynamic process regulated by various pro- and anti-angiogenic molecules, which plays a crucial role in tumor growth, invasion, and metastasis. With the advances in molecular and cellular biology, various biomolecules such as growth factors, chemokines, and adhesion factors involved in tumor angiogenesis has gradually been elucidated. Targeted therapeutic research based on these molecules has driven anti-angiogenic treatment to become a promising strategy in anti-tumor therapy. The most widely used anti-angiogenic agents include monoclonal antibodies and tyrosine kinase inhibitors (TKIs) targeting vascular endothelial growth factor (VEGF) pathway. However, the clinical benefit of this modality has still been limited due to several defects such as adverse events, acquired drug resistance, tumor recurrence, and lack of validated biomarkers, which impel further research on mechanisms of tumor angiogenesis, the development of multiple drugs and the combination therapy to figure out how to improve the therapeutic efficacy. Here, we broadly summarize various signaling pathways in tumor angiogenesis and discuss the development and current challenges of anti-angiogenic therapy. We also propose several new promising approaches to improve anti-angiogenic efficacy and provide a perspective for the development and research of anti-angiogenic therapy.

Multiple parameters from ultrafast dynamic contrast-enhanced magnetic resonance imaging to discriminate between benign and malignant breast lesions: Comparison with apparent diffusion coefficient

PURPOSE

The purpose of this study was first to assess the diagnostic performance of ultrafast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters compared to apparent diffusion coefficient (ADC) for distinguishing benign from malignant breast lesions and second to investigate the complementarity of ultrafast DCE-MRI with DWI in that task.

MATERIALS AND METHODS

A total of 142 women (mean age, 48.42 ± 11.03 [SD]) years; range: 14-78 years) with 150 breast lesions who underwent breast ultrafast DCE-MRI were prospectively recruited. Ultrafast DCE-MRI semi-quantitative parameters (maximum slope [MS], time to peak [TTP], time to enhancement [TTE], and initial area under curve in 60 s [iAUC]), ultrafast DCE-MRI quantitative parameters (K_ep, K_trans, and V_e), and the ADC were estimated and compared between benign and malignant breast lesions. Classification performances were assessed using area under the receiver operating characteristic curve (AUC) and compared using Delong test.

RESULTS

The ultrafast DCE-MRI semi-quantitative multiparameters (AUC, 0.913; 95% CI: 0.856-0.953) showed better classification performance than the quantitative multiparameters (AUC, 0.818; 95% CI: 0.747-0.876) (P = 0.022). No differences in AUC were found between ultrafast DCE-MRI semi-quantitative multiparameters and ADC (AUC, 0.912; 95% CI: 0.855-0.952) (P = 0.990). The combination of ultrafast DCE-MRI semi-quantitative multiparameters and ADC (AUC, 0.960; 95% CI: 0.915-0.985) showed better classification performance than the ultrafast DCE-MRI semi-quantitative multiparameters (P = 0.014) and quantitative multiparameters (P < 0.001).

CONCLUSION

Ultrafast DCE-MRI can be used as an accurate method for discriminating benign from malignant breast lesions. The combination of ultrafast DCE-MRI and DWI significantly increases the diagnostic value of ultrafast DCE-MRI.

Multitasking dynamic contrast enhanced magnetic resonance imaging can accurately differentiate chronic pancreatitis from pancreatic ductal adenocarcinoma

Background and aims

Accurate differentiation of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) is an area of unmet clinical need. In this study, a novel Multitasking dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) technique was used to quantitatively evaluate the microcirculation properties of pancreas in CP and PDAC and differentiate between them.

Methods

The Multitasking DCE technique was able to acquire one 3D image per second during the passage of MRI contrast agent, allowing the quantitative estimation of microcirculation properties of tissue, including blood flow F_p, plasma volume fraction v_p, transfer constant K^trans, and extravascular extracellular volume fraction v_e. Receiver operating characteristic (ROC) analysis was performed to differentiate the CP pancreas, PDAC pancreas, normal control pancreas, PDAC tumor, PDAC upstream, and PDAC downstream. ROCs from quantitative analysis and conventional analysis were compared.

Results

Fourteen PDAC patients, 8 CP patients and 20 healthy subjects were prospectively recruited. The combination of F_p, v_p, K^trans, and v_e can differentiate CP versus PDAC pancreas with good AUC (AUC [95% CI] = 0.821 [0.654 - 0.988]), CP versus normal pancreas with excellent AUC (1.000 [1.000 - 1.000]), PDAC pancreas versus normal pancreas with excellent AUC (1.000 [1.000 - 1.000]), CP versus PDAC tumor with excellent AUC (1.000 [1.000 - 1.000]), CP versus PDAC downstream with excellent AUC (0.917 [0.795 - 1.000]), and CP versus PDAC upstream with fair AUC (0.722 [0.465 - 0.980]). This quantitative analysis outperformed conventional analysis in differentiation of each pair.

Conclusion

Multitasking DCE MRI is a promising clinical tool that is capable of unbiased quantitative differentiation between CP from PDAC.

Drug susceptibility testing of circulating lung cancer cells for personalized treatment

The presence of Circulating tumor cells (CTCs) has been proven to be correlated with disease progression and the patient's response to treatment. However, the culture of CTCs for clinical utility is still a big challenge. We have developed a short-term method that enables CTCs culture and provides an opportunity to monitor drug susceptibility testing in individual patients. In a proof-of-concept study, we established a unique method using Matrigel® coated in 96 well plate to enable cancer cell clusters to attach and proliferate. The culture method using Matrigel® provides in vitro conditions and improves the attachment and differentiation of anchorage-dependent epithelial cells proliferation and mimics the tumor microenvironment. We further treated the cells attached to Matrigel® with the same drug regimen as the patient has undergone. Around 30.7% of the CTCs were viable after the drug treatment. We also correlated the decrease in cell viability after drug treatment with the reduction in the pleural effusion of the patient as seen by the images obtained from CT scans pre-and post-treatment. Moreover, as per the RECIST criterion, the patient had exhibited a positive response to the treatment. The short-term culturing of CTC along with the drug susceptibility testing offers a novel method to predict patient response to the treatment and could be utilized for screening suitable drug combinations for personalized treatment.

Senescence and cancer - role and therapeutic opportunities

Cellular senescence is a state of stable, terminal cell cycle arrest associated with various macromolecular changes and a hypersecretory, pro-inflammatory phenotype. Entry of cells into senescence can act as a barrier to tumorigenesis and, thus, could in principle constitute a desired outcome for any anticancer therapy. Paradoxically, studies published in the past decade have demonstrated that, in certain conditions and contexts, malignant and non-malignant cells with lastingly persistent senescence can acquire pro-tumorigenic properties. In this Review, we first discuss the major mechanisms involved in the antitumorigenic functions of senescent cells and then consider the cell-intrinsic and cell-extrinsic factors that participate in their switch towards a tumour-promoting role, providing an overview of major translational and emerging clinical findings. Finally, we comprehensively describe various senolytic and senomorphic therapies and their potential to benefit patients with cancer.

The entry of cells into senescence can act as a barrier to tumorigenesis; however, in certain contexts senescent malignant and non-malignant cells can acquire pro-tumorigenic properties. The authors of this Review discuss the cell-intrinsic and cell-extrinsic mechanisms involved in both the antitumorigenic and tumour-promoting roles of senescent cells, and describe the potential of various senolytic and senomorphic therapeutic approaches in oncology.

Cellular senescence is a natural barrier to tumorigenesis; senescent cells are widely detected in premalignant lesions from patients with cancer.

Cellular senescence is induced by anticancer therapy and can contribute to some treatment-related adverse events (TRAEs).

Senescent cells exert both protumorigenic and antitumorigenic effects via cell-autonomous and paracrine mechanisms.

Pharmacological modulation of senescence-associated phenotypes has the potential to improve therapy efficacy and reduce the incidence of TRAEs.

Case report: Long-term partial response of apatinib plus paclitaxel as second-line therapy in a patient with metastatic gastric cancer

Gastric cancer is the second most prevalent cancer and the second leading cause of cancer-related death in China. The prognosis of metastatic gastric cancer is poor with a median overall survival of 8–10 months. Apatinib, an oral small-molecule, selective vascular endothelial growth factor receptor-2 tyrosine kinase inhibitor, is approved as third-line or subsequent therapy for gastric cancer in China. Several recent small-scale studies and case reports showed that it may be great help in improvement of prognosis as second-line treatment in patients with advanced or metastatic gastric cancer. Here, we present a case of advanced gastric adenocarcinoma with multiple hepatic metastases who was treated with apatinib plus paclitaxel as second-line therapy, realized a long progression-free survival of 37 months. Until 29 January 2022, the disease remains an efficacy of partial response. We believe that the good outcome of this case is not an accident, because of the typically hyper-vascular of his liver metastases, the treatment toxicities of hypertension and proteinuria, all may be potential predictive biomarkers for anti-angiogenic treatments.

Molecular Biomarkers in Glioblastoma: A Systematic Review and Meta-Analysis

Background: Glioblastoma (GBM) is a highly aggressive cancer with poor prognosis that needs better treatment modalities. Moreover, there is a lack of reliable biomarkers to predict the response and outcome of current or newly designed therapies. While several molecular markers have been proposed as potential biomarkers for GBM, their uptake into clinical settings is slow and impeded by marker heterogeneity. Detailed assessment of prognostic and predictive value for biomarkers in well-defined clinical trial settings, if available, is scattered throughout the literature. Here we conducted a systematic review and meta-analysis to evaluate the prognostic and predictive significance of clinically relevant molecular biomarkers in GBM patients. Material and methods: A comprehensive literature search was conducted to retrieve publications from 3 databases (Pubmed, Cochrane and Embase) from January 2010 to December 2021, using specific terms. The combined hazard ratios (HR) and confidence intervals (95% CI) were used to evaluate the association of biomarkers with overall survival (OS) in GBM patients. Results: Twenty-six out of 1831 screened articles were included in this review. Nineteen articles were included in the meta-analyses, and 7 articles were quantitatively summarised. Fourteen studies with 1231 GBM patients showed a significant association of MGMT methylation with better OS with the pooled HR of 1.66 (95% CI 1.32−2.09, p < 0.0001, random effect). Five studies including 541 GBM patients analysed for the prognostic significance of IDH1 mutation showed significantly better OS in patients with IDH1 mutation with a pooled HR of 2.37 (95% CI 1.81−3.12; p < 0.00001]. Meta-analysis performed on 5 studies including 575 GBM patients presenting with either amplification or high expression of EGFR gene did not reveal any prognostic significance with a pooled HR of 1.31 (95% CI 0.96−1.79; p = 0.08). Conclusions: MGMT promoter methylation and IDH1 mutation are significantly associated with better OS in GBM patients. No significant associations were found between EGFR amplification or overexpression with OS.

Early increase of plasma soluble VEGFR-2 is associated with clinical benefit from second-line treatment of paclitaxel and ramucirumab in advanced gastric cancer

Ramucirumab plus paclitaxel is considered the standard of care in the second-line treatment of gastric carcinoma (GC). The aim of this study was to evaluate plasma vascular endothelial growth factor-A (VEGF-A), VEGF-D, and circulating soluble VEGF receptor-2 (sVEGFR-2) as possible markers of resistance or response to ramucirumab administered with paclitaxel in pretreated metastatic GC patients. Plasma samples were collected at different time points (on days 1 and 15 of the first 3 cycles, at best radiologic response and at disease progression). VEGF-A, VEGF-D and sVEGFR-2 were analysed by ELISA. Correlations of biomarker baseline levels or dynamic changes with outcome measures were assessed. Progression-free survival (PFS) was the primary endpoint of the study. Forty-one patients were enrolled. VEGF-A and VEGF-D, but not sVEGFR-2, values significantly increased during treatment compared to baseline (P < 0.001). A positive correlation between VEGF-A and sVEGFR-2 at cycle 2 was found (P=0.045). At univariate analysis, higher baseline levels of VEGF-A were associated with worse OS (P=0.015). Early increase of sVEGFR-2 levels after the first treatment cycle was the only factor associated with longer PFS (6.6 vs. 3.6 months, P=0.049) and OS (18.6 vs. 5.2 months, P=0.008). Significance of sVEGFR-2 early increase was retained at multivariate analysis for OS (HR 0.32; 95% CI 0.12-0.91; P=0.032). The reported results confirmed the prognostic role of baseline VEGF-A and, with the limitations of the limited sample size and the lack of a control arm, suggested that the early increase of sVEGFR-2 after 1 cycle of treatment could be a potential predictive biomarker of benefit from second-line ramucirumab plus paclitaxel in GC.

Cancer combination therapies by angiogenesis inhibitors; a comprehensive review

Abnormal vasculature is one of the most conspicuous traits of tumor tissue, largely contributing to tumor immune evasion. The deregulation mainly arises from the potentiated pro-angiogenic factors secretion and can also target immune cells' biological events, such as migration and activation. Owing to this fact, angiogenesis blockade therapy was established to fight cancer by eliminating the nutrient and oxygen supply to the malignant cells by impairing the vascular network. Given the dominant role of vascular-endothelium growth factor (VEGF) in the angiogenesis process, the well-known anti-angiogenic agents mainly depend on the targeting of its actions. However, cancer cells mainly show resistance to anti-angiogenic agents by several mechanisms, and also potentiated local invasiveness and also distant metastasis have been observed following their administration. Herein, we will focus on clinical developments of angiogenesis blockade therapy, more particular, in combination with other conventional treatments, such as immunotherapy, chemoradiotherapy, targeted therapy, and also cancer vaccines. Video abstract.

Treatment-related adverse events as predictive biomarkers of efficacy in patients with advanced neuroendocrine tumors treated with surufatinib: results from two phase III studies

Background

No validated biomarkers currently exist for predicting the efficacy outcomes in patients with neuroendocrine tumors (NETs) treated with antiangiogenic therapy. We aimed to evaluate the association between treatment-related adverse events (TRAEs) and efficacy outcomes of surufatinib in patients with advanced NET.

Patients and methods

We included patients with NET treated with surufatinib in two multicenter, randomized, double-blind, placebo-controlled, phase III trials (SANET-p and SANET-ep) in this study. The main exposure was the presence of any of the TRAEs including hypertension, proteinuria, and hemorrhage in the first 4 weeks of surufatinib treatment. The primary outcome of the study was investigator-assessed progression-free survival (PFS). PFS outcomes were estimated using the Kaplan–Meier method with the log-rank test. Hazard ratios (HRs) were calculated by using univariable and multivariable Cox proportional hazard regression models. Blinded independent image review committee (BIIRC) assessments and 4-week landmark analysis were also performed as supportive evaluations.

Results

During the study period, a total of 242 patients treated with surufatinib were included in the analysis, and 164 (68%) patients had at least one of hypertension, proteinuria, and hemorrhage in the first 4 weeks of treatment. The presence of TRAEs in the first 4 weeks was associated with prolonged median PFS [11.1 versus 9.2 months; HR 0.67, 95% confidence interval (CI) 0.47-0.97; P = 0.036]. In multivariable Cox regression analysis, the presence of TRAEs was also significantly associated with longer PFS (HR 0.65, 95% CI 0.44-0.97; P = 0.035). Similar results were obtained in the BIIRC assessments and 4-week landmark analysis.

Conclusions

Treatment-related hypertension, proteinuria, and hemorrhage could be potential biomarkers to predict antitumor efficacy of surufatinib in patients with advanced NET. Future prospective studies are needed to validate the findings.

Trial registration

ClinicalTrials.govNCT02589821; https://clinicaltrials.gov/ct2/show/NCT02589821 and ClinicalTrials.gov NCT02588170; https://clinicaltrials.gov/ct2/show/NCT02588170

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Treatment-related hypertension, proteinuria, or hemorrhage is associated with longer survival in NETs.

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The association is confirmed by the BIIRC assessments and 4-week landmark analysis.

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TRAEs can be biomarkers to predict antitumor efficacy in patients with NET.

Bridging the macro to micro resolution gap with angiographic optical coherence tomography and dynamic contrast enhanced MRI

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Safety of ramucirumab treatment in patients with advanced hepatocellular carcinoma and elevated alpha-fetoprotein

INTRODUCTION

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-induced deaths worldwide, and limited therapeutic options are available for patients with advanced disease. Ramucirumab, a monoclonal antibody that blocks the vascular endothelial growth factor (VEGF) receptor-2, is the first biomarker-selected systemic agent with therapeutic efficacy, tolerability, and favorable patient-reported outcomes in patients with advanced HCC and elevated serum α-fetoprotein levels ≥400 ng/mL, who are resistant or intolerant to sorafenib therapy. However, treatment-induced adverse events (AEs), such as hypertension, proteinuria, bleeding, thromboembolism, and gastrointestinal perforation remain challenging and potentially fatal concerns.

AREAS COVERED

This review discusses the published or ongoing studies and subgroup analyses on ramucirumab therapy in patients with advanced HCC. We present information on the risks of ramucirumab-induced common or rare AEs and their management.

EXPERT OPINION

Ramucirumab toxicity secondary to VEGF inhibition is similar to the AEs that are known to be associated with other VEGF-blocking antibodies. Common AEs can be safely treated using conventional measures; however, rare and potentially fatal AEs necessitate close monitoring. With regard to the safety profile, more promising ramucirumab-containing combination therapies are likely to pave the future path for effective HCC treatment.

Characterization of Anti-angiogenic Chemo-sensitization via Longitudinal Ultrasound Localization Microscopy in Colorectal Carcinoma Tumor Xenografts

OBJECTIVE

Super-resolution ultrasound localization microscopy (ULM) has unprecedented vascular resolution at clinically relevant imaging penetration depths. This technology can potentially screen for the transient microvascular changes that are thought to be critical to the synergistic effect(s) of combined chemotherapy-antiangiogenic agent regimens for cancer.

METHODS

In this paper, we apply this technology to a high-throughput colorectal carcinoma xenograft model treated with either the antiangiogenic agent sorafenib, FOLFOX-6 chemotherapy, a combination of the two treatments, or vehicle control.

RESULTS

Longitudinal ULM demonstrated morphological changes in the antiangiogenic treated cohorts, and evidence of vascular disruption caused by chemotherapy. Gold-standard histological measurements revealed reduced levels of hypoxia in the sorafenib treated cohort for both of the human cell lines tested (HCT-116 and HT-29). Therapy resistance was associated with an increase in tumor vascular fractal dimension as measured by a box-counting technique on ULM images.

CONCLUSION

These results imply that the morphological changes evident on ULM signify a functional change in the tumor microvasculature, which may be indicative of chemo-sensitivity.

SIGNIFICANCE

ULM provides additional utility for tumor therapy response evaluation by offering a myriad of morphological and functional quantitative indices for gauging treatment effect(s).

Machine Learning for Future Subtyping of the Tumor Microenvironment of Gastro-Esophageal Adenocarcinomas

Tumor progression involves an intricate interplay between malignant cells and their surrounding tumor microenvironment (TME) at specific sites. The TME is dynamic and is composed of stromal, parenchymal, and immune cells, which mediate cancer progression and therapy resistance. Evidence from preclinical and clinical studies revealed that TME targeting and reprogramming can be a promising approach to achieve anti-tumor effects in several cancers, including in GEA. Thus, it is of great interest to use modern technology to understand the relevant components of programming the TME. Here, we discuss the approach of machine learning, which recently gained increasing interest recently because of its ability to measure tumor parameters at the cellular level, reveal global features of relevance, and generate prognostic models. In this review, we discuss the relevant stromal composition of the TME in GEAs and discuss how they could be integrated. We also review the current progress in the application of machine learning in different medical disciplines that are relevant for the management and study of GEA.

Dietary tomato inhibits angiogenesis in TRAMP prostate cancer but is not protective with a Western-style diet in this pilot study

Prostate cancer (PCa) remains the second most diagnosed cancer worldwide. Higher body weight is associated with chronic inflammation, increased angiogenesis, and treatment-resistant tumor phenotypes. Dietary tomato reduces PCa risk, which may be due to tomato inhibition of angiogenesis and disruption of androgen signaling. This pilot study investigated the interplay between tomato powder (TP), incorporated into control (CON) and obesogenic (OB) diets, and PCa tumor growth and blood perfusion over time in a transgenic model of PCa (TRAMP). Ultrasound microvessel imaging (UMI) results showed good agreement with gold-standard immunohistochemistry quantification of endothelial cell density, indicating that this technique can be applied to non-invasively monitor tumor blood perfusion in vivo. Greater body weight was positively associated with tumor growth. We also found that TP significantly inhibited prostate tumor angiogenesis but that this inhibition differentially affected measured outcomes depending on CON or OB diets. TP led to reduced tumor growth, intratumoral inflammation, and intratumoral androgen-regulated gene expression (srd5a1, srd5a2) when incorporated with the CON diet but greater tumor growth and intratumoral gene expression when incorporated with the OB diet. Results from this study show that protective benefits from dietary tomato are lost, or may become deleterious, when combined with a Western-style diet.

CD63-mediated cloaking of VEGF in small extracellular vesicles contributes to anti-VEGF therapy resistance

Despite wide use of anti-vascular endothelial growth factor (VEGF) therapy for many solid cancers, most individuals become resistant to this therapy, leading to disease progression. Therefore, new biomarkers and strategies for blocking adaptive resistance of cancer to anti-VEGF therapy are needed. As described here, we demonstrate that cancer-derived small extracellular vesicles package increasing quantities of VEGF and other factors in response to anti-VEGF therapy. The packaging process of VEGF into small extracellular vesicles (EVs) is mediated by the tetraspanin CD63. Furthermore, small EV-VEGF (eVEGF) is not accessible to anti-VEGF antibodies and can trigger intracrine VEGF signaling in endothelial cells. eVEGF promotes angiogenesis and enhances tumor growth despite bevacizumab treatment. These data demonstrate a mechanism where VEGF is partitioned into small EVs and promotes tumor angiogenesis and progression. These findings have clinical implications for biomarkers and therapeutic strategies for ovarian cancer.

Mechanism-Centric Approaches for Biomarker Detection and Precision Therapeutics in Cancer

Biomarker discovery is at the heart of personalized treatment planning and cancer precision therapeutics, encompassing disease classification and prognosis, prediction of treatment response, and therapeutic targeting. However, many biomarkers represent passenger rather than driver alterations, limiting their utilization as functional units for therapeutic targeting. We suggest that identification of driver biomarkers through mechanism-centric approaches, which take into account upstream and downstream regulatory mechanisms, is fundamental to the discovery of functionally meaningful markers. Here, we examine computational approaches that identify mechanism-centric biomarkers elucidated from gene co-expression networks, regulatory networks (e.g., transcriptional regulation), protein-protein interaction (PPI) networks, and molecular pathways. We discuss their objectives, advantages over gene-centric approaches, and known limitations. Future directions highlight the importance of input and model interpretability, method and data integration, and the role of recently introduced technological advantages, such as single-cell sequencing, which are central for effective biomarker discovery and time-cautious precision therapeutics.

Distinct MRI pattern of "pseudoresponse" in recurrent glioblastoma multiforme treated with regorafenib: Case report and literature review

Antiangiogenic agents can induce a distinct MRI pattern in glioblastoma, characterized by a decrease in the contrast enhancement on T1-weighted images and a simultaneous hyperintensity on T2-weighted or fluid-attenuated inversion recovery images.

A Brief Overview and Update on Major Molecular Genomic Alterations in Solid, Bone and Soft Tissue Tumors, Hematopoietic As Well As Lymphoid Malignancies

CONTEXT.—

Recent advances in comprehensive genomic profiling by next-generation sequencing have uncovered the genomic alterations at the molecular level for many types of tumors; as such, numerous small specific molecules that target these alterations have been developed and widely used in the management of these cancers.

OBJECTIVE.—

To provide a concise molecular genomic update in solid, bone and soft tissue tumors, hematopoietic as well as lymphoid malignancies; discuss its clinical applications; and familiarize practicing pathologists with the emerging cancer biomarkers and their diagnostic utilities.

DATA SOURCES.—

This review is based on the National Comprehensive Cancer Network guidelines and peer-reviewed English literature.

CONCLUSIONS.—

Tumor-specific biomarkers and molecular/genomic alterations, including pan-cancer markers, have been significantly expanded in the past decade thanks to large-scale high-throughput technologies and will continue to emerge in the future. These biomarkers can be of great value in diagnosis, prognosis, and/or targeted therapy/treatment. Familiarization with these emerging and ever-changing tumor biomarkers will undoubtedly aid pathologists in making accurate and state-of-the-art diagnoses and enable them to be more actively involved in the care of cancer patients.

The Anti-VEGF(R) Drug Discovery Legacy: Improving Attrition Rates by Breaking the Vicious Cycle of Angiogenesis in Cancer

Resistance to anti-vascular endothelial growth factor (VEGF) molecules causes lack of response and disease recurrence. Acquired resistance develops as a result of genetic/epigenetic changes conferring to the cancer cells a drug resistant phenotype. In addition to tumor cells, tumor endothelial cells also undergo epigenetic modifications involved in resistance to anti-angiogenic therapies. The association of multiple anti-angiogenic molecules or a combination of anti-angiogenic drugs with other treatment regimens have been indicated as alternative therapeutic strategies to overcome resistance to anti-angiogenic therapies. Alternative mechanisms of tumor vasculature, including intussusceptive microvascular growth (IMG), vasculogenic mimicry, and vascular co-option, are involved in resistance to anti-angiogenic therapies. The crosstalk between angiogenesis and immune cells explains the efficacy of combining anti-angiogenic drugs with immune check-point inhibitors. Collectively, in order to increase clinical benefits and overcome resistance to anti-angiogenesis therapies, pan-omics profiling is key.

Paracrine Placental Growth Factor Signaling in Response to Ionizing Radiation Is p53-Dependent and Contributes to Radioresistance

Placental growth factor (PlGF) is a pro-angiogenic, N-glycosylated growth factor, which is secreted under pathologic situations. Here, we investigated the regulation of PlGF in response to ionizing radiation (IR) and its role for tumor angiogenesis and radiosensitivity. Secretion and expression of PlGF was induced in multiple tumor cell lines (medulloblastoma, colon and lung adenocarcinoma) in response to irradiation in a dose- and time-dependent manner. Early upregulation of PlGF expression and secretion in response to irradiation was primarily observed in p53 wild-type tumor cells, whereas tumor cells with mutated p53 only showed a minimal or delayed response. Mechanistic investigations with genetic and pharmacologic targeting of p53 corroborated regulation of PlGF by the tumor suppressor p53 in response to irradiation under normoxic and hypoxic conditions, but with so far unresolved mechanisms relevant for its minimal and delayed expression in tumor cells with a p53-mutated genetic background. Probing a paracrine role of IR-induced PlGF secretion in vitro, migration of endothelial cells was specifically increased towards irradiated PlGF wild type but not towards irradiated PlGF-knockout (PIGF-ko) medulloblastoma cells. Tumors derived from these PlGF-ko cells displayed a reduced growth rate, but similar tumor vasculature formation as in their wild-type counterparts. Interestingly though, high-dose irradiation strongly reduced microvessel density with a concomitant high rate of complete tumor regression only in the PlGF-ko tumors. IMPLICATIONS: Our study shows a strong paracrine vasculature-protective role of PlGF as part of a p53-regulated IR-induced resistance mechanism and suggest PlGF as a promising target for a combined treatment modality with RT.

Prevalence of hypoxia and correlation with glycolytic metabolism and angiogenic biomarkers in metastatic colorectal carcinoma

PURPOSE

Hypoxia is associated with aggressive tumour behaviour and can influence response to systemic therapy and radiotherapy. The prevalence of hypoxia in metastatic colorectal cancer is poorly understood, and the relationship of hypoxia to patient outcomes has not been clearly established. The aims of the study were to evaluate hypoxia in metastatic colorectal cancer with [18F]Fluoromisonidazole ([18F]FMISO PET) and correlate these findings with glycolytic metabolism ([18F]FDG PET) and angiogenic blood biomarkers and patient outcomes.

METHODS

Patients with metastatic colorectal cancer received routine staging investigations and both [18F] FMISO PET and [18F] FDG PET scans. Correlative blood specimens were also obtained at the time of the [18F] FMISO PET scan. Patient follow-up was performed to establish progression-free survival.

RESULTS

A total of 40 patients were recruited into the trial. [18F]FMISO and [18F]FDG PET scans showed a significant correlation of SUVmax (p = 0.003). A significant correlation of progression-free survival and [18F] FMISO TNR (p = 0.02) and overall survival with [18F]FMISO TNR (p = 0.003) and [18F]FDG TGV (p = 0.02) was observed. Serum levels of osteopontin, but not VEGF, correlated with [18F] FMISO and [18F]FDG PET scan parameters.

CONCLUSION

[18F]FMISO PET uptake in metastatic colorectal cancer significantly correlates with glycolytic metabolism and is predictive of progression-free and overall survival. These findings have implications for the assessment and treatment of metastatic colorectal cancer patients with novel therapies which affect tumour angiogenesis and hypoxia.

The Molecular Mechanisms of Cardiotoxicity Induced by HER2, VEGF, and Tyrosine Kinase Inhibitors: an Updated Review

AIM

In recent decades, there has been a revolutionary decrease in cancer-related mortality and an increase in survival due to the introduction of novel targeted drugs. Nevertheless, drugs targeting human epidermal growth factor receptor 2 (HER-2), angiogenesis, and other tyrosine kinases also come with unexpected cardiac side effects, including heart failure, hypertension, arterial thrombosis, and arrhythmias, and have mechanisms that are unlike those of classic chemotherapeutic agents. In addition, it is challenging to address some problems, as the existing guidelines need to be more specific, and further large-scale clinical trials and experimental studies are required to confirm the benefit of administering cardioprotective agents to patients treated with targeted therapies. Therefore, an improved understanding of cardiotoxicity becomes increasingly important to minimize the pernicious effects and maximize the beneficial effects of targeted agents.

METHODS

"Cardiotoxicity", "targeted drugs", "HER2", "trastuzumab", "angiogenesis inhibitor", "VEGF inhibitor" and "tyrosine kinase inhibitors" are used as keywords for article searches.

RESULTS

In this article, we report several targeted therapies that induce cardiotoxicity and update knowledge of the clinical evidence, molecular mechanisms, and management measures.

The role of c-Met and VEGFR2 in glioblastoma resistance to bevacizumab

Dismal prognosis of glioblastoma (GBM) prompts for the identification of response predictors and therapeutic resistance mechanisms of current therapies. The authors investigated the impact of c-Met, HGF, VEGFR2 expression and microvessel density (MVD) in GBM patients submitted to second-line chemotherapy with bevacizumab. Immunohistochemical expression of c-Met, HGF, VEGFR2, and MVD was assessed in tumor specimens of GBM patients treated with bevacizumab, after progression under temozolomide. Survival analysis was evaluated according to the expression of the aforementioned biomarkers. c-Met overexpression was associated with a time-to-progression (TTP) after bevacizumab of 3 months (95% CI, 1.5-4.5) compared with a TTP of 7 months (95% CI, 4.6-9.4) in patients with low or no expression of c-Met (p = 0.05). VEGFR2 expression was associated with a TTP after bevacizumab of 3 months (95% CI, 1.8-4.2) compared with a TTP of 7 months (95% CI, 5.7-8.3) in patients with no tumoral expression of VEGFR2 (p = 0.009). Concomitant c-Met/VEGFR2 overexpression was associated with worse overall survival (13 months) compared with concomitant c-Met/VEGFR2 negative expression (19 months; p = 0.025). Our data support the hypothesis that c-Met and VEGFR2 overexpression have a role in the development of glioblastoma early resistance and might predict poorer responses to anti-angiogenic therapies.

Tumour angiogenesis normalized by myo-inositol trispyrophosphate alleviates hypoxia in the microenvironment and promotes antitumor immune response

Pathologic angiogenesis directly responds to tumour hypoxia and controls the molecular/cellular composition of the tumour microenvironment, increasing both immune tolerance and stromal cooperation with tumour growth. Myo-inositol-trispyrophosphate (ITPP) provides a means to achieve stable normalization of angiogenesis. ITPP increases intratumour oxygen tension (pO₂ ) and stabilizes vessel normalization through activation of endothelial Phosphatase-and-Tensin-homologue (PTEN). Here, we show that the tumour reduction due to the ITPP-induced modification of the tumour microenvironment by elevating pO₂ affects the phenotype and properties of the immune infiltrate. Our main observations are as follows: a relative change in the M1 and M2 macrophage-type proportions, increased proportions of NK and CD8⁺ T cells, and a reduction in Tregs and Th2 cells. We also found, in vivo and in vitro, that the impaired access of PD1⁺ NK cells to tumour cells is due to their adhesion to PD-L1⁺ /PD-L2⁺ endothelial cells in hypoxia. ITPP treatment strongly reduced PD-L1/PD-L2 expression on CD45+/CD31+ cells, and PD1⁺ cells were more numerous in the tumour mass. CTLA-4⁺ cell numbers were stable, but level of expression decreased. Similarly, CD47⁺ cells and expression were reduced. Consequently, angiogenesis normalization induced by ITPP is the mean to revert immunosuppression into an antitumor immune response. This brings a key adjuvant effect to improve the efficacy of chemo/radio/immunotherapeutic strategies for cancer treatment.

Nanomaterials for Antiangiogenic Therapies for Cancer: A Promising Tool for Personalized Medicine

Angiogenesis is one of the hallmarks of cancer. Several studies have shown that vascular endothelium growth factor (VEGF) plays a leading role in angiogenesis progression. Antiangiogenic medication has gained substantial recognition and is commonly administered in many forms of human cancer, leading to a rising interest in cancer therapy. However, this treatment method can lead to a deteriorating outcome of resistance, invasion, distant metastasis, and overall survival relative to its cytotoxicity. Furthermore, there are significant obstacles in tracking the efficacy of antiangiogenic treatments by incorporating positive biomarkers into clinical settings. These shortcomings underline the essential need to identify additional angiogenic inhibitors that target numerous angiogenic factors or to develop a new method for drug delivery of current inhibitors. The great benefits of nanoparticles are their potential, based on their specific properties, to be effective mechanisms that concentrate on the biological system and control various important functions. Among various therapeutic approaches, nanotechnology has emerged as a new strategy for treating different cancer types. This article attempts to demonstrate the huge potential for targeted nanoparticles and their molecular imaging applications. Notably, several nanoparticles have been developed and engineered to demonstrate antiangiogenic features. This nanomedicine could effectively treat a number of cancers using antiangiogenic therapies as an alternative approach. We also discuss the latest antiangiogenic and nanotherapeutic strategies and highlight tumor vessels and their microenvironments.

Five-dimensional quantitative low-dose Multitasking dynamic contrast- enhanced MRI: Preliminary study on breast cancer

PURPOSE

To develop a low-dose Multitasking DCE technique (LD-MT-DCE) for breast imaging, enabling dynamic T₁ mapping-based quantitative characterization of tumor blood flow and vascular properties with whole-breast coverage, a spatial resolution of 0.9 × 0.9 × 1.1 mm³ , and a temporal resolution of 1.4 seconds using a 20% gadolinium dose (0.02 mmol/kg).

METHODS

Magnetic resonance Multitasking was used to reconstruct 5D images with three spatial dimensions, one T₁ recovery dimension for dynamic T₁ quantification, and one DCE dimension for contrast kinetics. Kinetic parameters F p , v p , K trans , and v e were estimated from dynamic T₁ maps using the two-compartment exchange model. The LD-MT-DCE repeatability and agreement against standard-dose MT-DCE were evaluated in 20 healthy subjects. In 7 patients with triple-negative breast cancer, LD-MT-DCE image quality and diagnostic results were compared with that of standard-dose clinical DCE in the same imaging session. One-way unbalanced analysis of variance with Tukey test was performed to evaluate the statistical significance of the kinetic parameters between control and patient groups.

RESULTS

The LD-MT-DCE technique was repeatable, agreed with standard-dose MT-DCE, and showed excellent image quality. The diagnosis using LD-MT-DCE matched well with clinical results. The values of F p , v p , and K trans were significantly different between malignant tumors and normal breast tissue (P < .001, < .001, and < .001, respectively), and between malignant and benign tumors (P = .020, .003, and < .001, respectively).

CONCLUSION

The LD-MT-DCE technique was repeatable and showed excellent image quality and equivalent diagnosis compared with standard-dose clinical DCE. The estimated kinetic parameters were capable of differentiating between normal breast tissue and benign and malignant tumors.

Synthesis and evaluation of 68Ga-labeled dimeric cNGR peptide for PET imaging of CD13 expression with ovarian cancer xenograft

Introduction: Previous studies have shown that peptides containing the asparagine-glycine-arginine (NGR) sequence can specifically bind to CD13 (aminopeptidase N) receptor, a tumor neovascular biomarker that is over-expressed on the surface of angiogenic blood vessels and various tumor cells, and it plays an important role in angiogenesis and tumor progression. In the present study, we aimed to evaluate the efficacy of a gallium-68 (⁶⁸Ga)-labeled dimeric cyclic NGR (cNGR) peptide as a new molecular probe that binds to CD13 in vitro and in vivo.

Materials and Methods: A dimeric cNGR peptide conjugated with 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA) was synthesized and labeled with ⁶⁸Ga. In vitro uptake and binding analyses of the ⁶⁸Ga- DOTA-c(NGR)₂ were performed in two ovarian tumor cell lines, ES2 and SKOV3, which had different CD13 expression patterns. An in vivo biodistribution study was performed in normal mice, and micro positron emission tomography (PET) imaging was conducted in nude mice bearing ES2 and SKOV3 tumors.

Results:⁶⁸Ga-DOTA-c(NGR)₂ was prepared with high radiochemical purity (>95%), and it was stable both in saline at room temperature and in bovine serum at 37°C for 3 h. In vitro studies showed that the uptake of ⁶⁸Ga-DOTA-c(NGR)₂ in ES2 cells was higher compared with SKOV3 cells, and such uptake could be blocked by the cold DOTA-c(NGR)₂. Biodistribution studies demonstrated that ⁶⁸Ga-DOTA-c(NGR)₂ was rapidly cleared from blood and mainly excreted from the kidney. MicroPET imaging of ES2 tumor xenografts showed the focal uptake of ⁶⁸Ga-DOTA-c(NGR)₂ in tumors from 1 to 1.5 h post-injection. The high-contrast tumor visualization occurred at 1 h, corresponding to the highest tumor/background ratio of 10.30±0.26. The CD13-specific tumor targeting of the ⁶⁸Ga-DOTA-c(NGR)₂ was further supported by the reduced uptake of the probe in ES2 tumors by co-injection of the unlabeled cold peptide. In SKOV3 tumor models, the tumor was not obviously visible under the same imaging conditions.

Conclusions:⁶⁸Ga-DOTA-c(NGR)₂ was easily synthesized, and it showed favorable CD13-specific targeting ability by in vitro data and microPET imaging with ovarian cancer xenografts. Collectively, ⁶⁸Ga-DOTA-c(NGR)₂ might be a potential PET imaging probe for non-invasive evaluation of the CD13 receptor expression in tumors.

Obesity and Cancer Metastasis: Molecular and Translational Perspectives

Obesity is a modern health problem that has reached pandemic proportions. It is an established risk factor for carcinogenesis, however, evidence for the contribution of adipose tissue to the metastatic behavior of tumors is also mounting. Over 90% of cancer mortality is attributed to metastasis and metastatic tumor cells must communicate with their microenvironment for survival. Many of the characteristics observed in obese adipose tissue strongly mirror the tumor microenvironment. Thus in the case of prostate, pancreatic and breast cancer and esophageal adenocarcinoma, which are all located in close anatomical proximity to an adipose tissue depot, the adjacent fat provides an ideal microenvironment to enhance tumor growth, progression and metastasis. Adipocytes provide adipokines, fatty acids and other soluble factors to tumor cells whilst immune cells infiltrate the tumor microenvironment. In addition, there are emerging studies on the role of the extracellular vesicles secreted from adipose tissue, and the extracellular matrix itself, as drivers of obesity-induced metastasis. In the present review, we discuss the major mechanisms responsible for the obesity-metastatic link. Furthermore, understanding these complex mechanisms will provide novel therapies to halt the tumor-adipose tissue crosstalk with the ultimate aim of inhibiting tumor progression and metastatic growth.

Adaptive response of resistant cancer cells to chemotherapy

Despite advances in cancer therapeutics and the integration of personalized medicine, the development of chemoresistance in many patients remains a significant contributing factor to cancer mortality. Upon treatment with chemotherapeutics, the disruption of homeostasis in cancer cells triggers the adaptive response which has emerged as a key resistance mechanism. In this review, we summarize the mechanistic studies investigating the three major components of the adaptive response, autophagy, endoplasmic reticulum (ER) stress signaling, and senescence, in response to cancer chemotherapy. We will discuss the development of potential cancer therapeutic strategies in the context of these adaptive resistance mechanisms, with the goal of stimulating research that may facilitate the development of effective cancer therapy.

Cancer stem cell secretome in the tumor microenvironment: a key point for an effective personalized cancer treatment

Cancer stem cells (CSCs) represent a tumor subpopulation responsible for tumor metastasis and resistance to chemo- and radiotherapy, ultimately leading to tumor relapse. As a consequence, the detection and eradication of this cell subpopulation represent a current challenge in oncology medicine. CSC phenotype is dependent on the tumor microenvironment (TME), which involves stem and differentiated tumor cells, as well as different cell types, such as mesenchymal stem cells, endothelial cells, fibroblasts and cells of the immune system, in addition to the extracellular matrix (ECM), different in composition to the ECM in healthy tissues. CSCs regulate multiple cancer hallmarks through the interaction with cells and ECM in their environment by secreting extracellular vesicles including exosomes, and soluble factors such as interleukins, cytokines, growth factors and other metabolites to the TME. Through these factors, CSCs generate and activate their own tumor niche by recruiting stromal cells and modulate angiogenesis, metastasis, resistance to antitumor treatments and their own maintenance by the secretion of different factors such as IL-6, VEGF and TGF-ß. Due to the strong influence of the CSC secretome on disease development, the new antitumor therapies focus on targeting these communication networks to eradicate the tumor and prevent metastasis, tumor relapse and drug resistance. This review summarizes for the first time the main components of the CSC secretome and how they mediate different tumor processes. Lastly, the relevance of the CSC secretome in the development of more precise and personalized antitumor therapies is discussed.

Phase I, Pharmacogenomic, Drug Interaction Study of Sorafenib and Bevacizumab in Combination with Paclitaxel in Patients with Advanced Refractory Solid Tumors

VEGF blockade does not uniformly result in clinical benefit. We evaluated safety, dose-limiting toxicities (DLT), recommended phase II dose (RP2D), antitumor efficacy, and exploratory biomarkers including pharmacogenomics and pharmacokinetics with sorafenib, bevacizumab, and paclitaxel in patients with refractory cancers. The study had a "3 + 3" design, using paclitaxel 80 mg/m² every week for 3 weeks, in every 4 week cycles, bevacizumab 5 mg/kg every 2 weeks, and sorafenib 200 or 400 mg twice a day, 5 or 7 days/week (5/7, 7/7). The MTD cohort was expanded. Twenty-seven patients enrolled in 3 cohorts: sorafenib 200 mg twice a day 5/7, 200 mg twice a day 7/7, and 400 mg twice a day 5/7. DLTs were grade 3 neutropenia >7 days (cohort 1, 1), grade 3 hypertension (cohort 2, 1), grade 3 hand-foot skin reaction (HFSR; cohort 3, 2). MTD was sorafenib 200 mg twice a day 7/7. Six DLTs occurred in cohort 2 expansion: grade 3 HFSR (2), grade 2 HFSR with sorafenib delay >7 days (2), grade 4 cerebrovascular accident (1), grade 3 neutropenia >7 days (1). RP2D was sorafenib 200 mg twice a day 5/7. Most patients (62%) dose reduced sorafenib to 200 mg daily 5/7 after a median 3 (range, 2-17) cycles. Response rates were 48% overall (27) and 64% for ovarian cancers (14). VEGF-A-1154AA and -7TT recessive homozygous genotypes conferred worse overall survival versus alternative genotypes (7 vs. 22 months). Intermittent, low-dose sorafenib (200 mg twice a day 5/7) combined with bevacizumab and paclitaxel was tolerable and had high antitumor efficacy in patients with refractory cancer (NCT00572078).

Therapeutic paradigm of dual targeting VEGF and PDGF for effectively treating FGF-2 off-target tumors

FGF-2 displays multifarious functions in regulation of angiogenesis and vascular remodeling. However, effective drugs for treating FGF-2⁺ tumors are unavailable. Here we show that FGF-2 modulates tumor vessels by recruiting NG2⁺ pricytes onto tumor microvessels through a PDGFRβ-dependent mechanism. FGF-2⁺ tumors are intrinsically resistant to clinically available drugs targeting VEGF and PDGF. Surprisingly, dual targeting the VEGF and PDGF signaling produces a superior antitumor effect in FGF-2⁺ breast cancer and fibrosarcoma models. Mechanistically, inhibition of PDGFRβ ablates FGF-2-recruited perivascular coverage, exposing anti-VEGF agents to inhibit vascular sprouting. These findings show that the off-target FGF-2 is a resistant biomarker for anti-VEGF and anti-PDGF monotherapy, but a highly beneficial marker for combination therapy. Our data shed light on mechanistic interactions between various angiogenic and remodeling factors in tumor neovascularization. Optimization of antiangiogenic drugs with different principles could produce therapeutic benefits for treating their resistant off-target cancers.

Anti-VEGF therapy has many limitations that might be resolved by using combination treatment approaches. Here, the authors demonstrate that the dual-targeting of VEGF and PDGF is required for targeting resistant FGF2+ tumors which depend on the recruitment of pericytes on tumor microvessels.

The hypertensive effect of sorafenib is abolished by sildenafil

Background

Contrasting to the well documented tyrosine kinase inhibitor (TKI)-induced hypertension, little is known on their intrinsic vasomotor effects. We investigated the vasomotor effects of sorafenib, a widely used multikinase inhibitor in the treatment of hepatocellular and renal cell carcinoma and tested the hypothesis that sildenafil, a phosphodiesterase-5 (PDE-5) inhibitor, could represent a pharmacological strategy for the treatment of TKI-induced hypertension.

Methods

Concentration-response curves of sorafenib were constructed in endothelium-intact or denuded precontracted rat aorta, in the presence or absence of several inhibitors. Acute intravenous effects of sorafenib on arterial blood pressure were also investigated in anaesthetized rats. Finally, rats were chronically treated with sorafenib during 4 weeks in the presence and absence of sildenafil.

Results

In endothelium intact aortic ring, sorafenib induced a potent concentration-dependent relaxation of precontracted rat aorta. Removal of the endothelium shifted the concentration-response curve of sorafenib to the right and significantly reduced its maximal effects, demonstrating that sorafenib-induced vasorelaxation is endothelium-dependent and endothelium-independent. Inhibition of the different pathways implicated in the endothelium-dependent and independent vasorelaxation revealed that the endothelium-dependent effects of sorafenib result mainly from the activation of prostaglandin and the nitric oxide (NO) pathways. The endothelium-independent vasodilatory effects of sorafenib may result mainly from the activation of Na/K-ATPase and soluble guanylate cyclase. These vasodilatory effects observed in vitro were confirmed by the decrease in arterial blood pressure observed during acute administrations of sorafenib in anesthetized rats. Finally, and most importantly, we report here for the first time that chronic administration of sorafenib in rats induced an increase in SBP that was abolished by sildenafil.

Conclusion

The multikinase inhibitor sorafenib induced in vitro vasorelaxation of large conductance artery, primary by activating soluble guanylate cyclase. Its chronic administration led to arterial blood hypertension that was counteracted by a PDE-5 inhibitor, sildenafil. Our results suggest that targeting the cGMP pathway including NO signalling might be an interesting pharmacological strategy for the treatment of TKI-induced hypertension.

State of the art and up-and-coming angiogenesis inhibitors for ovarian cancer

Angiogenesis inhibitors have clearly shown activity in ovarian cancer in various settings; however, preliminary data did not reflect significant survival benefit. Bevacizumab has been extensively studied and is approved for use in ovarian malignancy. However, the efficacy of bevacizumab is modest and most treated patients eventually develop acquired resistance, which highlights the need for new targeted therapies and/or combination strategies. Newer therapies are being evaluated and their role of these newer therapies is upcoming and promising. Recent research focuses on the role of this drug group in frontline, maintenance and recurrent settings. Combination of PARP inhibitors with angiogenesis inhibitors has recently shown to improved survival rates. Potential strategies need to be devised for selecting patients most likely to benefit from such therapy.

HOX Transcript Antisense RNA HOTAIR Abrogates Vasculogenic Mimicry by Targeting the AngiomiR-204/FAK Axis in Triple Negative Breast Cancer Cells

HOX transcript antisense RNA (HOTAIR) is an oncogenic long non-coding RNA frequently overexpressed in cancer. HOTAIR can enhance the malignant behavior of tumors by sponging microRNAs with tumor suppressor functions. Vasculogenic mimicry is a hypoxia-activated process in which tumor cells form three-dimensional (3D) channel-like networks, resembling endothelial blood vessels, to obtain nutrients. However, the role of HOTAIR in vasculogenic mimicry and the underlying mechanisms are unknown in human cancers. In the current study, we investigated the relevance of HOTAIR in hypoxia-induced vasculogenic mimicry in metastatic MDA-MB-231 and invasive Hs-578t triple negative breast cancer cells. Analysis of The Cancer Genome Atlas (TCGA) database using cBioPortal confirmed that HOTAIR was upregulated in clinical breast tumors relative to normal mammary tissues. Our quantitative RT-PCR assays showed a significant increase in HOTAIR levels after 48 h hypoxia relative to normoxia in breast cancer cell lines. Remarkably, knockdown of HOTAIR significantly abolished the hypoxia-induced vasculogenic mimicry which was accompanied by a reduction in the number of 3D channel-like networks and branch points. Likewise, HOTAIR silencing leads to reduced cell migration abilities of cancer cells. Bioinformatic analysis predicted that HOTAIR has a potential binding site for tumor suppressor miR-204. Luciferase reporter assays confirmed that HOTAIR is a competitive endogenous sponge of miR-204. Congruently, forced inhibition of HOTAIR in cells resulted in augmented miR-204 levels in breast cancer cells. Further bioinformatic analysis suggested that miR-204 can bind to the 3′ untranslated region of focal adhesion kinase 1 (FAK) transcript involved in cell migration. Western blot and luciferase reporter assays confirmed that FAK is a novel target of miR-204. Finally, silencing of HOTAIR resulted in low levels of cytoplasmic FAK protein and alterations in the organization of cellular cytoskeleton and focal adhesions. In summary, our results showed, for the first time, that HOTAIR mitigates cell migration and vasculogenic mimicry by targeting the miR-204/FAK axis in triple negative breast cancer cells.

Neutrophils expressing lysyl oxidase-like 4 protein are present in colorectal cancer liver metastases resistant to anti-angiogenic therapy

Colorectal cancer liver metastases (CRCLM) that present with a replacement histopathological growth pattern (HGP) are resistant to neoadjuvant anti-angiogenic therapy. Surrogate biomarkers are not available to preoperatively identify patients with these tumors. Here we identify differentially expressed genes between CRCLM with a replacement HGP and those with a desmoplastic HGP using RNA sequencing. We demonstrate that LOXL4 is transcriptionally upregulated in replacement HGP CRCLM compared with desmoplastic HGP CRCLM and the adjacent normal liver. Interestingly, lysyl oxidase-like 4 (LOXL4) protein was expressed by neutrophils present in the tumor microenvironment in replacement HGP CRCLM. We further demonstrate that LOXL4 expression is higher in circulating neutrophils of cancer patients compared with healthy control patients and its expression can be induced by stimulation with lipopolysaccharide and TNF-α. Our study is the first to show the expression of LOXL4 in neutrophils and reveals the potential for LOXL4-expressing neutrophils to support the replacement HGP phenotype and to serve as a surrogate biomarker for this subtype of CRCLM. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Spatial Characterization of Tumor Perfusion Properties from 3D DCE-US Perfusion Maps are Early Predictors of Cancer Treatment Response

There is a need for noninvasive repeatable biomarkers to detect early cancer treatment response and spare non-responders unnecessary morbidities and costs. Here, we introduce three-dimensional (3D) dynamic contrast enhanced ultrasound (DCE-US) perfusion map characterization as inexpensive, bedside and longitudinal indicator of tumor perfusion for prediction of vascular changes and therapy response. More specifically, we developed computational tools to generate perfusion maps in 3D of tumor blood flow, and identified repeatable quantitative features to use in machine-learning models to capture subtle multi-parametric perfusion properties, including heterogeneity. Models were developed and trained in mice data and tested in a separate mouse cohort, as well as early validation clinical data consisting of patients receiving therapy for liver metastases. Models had excellent (ROC-AUC > 0.9) prediction of response in pre-clinical data, as well as proof-of-concept clinical data. Significant correlations with histological assessments of tumor vasculature were noted (Spearman R > 0.70) in pre-clinical data. Our approach can identify responders based on early perfusion changes, using perfusion properties correlated to gold-standard vascular properties.

Upregulation of adipocyte enhancer-binding protein 1 in endothelial cells promotes tumor angiogenesis in colorectal cancer

Tumor angiogenesis is an important therapeutic target in colorectal cancer (CRC). We aimed to identify novel genes associated with angiogenesis in CRC. Using RNA sequencing analysis in normal and tumor endothelial cells (TECs) isolated from primary CRC tissues, we detected frequent upregulation of adipocyte enhancer‐binding protein 1 (AEBP1) in TECs. Immunohistochemical analysis revealed that AEBP1 is upregulated in TECs and stromal cells in CRC tissues. Quantitative RT‐PCR analysis showed that there is little or no AEBP1 expression in CRC cell lines, but that AEBP1 is well expressed in vascular endothelial cells. Levels of AEBP1 expression in Human umbilical vein endothelial cells (HUVECs) were upregulated by tumor conditioned medium derived from CRC cells or by direct coculture with CRC cells. Knockdown of AEBP1 suppressed proliferation, migration, and in vitro tube formation by HUVECs. In xenograft experiments, AEBP1 knockdown suppressed tumorigenesis and microvessel formation. Depletion of AEBP1 in HUVECs downregulated a series of genes associated with angiogenesis or endothelial function, including aquaporin 1 (AQP1) and periostin (POSTN), suggesting that AEBP1 might promote angiogenesis through regulation of those genes. These results suggest that upregulation of AEBP1 contributes to tumor angiogenesis in CRC, which makes AEBP1 a potentially useful therapeutic target.

TSP-1 as a novel biological marker of tumor vasculature normalization in colon carcinoma induced by Endostar

Blood vessels in tumors often exhibit abnormal morphology and function, which promotes the growth, metastasis and resistance of tumors to conventional therapies. Therefore, vascular normalization is an emerging strategy to enhance the effectiveness of radiotherapy and chemotherapy when used in combination; however, there is a lack of evidence regarding the optimal schedule for the co-administration of anti-angiogenic and chemotherapeutic drugs. Scheduling treatment is important as the period for normalization is transient, also known as the ‘time window’; however, no biomarker has been identified to detect this window. In the present study, recombinant human endostatin (rhES) was employed as an anti-angiogenic agent in xenograft tumor tissue in mice. Following rhES or control (saline) treatment, the density and integrity of tumor vessels were detected by immunofluorescence staining for cluster of differentiation 31 and α-smooth muscle actin; the level of hypoxia in tumor tissue was examined by immunohistochemistry with pimonidazole; the necrotic area was evaluated by hematoxylin and eosin staining; and the level of thrombospondin-1 (TSP-1) in plasma was tested by ELISA. The Cell Counting Kit-8 assay was also used to evaluate the effect of rhES on the proliferation of colon carcinoma SW620 cells. A ‘time window’ normalized vasculature was determined between day 4 and 6 following rhES treatment, and accompanied by a decrease in hypoxia in tumor tissue. Decreasing plasma TSP-1 levels were consistent with changes in vascular morphology and hypoxia, which exhibited features of normalization. In addition, rhES had no effect on the proliferation of SW620 cells, suggesting that the reduction in TSP-1 was associated with increased oxygen content during vascular normalization, rather than inhibited cell proliferation. In conclusion, TSP-1 may be a potential biomarker for predicting the normalization window of colon cancer vessels.

Eosinophil and lymphocyte counts predict bevacizumab response and survival in recurrent glioblastoma

Background

There is a lack of biomarkers to identify glioblastoma (GBM) patients who may benefit from specific salvage therapies, such as the anti-angiogenic agent bevacizumab. We hypothesized that circulating blood counts may serve as biomarkers for treatment response and clinical outcomes.

Methods

Complete blood counts, clinical data, and radiographic information were collected retrospectively from 84 recurrent GBM patients receiving bevacizumab (10 mg/kg every 2 weeks). Significant biomarkers were categorized into quartiles and the association with clinical outcomes was assessed using the Kaplan–Meier method.

Results

The median treatment duration and survival on bevacizumab (OS-A) was 88 and 192 days, respectively. On multivariate analysis, MGMT promoter methylation (hazard ratio [HR] 0.504, P = .031), increases in red blood cells (HR 0.496, P = .035), and increases in eosinophils (HR 0.048, P = .054) during treatment predicted improved OS-A. Patients in the first and fourth quartiles of eosinophil changes had a 12-month survival probability of 5.6% and 41.2% (P < .0001), respectively. Treatment response was associated with increases in eosinophil counts (P = .009) and improved progression-free survival (P = .013). On multivariate analysis, increases in lymphocyte counts among responders predicted improved OS-A (HR 0.389, P = .044). Responders in the first and fourth quartiles of lymphocyte changes had a 12-month survival probability of 0% and 44.4% (P = .019), respectively. Changes in platelet counts differed before and after radiographic response (P = .014).

Conclusions

Changes in circulating eosinophil, lymphocyte, and platelet counts may predict treatment response and clinical outcomes in patients with recurrent GBM receiving bevacizumab.