Off-tumor targets compromise antiangiogenic drug sensitivity by inducing kidney erythropoietin production

Tumor angiogenesis and anti-angiogenic therapy

ABSTRACT

Anti-angiogenic drugs (AADs), which mainly target the vascular endothelial growth factor-A signaling pathway, have become a therapeutic option for cancer patients for two decades. During this period, tremendous clinical experience of anti-angiogenic therapy has been acquired, new AADs have been developed, and the clinical indications for AAD treatment of various cancers have been expanded using monotherapy and combination therapy. However, improvements in the therapeutic outcomes of clinically available AADs and the development of more effective next-generation AADs are still urgently required. This review aims to provide historical and perspective views on tumor angiogenesis to allow readers to gain mechanistic insights and learn new therapeutic development. We revisit the history of concept initiation and AAD discovery, and summarize the up-to-date clinical translation of anti-angiogenic cancer therapy in this field.

Injectable thermosensitive hydrogel loading erythropoietin and FK506 alleviates gingival inflammation and promotes periodontal tissue regeneration

Background: Periodontitis is a chronic multifactorial inflammatory disease associated with dysbiotic plaque biofilms and characterized by progressive destruction of the tooth-supporting apparatus. Therefore, there is significant potential in the discovery of drugs that inhibit periodontal inflammatory responses and promote periodontal regeneration. Methods: In this study, we generated a periodontitis rat model to detect the effects of chitosan/β-sodium glycerophosphate (β-GP)/glycolic acid (GA) hydrogel carried Erythropoietin and FK506 (EPO-FK506-CS/β-GP/GA). A total of forty-eight male Wistar rats were used to establish the periodontitis model. Drug injection was administered every 3 days for a total of five times over a 2-week period. After a period of 2 weeks following implantation, the rats underwent anesthesia, and a section of their maxillae encompassing the maxillary first and second molars, along with the alveolar bone, was obtained. micro-CT scanning, histopathology, immunohistochemistry and reverse transcription-quantitative PCR (RT-qPCR) assays were performed. Meanwhile, ELISA assay was performed to detect the levels of inflammatory mediators (TNF-α, IL-6 and IL-1β). Results: The synthesis and characterization of EPO-FK506-CS/β-GP/GA revealed that the hydrogel has stability and sustained release of drugs. The application of FK506+EPO was found to significantly enhance new bone formation in the defect area, as evidenced by the results of HE staining. Additionally, the use of FK506+EPO in the treated groups led to a notable increase in the density of alveolar bone, as observed through micro-CT analysis, when compared to the Model group. EPO-FK506-CS/β-GP/GA hydrogel exhibited notable efficacy in modulating inflammatory mediators (TNF-α, IL-6 and IL-1β). Furthermore, the osteoinductive properties of the EPO-FK506-CS/β-GP/GA hydrogel were extensive, as evidenced by a significant upregulation in the expression of key markers (Collagen I, Runx2, OPN, and OCN) associated with osteoblastic differentiation. Conclusion: Taken together, EPO-FK506-CS/β-GP/GA hydrogel alleviates gingival inflammation and promotes periodontal tissue regeneration in the periodontitis.

ENO1 expression and Erk phosphorylation in PDAC and their effects on tumor cell apoptosis in a hypoxic microenvironment

OBJECTIVE

Hypoxia is an important feature of pancreatic ductal adenocarcinoma (PDAC). Previously, we found that hypoxia promotes ENO1 expression and PDAC invasion. However, the underlying molecular mechanism was remains unclear.

METHODS

The relationship between ENO1 expression and clinicopathological characteristics was analyzed in 84 patients with PADC. The effects of CoCl₂-induced hypoxia and ENO1 downregulation on the apoptosis, invasion, and proliferation of PDAC cells were evaluated in vitro and in vivo. Hypoxia- and ENO1-induced gene expression was analyzed by transcriptomic sequencing.

RESULTS

The prognosis of PDAC with high ENO1 expression was poor (P < 0.05). High ENO1 expression was closely associated with histological differentiation and tumor invasion in 84 PDAC cases (P < 0.05). Hypoxia increased ENO1 expression in PDAC and promoted its migration and invasion. Apoptotic cells and the apoptosis marker caspase-3 in the CoCl₂-treated ENO1-sh group were significantly elevated (P < 0.05). Transcriptomic sequencing indicated that CoCl₂-induced PDAC cells initiated MAPK signaling. Under hypoxic conditions, PDAC cells upregulated ENO1 expression, thereby accelerating ERK phosphorylation and inhibiting apoptosis (P < 0.05). Consistent results were also observed in a PDAC-bearing mouse hindlimb ischemia model.

CONCLUSIONS

Hypoxia-induced ENO1 expression promotes ERK phosphorylation and inhibits apoptosis, thus leading to PDAC survival and invasion. These results suggest that ENO1 is a potential therapeutic target for PDAC.

Lenvatinib for effectively treating antiangiogenic drug-resistant nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) clinical trials show that antiangiogenic drugs (AADs) fail to achieve the expected efficacy, and combining AAD with chemoradiotherapy does not show superiority over chemoradiotherapy alone. Accumulating evidence suggests the intrinsic AAD resistance in NPC patients with poorly understood molecular mechanisms. Here, we describe NPC-specific FGF-2 expression-triggered, VEGF-independent angiogenesis as a mechanism of AAD resistance. Angiogenic factors screening between AAD-sensitive cancer type and AAD-resistant NPC showed high FGF-2 expression in NPC in both xenograft models and clinical samples. Mechanistically, the FGF-2-FGFR1-MYC axis drove endothelial cell survival and proliferation as an alternative to VEGF-VEGFR2-MYC signaling. Genetic knockdown of FGF-2 in NPC tumor cells reduced tumor angiogenesis, enhanced AAD sensitivity, and reduced pulmonary metastasis. Moreover, lenvatinib, an FDA recently approved multi-kinase inhibitor targeting both VEGFR2 and FGFR1, effectively inhibits the tumor vasculature, and exhibited robust anti-tumor effects in NPC-bearing nude mice and humanized mice compared with an agent equivalent to bevacizumab. These findings provide mechanistic insights on FGF-2 signaling in the modulation of VEGF pathway activation in the NPC microenvironment and propose an effective NPC-targeted therapy by using a clinically available drug.

Kallistatin prevents ovarian hyperstimulation syndrome by regulating vascular leakage

Angiogenesis and increased permeability are essential pathological basis for the development of ovarian hyperstimulation syndrome (OHSS). Kallistatin (KS) is an endogenous anti-inflammatory and anti-angiogenic factor that participates in a variety of diseases, but its role in OHSS remains unknown. In this study, treating a human ovarian granulosa-like tumour cell line KGN and human primary granulosa cells (PGCs) with human chorionic gonadotropin (hCG) reduced the expression of KS, but increased the expression of VEGF. Furthermore, we found that KS could attenuate the protein level of VEGF in both KGN cells and human PGCs. More interestingly, we observed that exogenous supplementation of KS significantly inhibited a series of signs of OHSS in mice, including weight gain, ovarian enlargement, increased vascular permeability and up-regulation of VEGF expression. In addition, KS was proved to be safe on mice ovulation, progression of normal pregnancy and fetus development. Collectively, these findings demonstrated that KS treatment prevented OHSS, at least partially, through down-regulating VEGF expression. For the first time, these results highlight the potential preventive value of KS in OHSS.

Targeting Stress Erythropoiesis Pathways in Cancer

Cancer-related anemia (CRA) is a common multifactorial disorder that adversely affects the quality of life and overall prognosis in patients with cancer. Safety concerns associated with the most common CRA treatment options, including intravenous iron therapy and erythropoietic-stimulating agents, have often resulted in no or suboptimal anemia management for many cancer patients. Chronic anemia creates a vital need to restore normal erythropoietic output and therefore activates the mechanisms of stress erythropoiesis (SE). A growing body of evidence demonstrates that bone morphogenetic protein 4 (BMP4) signaling, along with glucocorticoids, erythropoietin, stem cell factor, growth differentiation factor 15 (GDF15) and hypoxia-inducible factors, plays a pivotal role in SE. Nevertheless, a chronic state of SE may lead to ineffective erythropoiesis, characterized by the expansion of erythroid progenitor pool, that largely fails to differentiate and give rise to mature red blood cells, further aggravating CRA. In this review, we summarize the current state of knowledge on the emerging roles for stress erythroid progenitors and activated SE pathways in tumor progression, highlighting the urgent need to suppress ineffective erythropoiesis in cancer patients and develop an optimal treatment strategy as well as a personalized approach to CRA management.

Inflammatory cell-derived CXCL3 promotes pancreatic cancer metastasis through a novel myofibroblast-hijacked cancer escape mechanism

OBJECTIVE

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal malignancy and lacks effective treatment. We aimed to understand molecular mechanisms of the intertwined interactions between tumour stromal components in metastasis and to provide a new paradigm for PDAC therapy.

DESIGN

Two unselected cohorts of 154 and 20 patients with PDAC were subjected to correlation between interleukin (IL)-33 and CXCL3 levels and survivals. Unbiased expression profiling, and genetic and pharmacological gain-of-function and loss-of-function approaches were employed to identify molecular signalling in tumour-associated macrophages (TAMs) and myofibroblastic cancer-associated fibroblasts (myoCAFs). The role of the IL-33-ST2-CXCL3-CXCR2 axis in PDAC metastasis was evaluated in three clinically relevant mouse PDAC models.

RESULTS

IL-33 was specifically elevated in human PDACs and positively correlated with tumour inflammation in human patients with PDAC. CXCL3 was highly upregulated in IL-33-stimulated macrophages that were the primary source of CXCL3. CXCL3 was correlated with poor survival in human patients with PDAC. Mechanistically, activation of the IL-33-ST2-MYC pathway attributed to high CXCL3 production. The highest level of CXCL3 was found in PDAC relative to other cancer types and its receptor CXCR2 was almost exclusively expressed in CAFs. Activation of CXCR2 by CXCL3 induced a CAF-to-myoCAF transition and α-smooth muscle actin (α-SMA) was uniquely upregulated by the CXCL3-CXCR2 signalling. Type III collagen was identified as the CXCL3-CXCR2-targeted adhesive molecule responsible for myoCAF-driven PDAC metastasis.

CONCLUSIONS

Our work provides novel mechanistic insights into understanding PDAC metastasis by the TAM-CAF interaction and targeting each of these signalling components would provide an attractive and new paradigm for treating pancreatic cancer.

Improved indocyanine green retention after short-term lenvatinib withdrawal in three patients with hepatocellular carcinoma

Use of lenvatinib, which has a high response rate in advanced hepatocellular carcinoma, sometimes results in tumor shrinkage and resectability of previously unresectable liver cancers. In Asia, including Japan, liver reserve, one of the determinants of resectability, is mainly determined by the indocyanine green (ICG) retention rate. Three patients with advanced liver cancer treated at our institution had very poor ICG retention rates during treatment with lenvatinib. Lenvatinib may reduce blood flow in both cancerous and non-cancerous regions by inhibiting vascular endothelial growth factor. Therefore, accurate determination of liver function likely requires withdrawal of this treatment several days before ICG retention testing.

Angiotensin-converting enzyme inhibitors have adverse effects in anti-angiogenesis therapy for hepatocellular carcinoma

At present, anti-angiogenic drugs (AADs) are widely used in the systemic treatment of hepatocellular carcinoma (HCC) or other types of cancer, and have achieved good anti-cancer effect, whereas treatment-related proteinuria can affect the routine use of AADs, which in turn abates the overall efficacy. Currently, most clinicians prescribe angiotensin-converting enzyme inhibitors (ACEIs) to alleviate proteinuria according to diabetic nephropathy guidelines or expert recommendations. However, the efficacy of ACEIs in reducing AAD-related proteinuria and its effect on the anticancer effect of AADs is unknown. Our clinical data showed that some HCC patients experienced tumor progression by ACEIs administration for the treatment of proteinuria caused by AADs. Here, we confirmed that in different tumor-bearing mouse models, ACEIs did not delay the appearance of proteinuria or alleviate proteinuria caused by AADs but compromised the anticancer efficacy of AADs. This effect is unrelated to the change in the VEGF signaling pathway. Our data showed that the combination of ACEIs and AADs flared the production of kidney-derived erythropoietin (EPO). In turn, EPO compromises the anti-angiogenic effects of AADs and decreases antitumor activity. In conclusion, for the treatment of proteinuria caused by AADs, ACEIs have no efficacy while also promoting AADs resistance. This finding is of great significance to guide clinical standardized management of side effects of anti-angiogenic therapy for cancer patients.

Twist1 accelerates tumour vasculogenic mimicry by inhibiting Claudin15 expression in triple-negative breast cancer

The up-regulation of EMT regulator Twist1 has been implicated in vasculogenic mimicry (VM) formation in human triple-negative breast cancer (TNBC). Twist1 targets the Claudin15 promoter in hepatocellular carcinoma cells. Claudin family members are related with TNBC. However, the relationship between Claudin15 and VM formation is not clear. In this study, we first found that Claudin15 expression was frequently down-regulated in human TNBC, and Claudin15 down-regulation was significantly associated with VM and Twist1 nuclear expression. Claudin15 down-regulation correlated with shorter survival compared with high levels. Claudin15 silence significantly enhanced cell motility, invasiveness and VM formation in the non-TNBC MCF-7 cells. Conversely, an up-regulation of Claudin15 remarkably reduced TNBC MDA-MB-231 cell migration, invasion and VM formation. We also showed that down-regulation of Claudin15 was Twist1-dependent, and Twist1 repressed Claudin15 promoter activity. Furthermore, GeneChip analyses of mammary glands of Claudin15-deficient mice indicated that Claudin18 and Jun might be downstream factors of Twist1-Claudin15. Our results suggest that Twist1 induced VM through Claudin15 suppression in TNBC, and Twist1 inhibition of Claudin15 might involve Claudin18 and Jun expression.

Weekends-Off Lenvatinib for Unresectable Hepatocellular Carcinoma Improves Therapeutic Response and Tolerability toward Adverse Events

Background: Although lenvatinib has become the standard therapy for hepatocellular carcinoma (HCC), the high incidence rate of adverse events (AEs) is an issue. This study aimed to clarify the AEs of lenvatinib and the therapeutic impact of five days-on/two days-off administration (i.e., weekends-off strategy) for lenvatinib. Methods: We retrospectively assessed the therapeutic effects and AEs of 135 patients treated with lenvatinib, and the improvement of tolerability and therapeutic efficacy of 30 patients treated with the weekends-off strategy. We also evaluated lenvatinib-induced vascular changes in tumors and healthy organs using a mouse hepatoma model. Results: The incidence rates of any grade and grade ≥ 3 AEs were 82.1% and 49.6%. Fatigue was the most important AE since it resulted in dose reduction and discontinuation. Of the 30 patients who received weekends-off lenvatinib, 66.7% tolerated the AEs. Although 80.8% of the patients showed progression after dose reduction, the therapeutic response improved in 61.5% of the patients by weekends-off lenvatinib. Notably, weekends-off administration significantly prolonged the administration period and survival (p < 0.001 and p < 0.05). The mouse hepatoma model showed that weekends-off administration contributed to recovery of vascularity in the organs. Conclusion: Weekends-off administration of lenvatinib was useful to recover the therapeutic response and tolerability toward AEs.

M2 macrophages mediate sorafenib resistance by secreting HGF in a feed-forward manner in hepatocellular carcinoma

Background

Sorafenib is the only approved first line systemic therapy for advanced hepatocellular carcinoma (HCC) in the last decade. Tumour resistance to sorafenib has been of major obstacles to improve HCC patient survival.

Methods

We polarised THP-1 cells to M1 and M2 macrophages, performed various in vitro assays and developed sorafenib-resistant xenograft models to investigate the role of tumour-associated macrophages (TAM)-secreted molecules in HCC resistance to the targeted therapy.

Results

We demonstrated M2, but not M1, macrophages not only promote proliferation, colony formation and migration of hepatoma cells but also significantly confer tumour resistance to sorafenib via sustaining tumour growth and metastasis by secreting hepatocyte growth factor (HGF). HGF activates HGF/c-Met, ERK1/2/MAPK and PI3K/AKT pathways in tumour cells. Tumour-associated M2 macrophages were accumulated in sorafenib-resistance tumours more than in sorafenib-sensitive tumours in vivo and produced abundant HGF. HGF chemoattracts more macrophages migrated from surrounding area, regulates the distribution of M2 macrophages and increases hepatoma resistance to sorafenib in a feed-forward manner.

Conclusions

Our results provide new insights into the mechanisms of sorafenib resistance in HCC and rationale for developing new trials by combining sorafenib with a potent HGF inhibitor such as cabozantinib to improve the first line systemic therapeutic efficacy.

VEGF expands erythropoiesis via hypoxia-independent induction of erythropoietin in noncanonical perivascular stromal cells

Greenwald et al. show that VEGF can function as a potent hypoxia-independent inducer of erythropoietin in a population of VSMC-like perivascular stromal cells in a PDGFRβ-dependent manner, thereby expanding erythropoiesis by recruitment of additional cell types to the erythropoietin-producing cell pool.

Insufficient erythropoiesis due to increased demand is usually met by hypoxia-driven up-regulation of erythropoietin (Epo). Here, we uncovered vascular endothelial growth factor (VEGF) as a novel inducer of Epo capable of increasing circulating Epo under normoxic, nonanemic conditions in a previously unrecognized reservoir of Epo-producing cells (EPCs), leading to expansion of the erythroid progenitor pool and robust splenic erythropoiesis. Epo induction by VEGF occurs in kidney, liver, and spleen in a population of Gli1⁺SMA⁺PDGFRβ⁺ cells, a signature shared with vascular smooth muscle cells (VSMCs) derived from mesenchymal stem cell–like progenitors. Surprisingly, inhibition of PDGFRβ signaling, but not VEGF signaling, abrogated VEGF-induced Epo synthesis. We thus introduce VEGF as a new player in Epo induction and perivascular Gli1⁺SMA⁺PDGFRβ⁺ cells as a previously unrecognized EPC reservoir that could be harnessed for augmenting Epo synthesis in circumstances such as chronic kidney disease where production by canonical EPCs is compromised.