Silencing or fueling metastasis with VEGF inhibitors: antiangiogenesis revisited

Halofuginone-guided nano-local therapy: Nano-thermosensitive hydrogels for postoperative metastatic canine mammary carcinoma with scar removal

In female dogs, the highest morbidity and mortality rates cancer are the result of mammary adenocarcinoma, which presents with metastases in the lung. Other than early surgical removal, however, no special methods are available to treat mammary adenocarcinoma. Because human breast cancer and canine mammary carcinoma share clinical characteristics and heterogeneity, the canine model is a suitable spontaneous tumor model for breast cancer in humans. In this study, the physical swelling method was used to prepare halofuginone-loaded D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) polymer micelles nano-thermosensitive hydrogels (HTPM-gel). Furthermore, HTPM-gel was investigated via characterization, morphology, properties such as swelling experiment and in vitro release with reflecting its splendid nature. Moreover, HTPM-gel was further examined its capability to anti-proliferation, anti-migration, and anti-invasion. Ultimately, HTPM-gel was investigated for its in vivo anticancer activity in the post-operative metastatic and angiogenic canine mammary carcinoma. HTPM-gel presented spherical under transmission electron microscope (TEM) and represented grid structure under scanning electron microscope (SEM), with hydrodynamic diameter (HD) of 20.25 ± 2.5 nm and zeta potential (ZP) of 15.10 ± 1.82 mV. Additionally, HTPM-gel own excellent properties comprised of pH-dependent swelling behavior, sustained release behavior. To impede the migration, invasion, and proliferation of CMT-U27 cells, we tested the efficacy of HTPM-gel. Evaluation of in vivo anti-tumor efficacy demonstrates HTPM-gel exhibit a splendid anti-metastasis and anti-angiogenic ability, with exhibiting ideal biocompatibility. Notably, HTPM-gel also inhibited the scar formation in the healing process after surgery. In summary, HTPM-gel exhibited anti-metastasis and anti-angiogenic and scar repair features. According to the results of this study, HTPM-gel has encouraging clinical potential to treat tumors with multifunctional hydrogel.

LncRNA IL21-AS1 facilitates tumour progression by enhancing CD24-induced phagocytosis inhibition and tumorigenesis in ovarian cancer

CD24 is overexpressed in various tumours and considered a regulator of cell migration, invasion, and proliferation. Recent studies have found that CD24 on ovarian cancer (OC) and triple-negative breast cancer cells interacts with the inhibitory receptor sialic-acid-binding Ig-like lectin 10 (Siglec-10) on tumour-associated macrophages (TAMs) to inhibit phagocytosis by macrophages. Because of its multiple roles in regulating the immune response and tumorigenesis, CD24 is a very promising therapeutic target. However, the regulatory mechanism of CD24 in OC remains unclear. Here, we found that the long noncoding RNA (lncRNA) IL21-AS1, which was upregulated in OC, inhibited macrophage-mediated phagocytosis and promoted OC cell proliferation and apoptosis inhibition. More importantly, after IL21-AS1 knockdown, a significant survival advantage was observed in mice engrafted with tumours. Mechanistically, we identified IL21-AS1 as a hypoxia-induced lncRNA. Moreover, IL21-AS1 increased HIF1α-induced CD24 expression under hypoxic conditions. In parallel, we found that IL21-AS1 acted as a competing endogenous RNA (ceRNA) for miR-561-5p to regulate CD24 expression. Finally, IL21-AS1 increased CD24 expression in OC and facilitated OC progression. Our findings provide a molecular basis for the regulation of CD24, thus highlighting a potential strategy for targeted treatment of OC.

Overexpression of YAP confers radioresistance to esophageal cancer by altering the tumor microenvironment

This study aimed to investigate the role of yes-associated protein (YAP) in the radiotherapy sensitivity of esophageal squamous cell carcinoma (ESCC). The clonogenic ability of ESCC cells was reduced after YAP silencing and radiotherapy. Overexpression of YAP promoted cell survival and had a synergistic effect with the hypoxic microenvironment. YAP was found to directly regulate hypoxia-inducible factor 1α (HIF-1α). Bioinformatics analysis revealed the involvement of YAP in modulating the tumor immune microenvironment. Inhibition of YAP expression reduced myeloid-derived suppressor cells (MDSCs) and influenced the immunosuppressive state, leading to radio resistance. These findings provide insights into the YAP-HIF-1α interaction and support YAP as a potential target for enhancing radiotherapy sensitivity in esophageal cancer.

Associations between HIFs and tumor immune checkpoints: mechanism and therapy

Hypoxia, which activates a variety of signaling pathways to enhance tumor cell growth and metabolism, is among the primary features of tumor cells. Hypoxia-inducible factors (HIFs) have a substantial impact on a variety of facets of tumor biology, such as epithelial-mesenchymal transition, metabolic reprogramming, angiogenesis, and improved radiation resistance. HIFs induce hypoxia-adaptive responses in tumor cells. Many academics have presented preclinical and clinical research targeting HIFs in tumor therapy, highlighting the potential applicability of targeted HIFs. In recent years, the discovery of numerous pharmacological drugs targeting the regulatory mechanisms of HIFs has garnered substantial attention. Additionally, HIF inhibitors have attained positive results when used in conjunction with traditional oncology radiation and/or chemotherapy, as well as with the very promising addition of tumor immunotherapy. Immune checkpoint inhibitors (CPIs), which are employed in a range of cancer treatments over the past decades, are essential in tumor immunotherapy. Nevertheless, the use of immunotherapy has been severely hampered by tumor resistance and treatment-related toxicity. According to research, HIF inhibitors paired with CPIs may be game changers for multiple malignancies, decreasing malignant cell plasticity and cancer therapy resistance, among other things, and opening up substantial new pathways for immunotherapy drug development. The structure, activation mechanisms, and pharmacological sites of action of the HIF family are briefly reviewed in this work. This review further explores the interactions between HIF inhibitors and other tumor immunotherapy components and covers the potential clinical use of HIF inhibitors in combination with CPIs.

Travelling under pressure - hypoxia and shear stress in the metastatic journey

Cancer cell invasion, intravasation and survival in the bloodstream are early steps of the metastatic process, pivotal to enabling the spread of cancer to distant tissues. Circulating tumor cells (CTCs) represent a highly selected subpopulation of cancer cells that tamed these critical steps, and a better understanding of their biology and driving molecular principles may facilitate the development of novel tools to prevent metastasis. Here, we describe key research advances in this field, aiming at describing early metastasis-related processes such as collective invasion, shedding, and survival of CTCs in the bloodstream, paying particular attention to microenvironmental factors like hypoxia and mechanical stress, considered as important influencers of the metastatic journey.

Efficacy and Safety of Anlotinib-Containing Regimens in Advanced Non-Small Cell Lung Cancer: A Real-World Study

Purpose

Anlotinib is widely used in the clinical treatment of non-small cell lung cancer (NSCLC), alone or in combination with other anticancer drugs. The aim of this study was to investigate the real-world efficacy and safety of anlotinib-containing regimens.

Patients and Methods

Confirmed advanced NSCLC patients who had received anlotinib alone or in combination were enrolled. An overall analysis of the efficacy and safety of anlotinib was performed in all patients, and then subgroup analysis was used to further compare the efficacy between anlotinib monotherapy and combination therapy. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were ADR, ORR, and DCR.

Results

A total of 240 patients were included. The overall median PFS was 8.5 months (95% confidence interval [CI]: 7.1-9.9 months). Anlotinib treatment regimens (monotherapy or combination therapy) and whether they received previous antiangiogenesis were associated with PFS. Anlotinib plus immunotherapy achieved longer PFS than anlotinib monotherapy (median PFS: 10.5 vs 6.5 months, p=0.007). Stratification analysis showed the PFS of anlotinib plus immunotherapy was significantly longer in male, adenocarcinoma, <=65 years old, patients stage IV, EGFR wild type, with extrathoracic metastasis, performance status scores ≥2, the first-line treatment, patients with a history of hypertension and no previous antiangiogenesis than anlotinib monotherapy. The median PFS of anlotinib plus chemotherapy, targeted therapy was slightly longer than anlotinib alone (respectively, 10.5 vs 6.5 months, p=0.095; 9.5 vs 6.5 months, p=0.177). Adverse reactions were mostly mild and acceptable, with hypertension being the most common.

Conclusion

Anlotinib is effective and tolerable in advanced NSCLC patients. Immunotherapy combination with anlotinib significantly improved PFS. The efficacy of anlotinib may be impaired by previous antiangiogenic therapy, which can be investigated in further studies.

Glioma-derived small extracellular vesicles induce pericyte-phenotype transition of glioma stem cells under hypoxic conditions

BACKGROUND

Glioblastoma (GBM) is the most common and lethal primary brain tumor characterized by extensive vascularization. Anti-angiogenic therapy for this cancer offers the possibility of universal efficacy. However, preclinical and clinical studies suggest that anti-VEGF drug such as Bevacizumab actively promotes tumor invasion, which ultimately leads to a therapy-resistant and recurrent phenotype of GBMs. Whether Bevacizumab can improve survival over chemotherapy alone remains debated. Herein, we emphasized the importance of small extracellular vesicles (sEVs) internalization by glioma stem cells (GSCs) in giving rise to the failure of anti-angiogenic therapy in the treatment of GBMs and discovered a specific therapeutic target for this damaging disease.

METHODS

To experimentally prove that hypoxia condition promotes the release of GBM cells-derived sEVs, which could be taken up by the surrounding GSCs, we used an ultracentrifugation strategy to isolate GBM-derived sEVs under hypoxic or normoxic conditions, performed bioinformatics analysis and multidimensional molecular biology experiments, and established a xenograft mouse model.

RESULTS

The internalization of sEVs by GSCs was proved to promote tumor growth and angiogenesis through the pericyte-phenotype transition. Hypoxia-derived sEVs could efficiently deliver TGF-β1 to GSCs, thus resulting in the activation of the TGF-β signaling pathway and the consequent pericyte-phenotype transition. Specifically targeting GSC-derived pericyte using Ibrutinib can reverse the effects of GBM-derived sEVs and enhance the tumor-eradicating effects when combined with Bevacizumab.

CONCLUSION

This present study provides a new interpretation of the failure of anti-angiogenic therapy in the non-operative treatment of GBMs and discovers a promising therapeutic target for this intractable disease.

UBXN2A suppresses the Rictor-mTORC2 signaling pathway, an established tumorigenic pathway in human colorectal cancer

The mTORC2 pathway plays a critical role in promoting tumor progression in human colorectal cancer (CRC). The regulatory mechanisms for this signaling pathway are only partially understood. We previously identified UBXN2A as a novel tumor suppressor protein in CRCs and hypothesized that UBXN2A suppresses the mTORC2 pathway, thereby inhibiting CRC growth and metastasis. We first used murine models to show that haploinsufficiency of UBXN2A significantly increases colon tumorigenesis. Induction of UBXN2A reduces AKT phosphorylation downstream of the mTORC2 pathway, which is essential for a plethora of cellular processes, including cell migration. Meanwhile, mTORC1 activities remain unchanged in the presence of UBXN2A. Mechanistic studies revealed that UBXN2A targets Rictor protein, a key component of the mTORC2 complex, for 26S proteasomal degradation. A set of genetic, pharmacological, and rescue experiments showed that UBXN2A regulates cell proliferation, apoptosis, migration, and colon cancer stem cells (CSCs) in CRC. CRC patients with a high level of UBXN2A have significantly better survival, and high-grade CRC tissues exhibit decreased UBXN2A protein expression. A high level of UBXN2A in patient-derived xenografts and tumor organoids decreases Rictor protein and suppresses the mTORC2 pathway. These findings provide new insights into the functions of an ubiquitin-like protein by inhibiting a dominant oncogenic pathway in CRC.

Breast tumors interfere with endothelial TRAIL at the premetastatic niche to promote cancer cell seeding

Endothelial cells (ECs) grant access of disseminated cancer cells to distant organs. However, the molecular players regulating the activation of quiescent ECs at the premetastatic niche (PMN) remain elusive. Here, we find that ECs at the PMN coexpress tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its cognate death receptor 5 (DR5). Unexpectedly, endothelial TRAIL interacts intracellularly with DR5 to prevent its signaling and preserve a quiescent vascular phenotype. In absence of endothelial TRAIL, DR5 activation induces EC death and nuclear factor κB/p38-dependent EC stickiness, compromising vascular integrity and promoting myeloid cell infiltration, breast cancer cell adhesion, and metastasis. Consistently, both down-regulation of endothelial TRAIL at the PMN by proangiogenic tumor-secreted factors and the presence of the endogenous TRAIL inhibitors decoy receptor 1 (DcR1) and DcR2 favor metastasis. This study discloses an intracrine mechanism whereby TRAIL blocks DR5 signaling in quiescent endothelia, acting as gatekeeper of the vascular barrier that is corrupted by the tumor during cancer cell dissemination.

Deciphering endothelial heterogeneity in health and disease at single-cell resolution: progress and perspectives

Endothelial cells (ECs) constitute the inner lining of vascular beds in mammals and are crucial for homeostatic regulation of blood vessel physiology, but also play a key role in pathogenesis of many diseases, thereby representing realistic therapeutic targets. However, it has become evident that ECs are heterogeneous, encompassing several subtypes with distinct functions, which makes EC targeting and modulation in diseases challenging. The rise of the new single-cell era has led to an emergence of studies aimed at interrogating transcriptome diversity along the vascular tree, and has revolutionized our understanding of EC heterogeneity from both a physiological and pathophysiological context. Here, we discuss recent landmark studies aimed at teasing apart the heterogeneous nature of ECs. We cover driving (epi)genetic, transcriptomic, and metabolic forces underlying EC heterogeneity in health and disease, as well as current strategies used to combat disease-enriched EC phenotypes, and propose strategies to transcend largely descriptive heterogeneity towards prioritization and functional validation of therapeutically targetable drivers of EC diversity. Lastly, we provide an overview of the most recent advances and hurdles in single EC OMICs.

In situ forming oxygen/ROS-responsive niche-like hydrogel enabling gelation-triggered chemotherapy and inhibition of metastasis

Though the development of the diverse hypoxia-activated prodrugs (HAPs) has made great progresses in the last several decades, current cancer therapy based on HAPs still suffers many obstacles, e.g., poor therapeutic outcome owing to hard deep reaching to hypoxic region, and the occurrence of metastasis due to hypoxia. Inspired by engineered niches, a novel functional chitosan polymer (CS-FTP) is synthesized for construction of a hydrogel-based bio-niche (CS-FTP-gel) in aiming at remodeling tumor hypoxic microenvironment. The CS-FTP polymers are crosslinked to form a niche-like hydrogel via enzyme-mediated oxygen-consumable dimerization after injected into tumor, in which a HAP (i.e., AQ4N) could be physically encapsulated, resulting in enhanced tumor hypoxia to facilitate AQ4N-AQ4 toxic transformation for maximizing efficacy of chemotherapy. Furthermore, Pazopanib (PAZ) conjugated onto the CS backbone via ROS-sensitive linker undergoes a stimuli-responsive release behavior to promote antiangiogenesis for tumor starvation, eventually contributing to the inhibition of lung metastasis and synergistic action with AQ4N-based chemotherapy for an orthotopic 4T1 breast tumor model. This study provides a promising strategy for hypoxia-based chemotherapy and demonstrates an encouraging clinical potential for multifunctional hydrogel applicable for antitumor treatment.

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CS-FTP shows enzyme-mediated hypoxia-inducible gelation and reactive oxygen species (ROS)-responsive drug release.

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CS-FTP gel formed intratumorally can be used as a bio-niche to enhance tumor hypoxic microenvironment.

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In vivo PET/CT directly monitors the tumor hypoxia changes and confirm the ability of CS-FTP to enhance tumor hypoxia.

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Oxygen-consumable gelation of ROS-responsive CS-FTP triggers chemotherapy and starvation therapy for antimetastasis.

Downstream Targets of VHL/HIF-α Signaling in Renal Clear Cell Carcinoma Progression: Mechanisms and Therapeutic Relevance

The clear cell variant of renal cell carcinoma (ccRCC) is the most common renal epithelial malignancy and responsible for most of the deaths from kidney cancer. Patients carrying inactivating mutations in the Von Hippel-Lindau (VHL) gene have an increased proclivity to develop several types of tumors including ccRCC. Normally, the Hypoxia Inducible Factor alpha (HIF-α) subunits of the HIF heterodimeric transcription factor complex are regulated by oxygen-dependent prolyl-hydroxylation, VHL-mediated ubiquitination and proteasomal degradation. Loss of pVHL function results in elevated levels of HIF-α due to increased stability, leading to RCC progression. While HIF-1α acts as a tumor suppressor, HIF-2α promotes oncogenic potential by driving tumor progression and metastasis through activation of hypoxia-sensitive signaling pathways and overexpression of HIF-2α target genes. One strategy to suppress ccRCC aggressiveness is directed at inhibition of HIF-2α and the associated molecular pathways leading to cell proliferation, angiogenesis, and metastasis. Indeed, clinical and pre-clinical data demonstrated the effectiveness of HIF-2α targeted therapy in attenuating ccRCC progression. This review focuses on the signaling pathways and the involved genes (cyclin D, c-Myc, VEGF-a, EGFR, TGF-α, GLUT-1) that confer oncogenic potential downstream of the VHL-HIF-2α signaling axis in ccRCC. Discussed as well are current treatment options (including receptor tyrosine kinase inhibitors such as sunitinib), the medical challenges (high prevalence of metastasis at the time of diagnosis, refractory nature of advanced disease to current treatment options), scientific challenges and future directions.

The cooperative folding of annexin A2 relies on a transient nonnative intermediate

Annexins (Anxs) are a family of highly homologous proteins that bind and aggregate lipid vesicles in the presence of calcium. All members of the family contain a variable N-terminus determining specific functions, followed by a conserved core region responsible for the general calcium-dependent lipid-binding property. The core structure consists of four homologous domains (DI-DIV), each consisting of a right-handed super-helix of five α-helices. We present data from a combination of site-directed mutagenesis, NMR, and circular dichroism showing that the G25-D34 region of the N-terminus as well as the contacts between residues D38A, R63A, and Q67A of AnxA2-DI are crucial for the autonomous folding and stability of DI of AnxA2. However, we also show that the folding of the full-length protein is very robust in that mutations and truncations that disrupted the folding of AnxA2-DI did not abolish the folding of full-length AnxA2, only lowering its thermal stability. This robustness of the folding of full-length AnxA2 is likely to be mediated by the existence of at least one transient nonnative intermediate as suggested by our kinetic data using stopped-flow fluorescence experiments. We also show that hydrophobic amino acids in AnxA2-DI involved in interfacial contacts with AnxA2-DIV are important for the cooperative folding and stability of the full-length protein. Mutating all of the V57E-V98R-G101Y residues in AnxA2-DI did not affect the folding of the domain, only its stability, but prevented the cooperative folding of the full-length protein. Our collective results favor a highly cooperative and robust folding process mediated by alternative intermediate steps. Since AnxA2 is a multifunctional protein involved in several steps of the progression of cell transformation, these data on structure and folding pathways are therefore crucial to designing anticancer drugs targeting AnxA2.

Targeting Tumor Angiogenesis with the Selective VEGFR-3 Inhibitor EVT801 in Combination with Cancer Immunotherapy

The receptor tyrosine kinase VEGFR-3 plays a crucial role in cancer-induced angiogenesis and lymphangiogenesis, promoting tumor development and metastasis. Here, we report the novel VEGFR-3 inhibitor EVT801 that presents a more selective and less toxic profile than two major inhibitors of VEGFRs (i.e., sorafenib and pazopanib). As monotherapy, EVT801 showed a potent antitumor effect in VEGFR-3–positive tumors, and in tumors with VEGFR-3–positive microenvironments. EVT801 suppressed VEGF-C–induced human endothelial cell proliferation in vitro and tumor (lymph)angiogenesis in different tumor mouse models. In addition to reduced tumor growth, EVT801 decreased tumor hypoxia, favored sustained tumor blood vessel homogenization (i.e., leaving fewer and overall larger vessels), and reduced important immunosuppressive cytokines (CCL4, CCL5) and myeloid-derived suppressor cells (MDSC) in circulation. Furthermore, in carcinoma mouse models, the combination of EVT801 with immune checkpoint therapy (ICT) yielded superior outcomes to either single treatment. Moreover, tumor growth inhibition was inversely correlated with levels of CCL4, CCL5, and MDSCs after treatment with EVT801, either alone or combined with ICT. Taken together, EVT801 represents a promising anti(lymph)angiogenic drug for improving ICT response rates in patients with VEGFR-3 positive tumors.

Significance:

The VEGFR-3 inhibitor EVT801 demonstrates superior selectivity and toxicity profile than other VEGFR-3 tyrosine kinase inhibitors. EVT801 showed potent antitumor effects in VEGFR-3–positive tumors, and tumors with VEGFR-3–positive microenvironments through blood vessel homogenization, and reduction of tumor hypoxia and limited immunosuppression. EVT801 increases immune checkpoint inhibitors’ antitumor effects.

How does plasticity of migration help tumor cells to avoid treatment: Cytoskeletal regulators and potential markers

Tumor shrinkage as a result of antitumor therapy is not the only and sufficient indicator of treatment success. Cancer progression leads to dissemination of tumor cells and formation of metastases - secondary tumor lesions in distant organs. Metastasis is associated with acquisition of mobile phenotype by tumor cells as a result of epithelial-to-mesenchymal transition and further cell migration based on cytoskeleton reorganization. The main mechanisms of individual cell migration are either mesenchymal, which depends on the activity of small GTPase Rac, actin polymerization, formation of adhesions with extracellular matrix and activity of proteolytic enzymes or amoeboid, which is based on the increase in intracellular pressure caused by the enhancement of actin cortex contractility regulated by Rho-ROCK-MLCKII pathway, and does not depend on the formation of adhesive structures with the matrix, nor on the activity of proteases. The ability of tumor cells to switch from one motility mode to another depending on cell context and environmental conditions, termed migratory plasticity, contributes to the efficiency of dissemination and often allows the cells to avoid the applied treatment. The search for new therapeutic targets among cytoskeletal proteins offers an opportunity to directly influence cell migration. For successful treatment it is important to assess the likelihood of migratory plasticity in a particular tumor. Therefore, the search for specific markers that can indicate a high probability of migratory plasticity is very important.

Antibody variable region engineering for improving cancer immunotherapy

The efficacy and specificity of conventional monoclonal antibody (mAb) drugs in the clinic require further improvement. Currently, the development and application of novel antibody formats for improving cancer immunotherapy have attracted much attention. Variable region-retaining antibody fragments, such as antigen-binding fragment (Fab), single-chain variable fragment (scFv), bispecific antibody, and bi/trispecific cell engagers, are engineered with humanization, multivalent antibody construction, affinity optimization and antibody masking for targeting tumor cells and killer cells to improve antibody-based therapy potency, efficacy and specificity. In this review, we summarize the application of antibody variable region engineering and discuss the future direction of antibody engineering for improving cancer therapies.

The measurement and modification of hypoxia in colorectal cancer: overlooked but not forgotten

Tumour hypoxia is the inevitable consequence of a tumour's rapid growth and disorganized, inefficient vasculature. The compensatory mechanisms employed by tumours, and indeed the absence of oxygen itself, hinder the ability of all treatment modalities. The clinical consequence is poorer overall survival, disease-free survival, and locoregional control. Recognizing this, clinicians have been attenuating the effect of hypoxia, primarily with hypoxic modification or with hypoxia-activated pro-drugs, and notable success has been demonstrated. However, in the case of colorectal cancer (CRC), there is a general paucity of knowledge and evidence surrounding the measurement and modification of hypoxia, and this is possibly due to the comparative inaccessibility of such tumours. We specifically review the role of hypoxia in CRC and focus on the current evidence for the existence of hypoxia in CRC, the majority of which originates from indirect positron emission topography imaging with hypoxia selective radiotracers; the evidence correlating CRC hypoxia with poorer oncological outcome, which is largely based on the measurement of hypoxia inducible factor in correlation with clinical outcome; the evidence of hypoxic modification in CRC, of which no direct evidence exists, but is reflected in a number of indirect markers; the prognostic and monitoring implications of accurate CRC hypoxia quantification and its potential in the field of precision oncology; and the present and future imaging tools and technologies being developed for the measurement of CRC hypoxia, including the use of blood-oxygen-level-dependent magnetic resonance imaging and diffuse reflectance spectroscopy.

A Phase II Study Evaluating the Safety and Efficacy of Sunitinib Malate in Combination With Weekly Paclitaxel Followed by Doxorubicin and Daily Oral Cyclophosphamide Plus G-CSF as Neoadjuvant Chemotherapy for Locally Advanced or Inflammatory Breast Cancer

INTRODUCTION

Neoadjuvant chemotherapy is standard treatment for locally advanced breast cancer (LABC) or inflammatory breast cancer (IBC). We hypothesized that adding sunitinib, a tyrosine kinase inhibitor with antitumor and antiangiogenic activity, to an anthracycline and taxane regimen would improve pathologic complete response (pCR) rates to a prespecified endpoint of 45% in patients with HER2-negative LABC or IBC.

METHODS

We conducted a multicenter, phase II trial of neoadjuvant sunitinib with paclitaxel (S+T) followed by doxorubicin and cyclophosphamide plus G-CSF for patients with HER2-negative LABC or IBC. Patients received sunitinib 25 mg PO daily with paclitaxel 80 mg/m² IV weekly ×12 followed by doxorubicin 24 mg/m² IV weekly + cyclophosphamide 60 mg/m² PO daily with G-CSF support. Response was evaluated using pCR in the breast and the CPS + EG score (clinical-pathologic scoring + estrogen receptor [ER] and grade).

RESULTS

Seventy patients enrolled, and 66 were evaluable for efficacy. Eighteen patients (27%) had pCR in the breast (10 had ER⁺ disease and 8 had triple-negative disease). When defining response as pCR and/or CPS + EG score ≤2, 31 (47%) were responders. In pateints with ER positive disease, 23 (64%) were responders. The most common toxicities were cytopenias and fatigue.

CONCLUSIONS

Neoadjuvant S+T followed by AC+G-CSF was safe and tolerable in LABC and IBC. The study did not meet the prespecified endpoint for pCR; however, 47% were responders using pCR and/or CPS + EG score ≤2. ER positive patients had the highest response rate (64%). The addition of sunitinib to neoadjuvant chemotherapy may provide promising incremental benefit for patients with ER positive LABC.

Transgelin Contributes to a Poor Response of Metastatic Renal Cell Carcinoma to Sunitinib Treatment

Renal cell carcinoma (RCC) represents about 2-3% of all cancers with over 400,000 new cases per year. Sunitinib, a vascular endothelial growth factor tyrosine kinase receptor inhibitor, has been used mainly for first-line treatment of metastatic clear-cell RCC with good or intermediate prognosis. However, about one-third of metastatic RCC patients do not respond to sunitinib, leading to disease progression. Here, we aim to find and characterize proteins associated with poor sunitinib response in a pilot proteomics study. Sixteen RCC tumors from patients responding (8) vs. non-responding (8) to sunitinib 3 months after treatment initiation were analyzed using data-independent acquisition mass spectrometry, together with their adjacent non-cancerous tissues. Proteomics analysis quantified 1996 protein groups (FDR = 0.01) and revealed 27 proteins deregulated between tumors non-responding vs. responding to sunitinib, representing a pattern of deregulated proteins potentially contributing to sunitinib resistance. Gene set enrichment analysis showed an up-regulation of epithelial-to-mesenchymal transition with transgelin as one of the most significantly abundant proteins. Transgelin expression was silenced by CRISPR/Cas9 and RNA interference, and the cells with reduced transgelin level exhibited significantly slower proliferation. Our data indicate that transgelin is an essential protein supporting RCC cell proliferation, which could contribute to intrinsic sunitinib resistance.

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.

STAT3 phosphorylation is required for the HepaCAM-mediated inhibition of castration-resistant prostate cancer cell viability and metastasis

BACKGROUND

Castration-resistant prostate cancer (CRPC) is an advanced disease that is difficult to treat, the mechanism of it is unclear. This study illustrated the function of hepatocyte cell adhesion molecule (HepaCAM) on CRPC cell viability and metastasis.

METHODS

The expression of HepaCAM and p-STAT3 in CRPC tissues were determined by immunohistochemistry and western blot analysis. Cell Counting Kit-8 and colony formation assays were deployed to analyze the growth ability of CRPC cells following the adenovirus-mediated re-expression of HepaCAM. CRPC cell migration and invasion capacity were investigated by wound healing and Matrigel-coated transwell assays, respectively. The messenger RNA or protein levels of p-STAT3, CyclinD1, cMyc, MMP2, MMP9, and VEGF were determined by reverse transcription (RT) followed by quantitative real-time polymerase chain reaction (RT-qPCR), and western blot analysis after either HepaCAM re-expression alone or in combination with IL-22 treatment. A CRPC orthotopic xenograft mouse model was applied to investigate the functional effect of HepaCAM on the metastasis of CRPC cells to the lungs.

RESULTS

The expression levels of HepaCAM were decreased while those of p-STAT3 were elevated in CRPC cells compare with surrounding benign tissues (p < .001). The overexpression of HepaCAM in CRPC cells notably reduced proliferation, migration, and invasion by inhibiting the expression of p-STAT3, CyclinD1, cMyc, MMP2, MMP9, and VEGF (p < .05). In addition, the expression of HepaCAM significantly inhibited the IL-22/p-STAT3 axis and the metastasis of CRPC cells to the lungs.

CONCLUSIONS

Our data suggested that HepaCAM suppressed the viability of CRPC cells via the IL-22/p-STAT3 axis and inhibited the metastasis of CRPC cells from the prostate to the lungs (p < .05).

Targeting neovascularization and respiration of tumor grafts grown on chick embryo chorioallantoic membranes

Since growing tumors stimulate angiogenesis, via vascular endothelial growth factor (VEGF), angiogenesis inhibitors (AIs, blockers of the VEGF signaling pathway) have been introduced to cancer therapy. However, AIs often yielded only modest and short-lived gains in cancer patients and more invasive tumor phenotypes in animal models. Combining anti-VEGF strategies with lactate uptake blockers may boost both efficacy and safety of AIs. We assessed this hypothesis by using the ex ovo chorioallantoic membrane (CAM) assay. We show that AI-based monotherapy (Avastin®, AVA) increases tumor hypoxia in human CAM cancer cell xenografts and cell spread in human as well as canine CAM cancer cell xenografts. In contrast, combining AVA treatment with lactate importer MCT1 inhibitors (α-cyano-4-hydroxycinnamic acid (CHC) or AZD3965 (AZD)) reduced both tumor growth and cell dissemination of human and canine explants. Moreover, combining AVA+AZD diminished blood perfusion and tumor hypoxia in human explants. Thus, the ex ovo CAM assay as an easy, fast and cheap experimental setup is useful for pre-clinical cancer research. Moreover, as an animal-free experimental setup the CAM assay can reduce the high number of laboratory animals used in pre-clinical cancer research.

Role of PFKFB3 and PFKFB4 in Cancer: Genetic Basis, Impact on Disease Development/Progression, and Potential as Therapeutic Targets

Glycolysis is a crucial metabolic process in rapidly proliferating cells such as cancer cells. Phosphofructokinase-1 (PFK-1) is a key rate-limiting enzyme of glycolysis. Its efficiency is allosterically regulated by numerous substances occurring in the cytoplasm. However, the most potent regulator of PFK-1 is fructose-2,6-bisphosphate (F-2,6-BP), the level of which is strongly associated with 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase activity (PFK-2/FBPase-2, PFKFB). PFK-2/FBPase-2 is a bifunctional enzyme responsible for F-2,6-BP synthesis and degradation. Four isozymes of PFKFB (PFKFB1, PFKFB2, PFKFB3, and PFKFB4) have been identified. Alterations in the levels of all PFK-2/FBPase-2 isozymes have been reported in different diseases. However, most recent studies have focused on an increased expression of PFKFB3 and PFKFB4 in cancer tissues and their role in carcinogenesis. In this review, we summarize our current knowledge on all PFKFB genes and protein structures, and emphasize important differences between the isoenzymes, which likely affect their kinase/phosphatase activities. The main focus is on the latest reports in this field of cancer research, and in particular the impact of PFKFB3 and PFKFB4 on tumor progression, metastasis, angiogenesis, and autophagy. We also present the most recent achievements in the development of new drugs targeting these isozymes. Finally, we discuss potential combination therapies using PFKFB3 inhibitors, which may represent important future cancer treatment options.

VEGFR2-targeted antibody fused with IFN mut regulates the tumor microenvironment of colorectal cancer and exhibits potent anti-tumor and anti-metastasis activity

Although interferon α (IFNα) and anti-angiogenesis antibodies have shown appropriate clinical benefit in the treatment of malignant cancer, they are deficient in clinical applications. Previously, we described an anti-vascular endothelial growth factor receptor 2 (VEGFR2)-IFNα fusion protein named JZA01, which showed increased in vivo half-life and reduced side effects compared with IFNα, and it was more effective than the anti-VEGFR2 antibody against tumors. However, the affinity of the IFNα component of the fusion protein for its receptor-IFNAR1 was decreased. To address this problem, an IFNα-mutant fused with anti-VEGFR2 was designed to produce anti-VEGFR2-IFNαmut, which was used to target VEGFR2 with enhanced anti-tumor and anti-metastasis efficacy. Anti-VEGFR2-IFNαmut specifically inhibited proliferation of tumor cells and promoted apoptosis. In addition, anti-VEGFR2-IFNαmut inhibited migration of colorectal cancer cells and invasion by regulating the PI3K-AKT-GSK3β-snail signal pathway. Anti-VEGFR2-IFNαmut showed superior anti-tumor efficacy with improved tumor microenvironment (TME) by enhancing dendritic cell maturation, dendritic cell activity, and increasing tumor-infiltrating CD8+ T cells. Thus, this study provides a novel approach for the treatment of metastatic colorectal cancer, and this design may become a new approach to cancer immunotherapy.

Effects of Sorafenib, a Tyrosin Kinase Inhibitor, on Adrenocortical Cancer

The lack of an effective medical treatment for adrenocortical carcinoma (ACC) has prompted the search for better treatment protocols for ACC neoplasms. Sorafenib, a tyrosine kinase inhibitor has exhibited effectiveness in the treatment of different human tumors. Therefore, the aim of this study was to understand the mechanism through which sorafenib acts on ACC, especially since treatment with sorafenib alone is sometimes unable to induce a long-lasting antiproliferative effect in this tumor type. The effects of sorafenib were tested on the ACC cell line H295R by evaluating cell viability, apoptosis and VEGF receptor signaling which was assessed by analyzing VE-cadherin and β-catenin complex formation. We also tested sorafenib on an in vitro 3D cell culture model using the same cell line. Apoptosis was observed after sorafenib treatment, and coimmunoprecipitation data suggested that the drug prevents formation VEGFR-VE-cadherin and β-catenin proteins complex. These results were confirmed both by ultrastructural analysis and by a 3D model where we observed a disaggregation of spheres into single cells, which is a crucial event that represents the first step of metastasis. Our findings suggest that although sorafenib induces apoptotic cell death a small portion of cells survive the treatment and have characteristics of a malignancy. Based on our data we recommend against the use of sorafenib in patients with ACC.

Targeting angiogenesis for liver cancer: Past, present, and future

Liver cancer, mostly hepatocellular carcinoma (HCC), is the second leading cause of cancer mortality globally. Most patients were diagnosed at an advanced stage, and systemic therapy is the standard of care. All the approved systemic therapies for HCC are molecular targeted therapies with anti-angiogenic effects targeting the vascular endothelial growth factor signaling pathway. Sorafenib and lenvatinib are the first-line treatment, and regorafenib, ramucirumab, and cabozantinib are second-line treatment options. Although anti-PD-1 antibodies, including nivolumab and pembrolizumab, demonstrated promising anti-tumor effects as monotherapy for advanced HCC in phase II clinical trials, both failed in phase III studies. Anti-angiogenic treatment remains the backbone of systemic therapy for HCC. In this review, we summarized the approved anti-angiogenic medicines and discussed the potential strategies to improve the efficacy of anti-angiogenic therapy, including combination therapy with other treatments, and discussed the approaches to overcome the drawbacks of anti-angiogenic therapies.

B55α/PP2A Limits Endothelial Cell Apoptosis During Vascular Remodeling: A Complementary Approach To Disrupt Pathological Vessels?

RATIONALE

How endothelial cells (ECs) migrate and form an immature vascular plexus has been extensively studied. Yet, mechanisms underlying vascular remodeling remain poorly established. A better understanding of these processes may lead to the design of novel therapeutic strategies complementary to current angiogenesis inhibitors.

OBJECTIVE

Starting from our previous observations that PP2A (protein phosphatase 2) regulates the HIF (hypoxia-inducible factor)/PHD-2 (prolyl hydroxylase 2)-constituted oxygen machinery, we hypothesized that this axis could play an important role during blood vessel formation, tissue perfusion, and oxygen restoration.

METHODS AND RESULTS

We show that the PP2A regulatory subunit B55α is at the crossroad between vessel pruning and vessel maturation. Blood vessels with high B55α counter cell stress conditions and thrive for stabilization and maturation. When B55α is inhibited, ECs cannot cope with cell stress and undergo apoptosis, leading to massive pruning of nascent blood vessels. Mechanistically, we found that the B55α/PP2A complex restrains PHD-2 activity, promoting EC survival in a HIF-dependent manner, and furthermore dephosphorylates p38, altogether protecting ECs against cell stress occurring, for example, during the onset of blood flow. In tumors, EC-specific B55α deficiency induces pruning of immature-like tumor blood vessels resulting in delayed tumor growth and metastasis, without affecting nonpathological vessels. Consistently, systemic administration of a pan-PP2A inhibitor disrupts vascular network formation and tumor progression in vivo without additional effects on B55α-deficient vessels.

CONCLUSIONS

Our data underline a unique role of the B55α/PP2A phosphatase complex in vessel remodeling and suggest the use of PP2A-inhibitors as potent antiangiogenic drugs targeting specifically nascent blood vessels with a mode-of-action complementary to VEGF-R (vascular endothelial growth factor receptor)-targeted therapies. Graphical Abstract: A graphical abstract is available for this article.

Zebrafish In Vivo Models of Cancer and Metastasis

Metastasis, the dispersal of cancer cells from a primary tumor to secondary sites within the body, is the leading cause of cancer-related death. Animal models have been an indispensable tool to investigate the complex interactions between the cancer cells and the tumor microenvironment during the metastatic cascade. The zebrafish (Danio rerio) has emerged as a powerful vertebrate model for studying metastatic events in vivo. The zebrafish has many attributes including ex-utero development, which facilitates embryonic manipulation, as well as optically transparent tissues, which enables in vivo imaging of fluorescently labeled cells in real time. Here, we summarize the techniques which have been used to study cancer biology and metastasis in the zebrafish model organism, including genetic manipulation and transgenesis, cell transplantation, live imaging, and high-throughput compound screening. Finally, we discuss studies using the zebrafish, which have complemented and benefited metastasis research.

Basic and Therapeutic Aspects of Angiogenesis Updated

All organisms growing beyond the oxygen diffusion limit critically depend on a functional vasculature for survival. Yet blood vessels are far more than passive, uniform conduits for oxygen and nutrient supply. A remarkable organotypic heterogeneity is brought about by tissue-specific differentiated endothelial cells (lining the blood vessels' lumen) and allows blood vessels to deal with organ-specific demands for homeostasis. On the flip side, when blood vessels go awry, they promote life-threatening diseases characterized by endothelial cells inappropriately adopting an angiogenic state (eg, tumor vascularization) or becoming dysfunctional (eg, diabetic microvasculopathies), calling respectively for antiangiogenic therapies and proangiogenic/vascular regenerative strategies. In solid tumors, despite initial enthusiasm, growth factor-based (mostly anti-VEGF [vascular endothelial growth factor]) antiangiogenic therapies do not sufficiently live up to the expectations in terms of efficiency and patient survival, in part, due to intrinsic and acquired therapy resistance. Tumors cunningly deploy alternative growth factors than the ones targeted by the antiangiogenic therapies to reinstigate angiogenesis or revert to other ways of securing blood flow, independently of the targeted growth factors. In trying to alleviate tissue ischemia and to repair dysfunctional or damaged endothelium, local in-tissue administration of (genes encoding) proangiogenic factors or endothelial (stem) cells harnessing regenerative potential have been explored. Notwithstanding evaluation in clinical trials, these approaches are often hampered by dosing issues and limited half-life or local retention of the administered agents. Here, without intending to provide an all-encompassing historical overview, we focus on some recent advances in understanding endothelial cell behavior in health and disease and identify novel molecular players and concepts that could eventually be considered for therapeutic targeting.

Review of Pharmacological Strategies with Repurposed Drugs for Hereditary Hemorrhagic Telangiectasia Related Bleeding

The diagnosis of hereditary hemorrhagic telangiectasia (HHT) is based on the Curaçao criteria: epistaxis, telangiectases, arteriovenous malformations in internal organs, and family history. Genetically speaking, more than 90% of HHT patients show mutations in ENG or ACVRL1/ALK1 genes, both belonging to the TGF-β/BMP9 signaling pathway. Despite clear knowledge of the symptoms and genes of the disease, we still lack a definite cure for HHT, having just palliative measures and pharmacological trials. Among the former, two strategies are: intervention at "ground zero" to minimize by iron and blood transfusions in order to counteract anemia. Among the later, along the last 15 years, three different strategies have been tested: (1) To favor coagulation with antifibrinolytic agents (tranexamic acid); (2) to increase transcription of ENG and ALK1 with specific estrogen-receptor modulators (bazedoxifene or raloxifene), antioxidants (N-acetylcysteine, resveratrol), or immunosuppressants (tacrolimus); and (3) to impair the abnormal angiogenic process with antibodies (bevacizumab) or blocking drugs like etamsylate, and propranolol. This manuscript reviews the main strategies and sums up the clinical trials developed with drugs alleviating HHT.

FABP5 promotes lymph node metastasis in cervical cancer by reprogramming fatty acid metabolism

Patients with cervical cancer (CCa) with lymph node metastasis (LNM) have an extremely poor prognosis. Elucidation of the molecular mechanisms underlying LNM may provide clinical therapeutic strategies for CCa. Upregulation of fatty acid-binding protein 5 (FABP5) expression in CCa tumours was demonstrated to positively correlate with LNM. However, the precise role and mechanisms of FABP5 in the LNM of CCa remain unknown. Methods: The diagnostic value of FABP5 as a predictor of LNM in CCa was evaluated in CCa tumour samples. The functional role of FABP5 and its upstream and downstream regulatory factors were investigated by gain-of-function and loss-of-function assays in vitro and in vivo. A mouse model of LNM was used to determine the effect of FABP5 on LNM and the therapeutic value of FABP5 targeting. Results: We demonstrated that FABP5 was markedly upregulated in CCa with LNM and correlated with poor prognosis. FABP5 protein was an independent predictor of LNM in a multivariate logistic analysis. Furthermore, FABP5 promoted epithelial-mesenchymal transition, lymphangiogenesis, and LNM by reprogramming fatty acid (FA) metabolism. Mechanistically, FABP5 promoted lipolysis and FA synthesis, which led to an increase in intracellular fatty acids (FAs) that activated NF-κB signalling, thus inducing LNM. Importantly, administration of orlistat, which attenuates FA metabolism reprogramming, inhibited FABP5-induced LNM in CCa. The pro-metastatic effect of FABP5 was reduced by miR-144-3p. Moreover, miR-144-3p was significantly downregulated and FABP5 was upregulated in CCa in a hypoxic microenvironment. Conclusion: Our findings highlight a FA metabolism-dependent mechanism of FABP5-induced LNM. Moreover, the expression and biological function of FABP5 can be regulated by miR-144-3p in hypoxia. Our study identifies FABP5 as a potential diagnostic biomarker and therapeutic target for LNM in CCa.

Increased autophagy/mitophagy levels in primary tumours of patients with pancreatic neuroendocrine neoplasms

BACKGROUND/AIMS

We assessed the levels of autophagy and mitophagy, that are linked to cancer development and drug resistance, in well differentiated pancreatic neuroendocrine neoplasms (PanNENs) and correlated them with clinico-pathological parameters.

METHODS

Fluorescent immunostaining for the autophagy markers LC3Β and p62/or LAMP1 was performed on 22 PanNENs and 11 controls of normal pancreatic tissues and validated through Western blotting. Autophagy quantitative scoring was generated for LC3B-positive puncta and analysed in relation to clinico-pathological parameters. TOMM20/LC3B qualitative assessment of mitophagy levels was undertaken by fluorescent immunostaining. The presence of autophagy/mitophagy was validated by transmission electron microscopy.

RESULTS

Autophagy levels (LC3B-positive puncta/cell) were discriminative for normal vs. NEN pancreatic tissue (p = 0.007). A significant association was observed between autophagy levels and tumour grade (Ki67 < 3% vs. Ki67 ≥ 3%; p = 0.021), but not functionality (p = 0.266) size (cut-off of 20 mm; p = 0.808), local invasion (p = 0.481), lymph node- (p = 0.849) and distant metastases (p = 0.699). Qualitative assessment of TOMM20/LC3B demonstrated strong mitophagy levels in PanNENs by fluorescent immunostaining as compared with normal tissue. Transmission electron microscopy revealed enhanced autophagy and mitophagy in PanNEN tissue. Response to molecular targeted therapies in metastatic cases (n = 4) did not reveal any patterns of association to autophagy levels.

CONCLUSIONS

Increased autophagy levels are present in primary tumours of patients with PanNENs and are partially attributed to upregulated mitophagy. Grade was the only clinico-pathological parameter associated with autophagy scores.

Phase I studies of vorinostat with ixazomib or pazopanib imply a role of antiangiogenesis-based therapy for TP53 mutant malignancies

We performed two phase I trials of the histone deacetylase inhibitor vorinostat combined with either the vascular endothelial growth factor inhibitor pazopanib (NCT01339871) or the proteasome inhibitor ixazomib (NCT02042989) in patients with metastatic TP53 mutant solid tumors. Both trials followed a 3 + 3 dose-escalation design allowing for a dose expansion cohort of up to 14 additional patients with a specific tumor type. Patients had to have a confirmed TP53 mutation to be enrolled in NCT02042989. Among patients enrolled in NCT01339871, TP53 mutation status was determined for those for whom tumor specimens were available. The results of NCT01339871 were reported previously. Common treatment-related adverse events in NCT02042989 included anemia, thrombocytopenia, fatigue, nausea, vomiting, and diarrhea. Compared with patients with metastatic TP53 hotspot mutant solid tumors who were treated with ixazomib and vorinostat (n = 59), those who were treated with pazopanib and vorinostat (n = 11) had a significantly higher rate of clinical benefit, defined as stable disease lasting ≥6 months or an objective response (3.4% vs. 45%; p < 0.001), a significantly longer median progression-free survival duration (1.7 months [95% confidence interval (CI), 1.1–2.3] vs. 3.5 months [95% CI, 1.7–5.2]; p = 0.002), and a longer median overall survival duration (7.3 months [95% CI, 4.8–9.8] vs. 12.7 months [95% CI, 7.1–18.3]; p = 0.24). Our two phase I trials provide preliminary evidence supporting the use of antiangiogenisis-based therapy in patients with metastatic TP53 mutant solid tumors, especially in those with metastatic sarcoma or metastatic colorectal cancer.

Toward Normalization of the Tumor Microenvironment for Cancer Therapy

The tumor microenvironment (TME) is a complex ecosystem, including blood vessels, immune cells, fibroblasts, extracellular matrix, cytokines, hormones, and so on. The TME differs from the normal tissue environment (NTE) in many aspects, such as tissue architecture, chronic inflammation, level of oxygen and pH, nutritional state of the cells, as well as tissue firmness. The NTE can inhibit the growth of cancer at the early tumorigenesis phase, whereas the TME promotes the growth of cancer in general, although it may have some anticancer effects. In particular, the TME plays a crucial role in the generation and maintenance of cancer stem cells, which lie at the root of cancer growth. Therefore, normalization of the TME to the NTE may inhibit cancer growth or improve cancer therapeutic efficiency. This review focuses on the recent emerging approaches for this normalization and the action mechanisms.

Calcium dobesilate reduces VEGF signaling by interfering with heparan sulfate binding site and protects from vascular complications in diabetic mice

Inhibiting vascular endothelial growth factor (VEGF) is a therapeutic option in diabetic microangiopathy. However, VEGF is needed at physiological concentrations to maintain glomerular integrity; complete VEGF blockade has deleterious effects on glomerular structure and function. Anti-VEGF therapy in diabetes raises the challenge of reducing VEGF-induced pathology without accelerating endothelial cell injury. Heparan sulfate (HS) act as a co-receptor for VEGF. Calcium dobesilate (CaD) is a small molecule with vasoprotective properties that has been used for the treatment of diabetic microangiopathy. Preliminary evidence suggests that CaD interferes with HS binding sites of fibroblast growth factor. We therefore tested the hypotheses that (1) CaD inhibits VEGF signaling in endothelial cells, (2) that this effect is mediated via interference between CaD and HS, and (3) that CaD ameliorates diabetic nephropathy in a streptozotocin-induced diabetic mouse model by VEGF inhibition. We found that CaD significantly inhibited VEGF₁₆₅-induced endothelial cell migration, proliferation, and permeability. CaD significantly inhibited VEGF₁₆₅-induced phosphorylation of VEGFR-2 and suppressed the activity of VEGFR-2 mediated signaling cascades. The effects of CaD in vitro were abrogated by heparin, suggesting the involvement of heparin-like domain in the interaction with CaD. In addition, VEGF₁₂₁, an isoform which does not bind to heparin, was not inhibited by CaD. Using the proximity ligation approach, we detected inhibition of interaction in situ between HS and VEGF and between VEGF and VEGFR-2. Moreover, CaD reduced VEGF signaling in mice diabetic kidneys and ameliorated diabetic nephropathy and neuropathy, suggesting CaD as a VEGF inhibitor without the negative effects of complete VEGF blockade and therefore could be useful as a strategy in treating diabetic nephropathy.

Low-dose docetaxel enhances the anti-tumour efficacy of a human umbilical vein endothelial cell vaccine

Our previous studies have indicated that human umbilical vein endothelial cell (HUVEC) vaccination appears to be a potentially promising anti-angiogenesis therapy, but the modest therapeutic anti-tumour efficiency limits its clinical use. This highlights the importance of identifying more potent therapeutic HUVEC vaccine strategies for clinical testing. In the present study, the immune-modulating doses of docetaxel (DOC) was combined with 1 × 10⁶ viable HUVECs as a means to enhance the therapeutic anti-tumour efficiency of the HUVEC vaccine. Our results demonstrated that 5 mg/kg DOC administrated prior to HUVEC vaccine could most effectively assist HUVEC vaccine to display a remarkable suppression of tumour growth and metastasis as wells as a prolongation of survival time in a therapeutic procedure. CD31 immunohistochemical analysis of the excised tumours confirmed a significant reduction in vessel density after treatment with the HUVEC vaccine with 5 mg/kg DOC. Additionally, an increased HUVEC-specific antibody level, activated CTLs and an elevated IFN-γ level in cultured splenocytes were revealed after treatment with HUVEC vaccine with 5 mg/kg DOC. Finally, 5 mg/kg DOC coupled with the HUVEC vaccine led to induction of significant increases in CD8⁺T cells and decrease in Tregs in the tumour microenvironment. Taken together, all the results verified that 5 mg/kg DOC could assist HUVEC vaccine to elicit strong HUVEC specific humoral and cellular responses, which could facilitate the HUVEC vaccine-mediated inhibition of cancer growth and metastasis. These findings provide the immunological rationale for the combined use of immune-modulating doses of DOC and HUVEC vaccines in patients with cancer.

Role of hypoxia in cancer therapy by regulating the tumor microenvironment

AIM

Clinical resistance is a complex phenomenon in major human cancers involving multifactorial mechanisms, and hypoxia is one of the key components that affect the cellular expression program and lead to therapy resistance. The present study aimed to summarize the role of hypoxia in cancer therapy by regulating the tumor microenvironment (TME) and to highlight the potential of hypoxia-targeted therapy.

METHODS

Relevant published studies were retrieved from PubMed, Web of Science, and Embase using keywords such as hypoxia, cancer therapy, resistance, TME, cancer, apoptosis, DNA damage, autophagy, p53, and other similar terms.

RESULTS

Recent studies have shown that hypoxia is associated with poor prognosis in patients by regulating the TME. It confers resistance to conventional therapies through a number of signaling pathways in apoptosis, autophagy, DNA damage, mitochondrial activity, p53, and drug efflux.

CONCLUSION

Hypoxia targeting might be relevant to overcome hypoxia-associated resistance in cancer treatment.

PTEN in Colorectal Cancer: Shedding Light on Its Role as Predictor and Target

Molecular assessment of colorectal cancer (CRC) is receiving growing attention, beyond RAS and BRAF, because of its influence on prognosis and prediction in cancer treatment. PTEN (phosphatase and tensin homologue), a tumor suppressor, regulating cell division and apoptosis, has been explored, and significant evidence suggests a role in cetuximab and panitumumab resistance linked to the epidermal growth factor receptor (EGFR) signal transduction pathway. Factors influencing PTEN activity should be analyzed to develop strategies to maximize the tumor suppressor role and to improve tumor response to cancer treatment. Therefore, an in-depth knowledge of the PI3K-Akt pathway—one of the major cancer survival pathways—and the role of PTEN—a major brake of this pathway—is essential in the era of precision medicine. The purpose of this literature review is to summarize the role of PTEN as a predictive factor and possible therapeutic target in CRC, focusing on ongoing studies and the possible implications in clinical practice.

TGF-β1 rs1800469 gene polymorphism in the development of cirrhosis & hepatocellular carcinoma in Pakistani HCV patients

Hepatocellular carcinoma (HCC) has been increasing among Pakistani males. Aim: The main objective of this study was to evaluate the role of TGF-β-1 gene polymorphism as a risk factor in chronic hepatitis C virus (HCV) infected HCC patients in Pakistan. Patients & methods: A total of 286 subjects were recruited into three different groups (Group I: 96 healthy controls, Group II: 96 HCV, Group III: 94 HCC). Results: A significant increase in genotype and allele frequencies of TGF-β-1 gene was observed in HCC, HCV with OR = 1.9; 95% CI: 1.275–2.871; p > 0.05, OR = 1.6; 95% CI: 1.12–2.51; p > 0.05 and OR = 1.7; 95% CI: 1.036–1.923; p > 0.05. Conclusion: A higher frequency of the TT genotype and T allele of the TGF-β-1 gene is observed in Pakistani HCV and HCC patients.

Identification of Potent VEGF Inhibitors for the Clinical Treatment of Glioblastoma, A Virtual Screening Approach

Vascular endothelial growth factor (VEGF) expression could be found in all glioblastomas. VEGF takes part in numerous changes including the endothelial cell proliferation, the vasculature of solid tumor: its survival invasion, and migration, chemotaxis of bone marrow-derived progenitor cells, vasodilation and vascular permeability. VEGF inhibition can be a smart therapeutic strategy because it is extremely specific and less toxic than cytotoxic therapy. To establish better inhibition of VEGF than the current inhibitors, present study approach is by molecular docking, virtual screening to illustrate the inhibitor with superior affinity against VEGF to have a cautious pharma profile. To retrieve the best established and high-affinity high affinity molecule, Molegro Virtual Docker software was executed. The high-affinity scoring compounds were subjected to further similarity search to retrieve the drugs with similar properties from pubchem database. The completion of virtual screening reveals that PubChem compound SCHEMBL1250485 (PubChem CID: 66965667) has the highest affinity. The study of the drug-likeness was verified using OSIRIS Property Explorer software which supported the virtual screened result. Further ADMET study and drug comparative study strongly prove the superiority of the new established inhibitor with lesser rerank score and toxicity. Overall, the new inhibitor has higher potential to stop the expression of VEGF in glioblastoma and positively can be further analysed through In vitro studies.

Topically Applied Etamsylate: A New Orphan Drug for HHT-Derived Epistaxis (Antiangiogenesis through FGF Pathway Inhibition)

Hereditary hemorrhagic telangiectasia (HHT) is a vascular dysplasia characterized by recurrent and spontaneous epistaxis (nose bleeds), telangiectases on skin and mucosa, internal organ arteriovenous malformations, and dominant autosomal inheritance. Mutations in Endoglin and ACVRL1 / ALK1 , genes mainly expressed in endothelium, are responsible in 90% of the cases for the pathology. These genes are involved in the transforming growth factor-β(TGF-β) signaling pathway. Epistaxis remains as one of the most common symptoms impairing the quality of life of patients, becoming life-threatening in some cases. Different strategies have been used to decrease nose bleeds, among them is antiangiogenesis. The two main angiogenic pathways in endothelial cells depend on vascular endothelial growth factor and fibroblast growth factor (FGF). The present work has used etamsylate, the diethylamine salt of the 2,5-dihydroxybenzene sulfonate anion, also known as dobesilate, as a FGF signaling inhibitor. In endothelial cells, in vitro experiments show that etamsylate acts as an antiangiogenic factor, inhibiting wound healing and matrigel tubulogenesis. Moreover, etamsylate decreases phosphorylation of Akt and ERK1/2. A pilot clinical trial (EudraCT: 2016–003982–24) was performed with 12 HHT patients using a topical spray of etamsylate twice a day for 4 weeks. The epistaxis severity score (HHT-ESS) and other pertinent parameters were registered in the clinical trial. The significant reduction in the ESS scale, together with the lack of significant side effects, allowed the designation of topical etamsylate as a new orphan drug for epistaxis in HHT (EMA/OD/135/18).

Two tales of Annexin A2 knock-down: One of compensatory effects by antisense RNA and another of a highly active hairpin ribozyme

Besides altering its own expression during cell transformation, Annexin A2 is upregulated during the progression of many cancer types and also plays key roles during viral infection and multiplication. Consequently, there has been great interest in Annexin A2 as a potential drug target. The successful design of efficient in vivo delivery systems constitutes an obstacle in full exploitation of antisense and RNA-cleaving technologies for the knock-down of specific targets. Efficiency is dependent on the method of delivery and accessibility of the target. Here, hairpin ribozymes and an antisense RNA against rat annexin A2 mRNA were tested for their efficiencies in a T7-driven coupled transcription/translation system. The most efficient ribozyme and antisense RNA were subsequently inserted into a retroviral vector under the control of a tRNA promoter, in a cassette inserted between retroviral Long Terminal Repeats for stable insertion into host DNA. The Phoenix package system based on defective retroviruses was used for virus-mediated gene transfer into PC12 cells. Cells infected with the ribozyme-containing particles died shortly after infection. However, the same ribozyme showed a very high catalytic effect in vitro in cell lysates, explained by its loose hinge helix 2 region. This principle can be transferred to other ribozymes, such as those designed to cleave the guide RNA in the CRISPR/Cas9 technology, as well as to target specific viral RNAs. Interestingly, efficient down-regulation of the expression of Annexin A2 by the antisense RNA resulted in up-regulation of Annexin A7 as a compensatory effect after several cell passages. Indeed, compensatory effects have previously been observed during gene knock-out, but not during knock-down of protein expression. This highlights the problems in interpreting the phenotypic effects of knocking down the expression of a protein. In addition, these data are highly relevant when considering the effects of the CRISPR/Cas9 approach.

Limitations of Anti-Angiogenic Treatment of Tumors

Clinical trials using anti-vascular endothelial growth factor /(VEGF) molecules induce a modest improvement in overall survival, measurable in weeks to just a few months, and tumors respond differently to these agents. In this review article, we have exposed some tumor characteristics and processes that may impair the effectiveness of anti-angiogenic approaches, including genotypic changes on endothelial cells, the vascular normalization phenomenon, and the vasculogenic mimicry. The usage of anti-angiogenic molecules leads to hypoxic tumor microenvironment which enhances tumor invasiveness. The role of tumor-infiltrating cells, including tumor associated macrophages and fibroblasts (TAMs and TAFs) in the therapeutic response to anti-angiogenic settings was also highlighted. Finally, among the new therapeutic approaches to target tumor vasculature, anti-PD-1 or anti-PD-L1 therapy sensitizing and prolonging the efficacy of anti-angiogenic therapy, have been discussed.

Evaluation of soluble carbonic anhydrase IX as predictive marker for efficacy of bevacizumab: A biomarker analysis from the geparquinto phase III neoadjuvant breast cancer trial

We analyzed the predictive potential of pretreatment soluble carbonic anhydrase IX levels (sCAIX) for the efficacy of bevacizumab in the phase III neoadjuvant GeparQuinto trial. sCAIX was determined by enzyme-linked immunosorbent assay (ELISA). Correlations between sCAIX and pathological complete response (pCR), disease-free and overall survival (DFS, OS) were assessed with logistic and Cox proportional hazard regression models using bootstrapping for robust estimates and internal validation. 1,160 HER2-negative patient sera were analyzed, of whom 577 received bevacizumab. Patients with low pretreatment sCAIX had decreased pCR rates (12.1 vs. 20.1%, p = 0.012) and poorer DFS (adjusted 5-year DFS 71.4 vs. 80.5 months, p = 0.010) compared to patients with high sCAIX when treated with neoadjuvant chemotherapy (NCT). For patients with low sCAIX, pCR rates significantly improved upon addition of bevacizumab to NCT (12.1 vs. 20.4%; p = 0.017), which was not the case in patients with high sCAIX (20.1% for NCT vs. 17.0% for NCT-B, p = 0.913). When analyzing DFS we found that bevacizumab improved 5-year DFS for patients with low sCAIX numerically but not significantly (71.4 vs. 78.5 months; log rank 0.234). In contrast, addition of bevacizumab worsened 5-year DFS for patients with high sCAIX (81 vs. 73.6 months, log-rank 0.025). By assessing sCAIX levels we identified a patient cohort in breast cancer that is potentially undertreated with NCT alone. Bevacizumab improved pCR rates in this group, suggesting sCAIX is a predictive biomarker for bevacizumab with regards to treatment response. Our data also show that bevacizumab is not beneficial in patients with high sCAIX.

6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 and 4: A pair of valves for fine-tuning of glucose metabolism in human cancer

Background

Cancer cells favor the use of less efficient glycolysis rather than mitochondrial oxidative phosphorylation to metabolize glucose, even in oxygen-rich conditions, a distinct metabolic alteration named the Warburg effect or aerobic glycolysis. In adult cells, bifunctional 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase (PFKFB) family members are responsible for controlling the steady-state cytoplasmic levels of fructose-2,6-bisphosphate, which allosterically activates 6-phosphofructo-1-kinase, the key enzyme catalyzing the rate-limiting reaction of glycolysis. PFKFB3 and PFKFB4 are the two main isoenzymes overexpressed in various human cancers.

Scope of review

In this review, we summarize recent findings on the glycolytic and extraglycolytic roles of PFKFB3 and PFKFB4 in cancer progression and discuss potential therapies for targeting of PFKFB3 and PFKFB4.

Major conclusions

PFKFB3 has the highest kinase activity to shunt glucose toward glycolysis, whereas PFKFB4 has more FBPase-2 activity, redirecting glucose toward the pentose phosphate pathway, providing reducing power for lipid biosynthesis and scavenging reactive oxygen species. Co-expression of PFKFB3 and PFKFB4 provides sufficient glucose metabolism to satisfy the bioenergetics demand and redox homeostasis requirements of cancer cells. Various reversible post-translational modifications of PFKFB3 enable cancer cells to flexibly adapt glucose metabolism in response to diverse stress conditions. In addition to playing important roles in tumor cell glucose metabolism, PFKFB3 and PFKFB4 are widely involved in multiple biological processes, such as cell cycle regulation, autophagy, and transcriptional regulation in a non-glycolysis-dependent manner.

Screening for therapeutic targets of tumor angiogenesis signatures in 31 cancer types and potential insights

Tumor vessel normalization can increase pericyte coverage, perfusion efficiency and immune infiltration, while reducing hypoxia, vessel leakage, CTC and metastasis. In this study, we systemically presented the expression pattern of tumor angiogenesis gene signatures in 31 cancer types and its association with immune infiltration and cancer metastasis. Specifically, READ, COAD etc. have relatively similar expression patterns with low GPAGs and high PPAGs. Patients with this expression pattern may benefit from tumor vessel normalization. COAD was selected for further investigation and we found GPAG CXCL12 was downregulated while PPAG EPHB3 was overexpressed in COAD, which were further validated using two independent colon cancer dataset. Further study indicated that CXCL12 expression was positively correlated innate inflammation pathways such as NFκB and negatively correlated with metastasis, while EPHB3 had a reverse result. Moreover, CXCL12 was positively correlated with cancer immune infiltration while EPHB3 was negatively correlated with cancer immune infiltration. Besides, the association between CXCL12/EPHB3 and mutation/CNA landscape were also explored. We also discussed the potential application of gut microbiota in cancer treatment. In summary, blood vessel normalization could promote immune infiltration and repress cancer metastasis while immune cell infiltration can promote blood vessel normalization through a positive feedback loop.

Integrin-Mediated Delivery of Drugs and Nucleic Acids for Anti-Angiogenic Cancer Therapy: Current Landscape and Remaining Challenges

Angiogenesis, sprouting of new blood vessels from pre-existing vasculatures, plays a critical role in regulating tumor growth. Binding interactions between integrin, a heterodimeric transmembrane glycoprotein receptor, and its extracellular matrix (ECM) protein ligands govern the angiogenic potential of tumor endothelial cells. Integrin receptors are attractive targets in cancer therapy due to their overexpression on tumor endothelial cells, but not on quiescent blood vessels. These receptors are finding increasing applications in anti-angiogenic therapy via targeted delivery of chemotherapeutic drugs and nucleic acids to tumor vasculatures. The current article attempts to provide a retrospective account of the past developments, highlight important contemporary contributions and unresolved set-backs of this emerging field.

FABP4 as a key determinant of metastatic potential of ovarian cancer

The standard treatment for high-grade serous ovarian cancer is primary debulking surgery followed by chemotherapy. The extent of metastasis and invasive potential of lesions can influence the outcome of these primary surgeries. Here, we explored the underlying mechanisms that could increase metastatic potential in ovarian cancer. We discovered that FABP4 (fatty acid binding protein) can substantially increase the metastatic potential of cancer cells. We also found that miR-409-3p regulates FABP4 in ovarian cancer cells and that hypoxia decreases miR-409-3p levels. Treatment with DOPC nanoliposomes containing either miR-409-3p mimic or FABP4 siRNA inhibited tumor progression in mouse models. With RPPA and metabolite arrays, we found that FABP4 regulates pathways associated with metastasis and affects metabolic pathways in ovarian cancer cells. Collectively, these findings demonstrate that FABP4 is functionally responsible for aggressive patterns of disease that likely contribute to poor prognosis in ovarian cancer.