Antibody therapy in renal cell carcinoma

The treatment of metastasized renal cell carcinoma (RCC) still represents a formidable challenge, despite the development of small molecule, tyrosine kinase inhibitors (TKI) that have made a major impact on the disease. Although the percentage of patients achieving a partial response or stabilization of disease has been impressive, these effects are mostly non-durable. Additionally, drug-related side effects can be quite severe. Alternative treatment modalities might be monoclonal antibodies (mAbs). mAbs against RCC-associated antigens have been developed and have shown promise. Additionally, current efforts focus on Bevacizumab that recognizes vascular endothelial growth factor (VEGF). VEGF overexpression in RCC provides the opportunity to inhibit this proangiogenic pathway. Also with Bevacizumab, promising results have been obtained, particularly in combination with other treatment modalities. It is likely that mAbs, either as single agents or in combination with other agents, may become useful additions to the armamentarium to diagnose and treat RCC.     

The role of vascular endothelial growth factor (VEGF) in renal pathophysiology

Vascular endothelial growth factor (VEGF) is an endothelial-specific growth factor that promotes endothelial cell proliferation, differentiation and survival, mediates endothelium-dependent vasodilatation, induces microvascular hyperpermeability and participates in interstitial matrix remodeling. In the kidney, VEGF expression is most prominent in glomerular podocytes and in tubular epithelial cells, while VEGF receptors are mainly found on preglomerular, glomerular, and peritubular endothelial cells. The role of VEGF in normal renal physiology is essentially unknown. The absence of prominent effects of VEGF blockade in normal experimental animals suggests a limited function during homeostasis, although a role in the formation and maintenance of glomerular capillary endothelial fenestrations has been suggested. VEGF and its receptors are up-regulated in experimental animals and humans with type 1 and type 2 diabetes. Inhibition of VEGF has beneficial effects on diabetes-induced functional and structural alterations, suggesting a deleterious role for VEGF in the pathophysiology of diabetic nephropathy. VEGF is required for glomerular and tubular hypertrophy and proliferation in response to nephron reduction, and loss of VEGF is associated with the development of glomerulosclerosis and tubulointerstitial fibrosis in the remnant kidney. No firm conclusions on the role of VEGF in minimal change or membranous glomerulonephritis can be drawn. VEGF may be an essential mediator of glomerular recovery in proliferative glomerulonephritis. Glomerular and tubulointerstitial repair in thrombotic microangiopathy and cyclosporin nephrotoxicity may also be VEGF-dependent. In conclusion, VEGF is required for growth and proliferation of glomerular and peritubular endothelial cells. While deleterious in some, it may contribute to recovery in other forms of renal diseases.     

肾细胞癌中血管内皮生长因子的表达

目的 探讨肾癌组织中血管内皮生长因子的表达及其与肾癌生物学行为的关系。方法 应用单克隆鼠抗-VEGF抗体通过免疫组化SP法研究肾癌中血管内皮生长因子的表达。结果 60例肾癌组织中35例(58.3％)血管内皮生长因子阳性。血表达与组织学分级(P<0.05)和TNM分期(P<0.05)均明显相关。 结论 血管内皮生长因子表达对肾癌生物学行为有重要影响,设法抑制血管内皮生长因子有望成为肾癌治疗的另一有效方法。     

Tumour vascular endothelial growth factor (VEGF) mRNA in relation to serum VEGF protein levels and tumour progression in human renal cell carcinoma

Angiogenesis is gaining interest because of its importance in tumour growth and metastasis. Renal cell carcinoma (RCC) is known to be a well-vascularized tumour. The aim of this study was to evaluate the expression of VEGF mRNA and receptor flt-1 mRNA (VEGF R1) in a clinical material of RCCs compared with clinicopathological variables and serum VEGF levels. Total RNA was extracted from snap-frozen tumour tissue obtained from 61 patients. Expression of mRNA for VEGF₁₂₁, VEGF₁₆₅ and flt-1 were analysed using quantitative RT-PCR. Relative VEGF mRNA levels, corrected for corresponding cyclophilin value, were related to stage, grade, RCC type and survival time. Serum VEGF₁₆₅ protein was analysed using a quantitative ELISA. Papillary RCC had significantly lower VEGF₁₂₁ and flt-1 mRNA levels compared with conventional RCC (p=0.001). VEGF₁₂₁ mRNA levels were significantly lower in locally advanced tumours in relation to tumours limited to the kidney and those with metastatic disease (p=0.047 and p=0.036). This statistical difference disappeared when only conventional RCCs were evaluated. No association was found between VEGF mRNA levels and nuclear grade. Patients with lower VEGF₁₂₁ mRNA levels had significantly longer survival time compared with those with higher levels (when adjusted to stage, p=0.0097, log rank test). There was an inverse relation between VEGF₁₆₅ mRNA and serum VEGF₁₆₅ levels. The trend to lower VEGF₁₂₁ mRNA levels in locally advanced RCC indicate that angiogenic activity and degradation might be up-regulated in tumours with a high ability to invade. The association with tumour progression shows that VEGF is a promising angiogenic factor especially important in conventional RCCs. VEGF expression might possibly be of help to identify RCCs susceptible for anti-angiogenic therapies.     

血管内皮生长因子与肾间质纤维化

肾间质纤维化涉及多方面的因素,其中管周毛细血管网的丢失参与了肾间质纤维化的进展。血管内皮生长因子的异常表达与管周毛细血管网丢失有着较大的关系。本文综述了血管内皮生长因子与肾间质纤维化发展的关系以及可能的机制。     

血管内皮细胞生长因子mRNA在肾细胞癌中的表达

用逆转录聚合酶链反应（ＲＴＰＣＲ）方法检测２０例肾细胞癌组织和癌周组织血管内皮细胞生长因子（ＶＥＧＦ）ｍＲＮＡ的表达，有１８例癌组织表达ＶＥＧＦｍＲＮＡ，表达率为９０％；２例无表达。癌周组织仅有３例表达ＶＥＧＦｍＲＮＡ，表达率为１５％，两组间有显著性差异（Ｐ＜０．０１）。结果表明，ＶＥＧＦ在肾细胞癌的生长和进展过程中起重要作用，通过诱导血管内皮细胞通透性和内皮细胞的增生，促进肿瘤生长。以ＶＥＧＦ作为靶分子的基因治疗将提高防治肾癌进展和转移的水平。     

Serum levels of vascular endothelial growth factor (VEGF) and endostatin in renal cell carcinoma patients compared to a control group

OBJECTIVES: Renal cell carcinoma (RCC) is a vascularised neoplasm. The importance of the angiogenic process in its growth and metastatic spreading is widely recognised. We assessed serum levels of endogenous endostatin and vascular endothelial growth factor (VEGF) in RCC patients and healthy volunteers, and evaluated the factors' prognostic role for patients' survival, distinguishing histologic subtypes with respect to correlation with tumour stage, grade, and size. METHODS: We considered 146 consecutive patients with RCC and 110 healthy volunteers. Serum samples from all subjects were analysed for endostatin and VEGF by using competitive enzyme immunoassays. RCC samples were compared with serum from the control group and with clinicopathologic factors and clinical outcome. RESULTS: Mean age was 63 years (range: 37-85 years) in RCC patients and 62 years (range: 23-88 years) in the control group. VEGF levels (median: 3.6 ng/ml+/-6.97; range: 0-48.4 ng/mL) were significantly higher in RCC patients, compared with controls (p=0.001). Endostatin levels did not differ significantly between the two groups (p=0.9) without correlation between endostatin and VEGF levels (p=0.09). No significant difference was found in the endostatin levels among the histologic subtypes (p=0.973) and VEGF (p=0.232). The median follow-up was 27 months (range: 1-57 months). CONCLUSIONS: Serum VEGF levels are elevated in RCC patients, compared with controls, and do not correlate significantly with circulating endostatin levels. No difference in preoperative serum VEGF and endostatin levels among the different histologic subtypes was found. In multivariate analysis VEGF and endostatin failed to be prognostic; only tumour stage and grade remained independent predictors of survival.     

Expression of vascular endothelial growth factor protein in human renal cell carcinoma

OBJECTIVE: To evaluate the effect of vascular endothelial growth factor (VEGF, one of the most important angiogenetic factors) in renal cell carcinoma (RCC) by analysing many RCCs for the expression of immunohistochemical (IHC) VEGF-staining related to clinicopathological findings and survival. PATIENTS AND METHODS: VEGF immunostaining was examined with the tissue microarray (TMA) method on tumour samples from 229 patients and validated in 71 by ordinary tissue sections (TS). IHC VEGF expression was quantified by estimating the volume density and staining intensity on a three-grade scale. RESULTS: In most RCCs there was VEGF staining in the cell cytoplasm and membrane. In cell membranes the VEGF expression declined with storage time. IHC VEGF expression analysed by TMA and TS gave corresponding results. There was no difference in VEGF expression among conventional, papillary and chromophobe RCCs. There were significant correlations between VEGF expression and tumour size and stage. In univariate analysis VEGF expression correlated with survival, especially in conventional RCCs; this prognostic information was lost in multivariate analysis. The VEGF staining intensity correlated only with VEGF expression but not with any clinicopathological factors. CONCLUSIONS: VEGF protein was present in most RCC cells. There was no difference in VEGF expression among the different RCC types. The correlation between VEGF expression and tumour stage and with prognosis indicates the significance of VEGF within tumour growth and progression in RCC.     

靶向血管内皮细胞治疗肝癌的实验研究

目的 运用抗肝癌区血管内皮细胞的单克隆抗体进行抑癌实验。方法 通过建立裸小鼠人肝癌动物模型来进行,抑瘤实验。结果 抗肝癌区血管内皮细胞的单克隆抗体在肝癌动物模型的抑瘤裕有明显的抑瘤作用。结论 抗体在动物实验中明显的抑瘤作用,表明通过应用这种抗体可对肝癌进行以血管为靶向的生物治疗,从而为肝癌的治疗提供一种新的治疗方法。     

Current challenges and unmet needs in treating patients with human epidermal growth factor receptor 2-positive advanced breast cancer

Human epidermal growth factor receptor 2 oncogene (HER2-positive) overexpression/amplification occurs in less than 20% of breast cancers and has traditionally been associated with poor prognosis. Development of therapies that target HER2 has significantly improved outcomes for patients with HER2-positive advanced breast cancer (ABC). Currently available HER2-targeted agents include the monoclonal antibodies trastuzumab, pertuzumab, and margetuximab, the small-molecule inhibitors lapatinib, tucatinib, neratinib, and pyrotinib, as well as the antibody-drug conjugates trastuzumab emtansine and trastuzumab deruxtecan. Optimal sequencing of these agents in the continuum of the disease is critical to maximize treatment outcomes. The large body of clinical evidence generated over the past 2 decades aids clinicians in treatment decision-making. However, patients with HER2-positive ABC and specific disease characteristics and/or comorbidities, such as leptomeningeal disease, brain metastases, or cardiac dysfunction, are generally excluded from large randomized clinical trials, and elderly or frail patients are often underrepresented. In addition, there is great inequality in the accessibility of approved drugs across countries. This article addresses various challenging clinical situations when treating patients with HER2-positive ABC. The objective is to provide guidance to clinicians on how and when HER2-targeted therapies and additional treatments can be best implemented in routine clinical practice, on the basis of existing clinical evidence and expert opinion where needed.     

肾细胞癌VEGF表达和MVD检测的临床意义

目的 探讨肾细胞癌（RCC）组织中血管内皮细胞生长因子（VEGF）的表达与肿瘤间质微血管密度（MVD）检测的临床意义。方法 采用免疫组化方法对65例肾细胞癌（RCC）及10例正常肾组织进行VEGF单克隆抗体及CD34单克隆抗体染色，观察RCC的VEGF表达与MVD之间的相关性。结果 VEGF的表达与肿瘤间质微血管密度之间存在正相关性，二者均与RCC的病理分级、临床分期及远处转移显著相关（P〈0.05，P〈O．001）。结论 VEGF与MVD可客观准确反映RCC的生物学行为，上述二项指标可作为评估RCC恶性程度、转移及预后的重要指标。     

Distribution of vascular endothelial growth factor (VEGF) in prostate disease

Vascular endothelial growth factor (VEGF) is a heparin-binding polypeptide growth factor. It is a potent mitogen for endothelial cells. Immunohistochemical localisation of VEGF was performed on 25 moderate to poorly differentiated stage T4 M+ prostate cancer specimens and 30 benign prostatic hyperplasia (BPH) specimens. A positive result was indicated by area staining >25% and +2 or +3 staining intensity. Positive epithelial staining was observed in 50% of BPH specimens and 56% of cancer specimens, while positive stromal staining was observed in 73% of BPH specimens and 30% of cancer specimens. This may reflect an active role for stromal VEGF in the pathological process of BPH.     

Autocrine and paracrine functions of vascular endothelial growth factor (VEGF) in renal tubular epithelial cells

BACKGROUND: VEGF secreted by organ parenchymal cells controls vascularization by recruiting endothelial cells and supporting their proliferation. In the developing kidney VEGF-expressing epithelial cells also express VEGF receptors. We showed that VEGF stimulates tubulogenesis in addition to promoting vascularization in metanephric explants. Since explants are grown in serum-free media and are not perfused, we hypothesized that VEGF secreted by renal epithelia may induce their proliferation in an autocrine manner and chemoattract endothelial cells. METHODS: To test these hypotheses, we analyzed VEGF-mediated responses in vitro using several renal epithelial cell lines [immortalized rat proximal tubular cells (IRPT), transformed mouse proximal tubular cells (tsMPT), and normal rat kidney cells (NRK-52E)] expressing VEGF receptors (VEGFR). RESULTS: We demonstrated that VEGFR-2 phosphorylates upon human recombinant VEGF (rhVEGF) exposure, indicating that VEGFR-2 is the signaling receptor. All three cell lines secreted VEGF into the media as indicated by enzyme-linked immunosorbent assay (ELISA) and Western blotting. We showed that these tubular epithelial cells chemoattract endothelial cells when cocultured in vitro and that the chemoattraction is abolished by anti-VEGF neutralizing antibody. rhVEGF (10 ng/mL) induced a mitogenic effect similar to 10% fetal bovine serum (FBS) as assessed by H(3)-thymidine incorporation and elicited 30% decrease in apoptosis as determined by annexin V-fluorescein isothiocyanate (FITC) staining. CONCLUSION: These in vitro studies indicate that (1) tubular epithelial cells chemoattract endothelial cells in a paracrine fashion by secreting VEGF, and (2) VEGF stimulates proliferation and promotes survival of renal epithelial cells in an autocrine manner via VEGFR-2. Taken together, our results suggest that VEGF supports the growth of renal epithelia in addition to mediating kidney vascularization.     

血管内皮生长因子在肾细胞癌中的表达及意义

研究肾细胞癌血管内皮生长因子（ＶＥＧＦ）的表达及其与肿瘤转移、分期、病理类型及预后的关系。采用抗ＶＥＧＦ的多克隆抗体免疫组织化学技术染色（ＬｓＡＢ法）研究６１例肾癌组织切片。结果显示：４５９％（２８／６１）的肾癌ＶＥＧＦ表达阳性，淋巴结和（或）血行转移的ＶＥＧＦ表达率（７７８％）明显高于非转移者（３２６％，Ｐ＜００１）；阳性表达者五年生存率（２９１％）明显低于阴性表达者（８４６％，Ｐ＜００１）；Ⅰ、Ⅱ期阳性表达低于Ⅲ、Ⅳ期（Ｐ＜００５）；但与性别、年龄及肿瘤的病理类型无关。ＶＥＧＦ除在癌细胞胞浆和胞膜表达外，尚表达于肿瘤基质血管和邻近肿瘤的正常肾小管胞浆、肾小球和血管内皮及血管平滑肌胞膜。认为ＶＥＧＦ除由肿瘤细胞合成外，可能尚表达于邻近肿瘤的正常肾小管胞浆，ＶＥＧＦ表达有助于肾癌预后判断及指导治疗，ＶＥＧＦ可能是肿瘤血管的良好标记物，设法抑制ＶＥＧＦ可望成为肾癌治疗的有效方法。     

血管内皮细胞生长因子(VEGF)基因转染骨髓间充质干细胞的表达

目的检测兔骨髓间充质干细胞(BMSc)经血管内皮细胞生长因子(VEGF165)基因转染后外源基因的表达，为进一步利用经基因转染的BMSc构建血管化组织工程骨组织打下基础。方法构建VEGF真核细胞表达载体，利用脂质体介导转染兔BMSc，使用原位杂交、免疫组织化学的方法检测VEGF165在BMSc中的表达。结果成功构建VEGF真核细胞表达载体，原位杂交、免疫组化方法显示经基因转染的BMSc中有阳性棕黄色颗粒出现，而未转染组呈现阴性结果。结论采用基因转移技术可以将VEGF转染至．BMSc中，并有外源性基因和蛋白的表达。     

抗肝肠钙粘连蛋白单克隆抗体对肝癌细胞生物学行为的影响

目的 观察抗肝肠钙粘连蛋白(CDH17)单克隆抗体Lic5对肝癌细胞生物学行为的影响.方法 Western blot和实时定量聚合酶链反应(PCR)检测细胞株MHCC97H、MHCC97L、PLC/PRF/5及MIHA中CDH17的表达.噻唑蓝(MTT)比色法、细胞划痕法、Transwell法及平板克隆法检测Lic5对肝癌细胞生物学行为的影响.结果 CDH17仅在细胞株MHCC97H、MHCC97L中表达,Lic5可结合肝癌细胞表面的CDH17,并抑制CDH17表达.Lic5 50mg/L组、100mg/L组、小鼠IgG组4 d细胞增殖抑制率在MHCC97H为26.1%、43.6%、6.4%,MHCC97L为26.0%、40.7%、7.7%;Lic5100mg/L组、小鼠IgG组、磷酸盐缓冲液(PBS)组48h细胞迁移抑制率在MHCC97H为36.7%、8.4%、5.6%,MHCC97L为42.3%、10.2%、7.4%(P＜0.05);穿膜细胞数在MHCC97H为(39.20±9.56)、(106.50±7.56)、(96.60±13.02)个,MHCC97L为(26.00±8.61)、(86.00±10.26)、(90.40±12.04)(P＜0.05);克隆形成数在MHCC97H为(59.30±11.68)、(141.70±19.40)、(150.30±14.64),MHCC97L为(57.20±10.21)、(132.50±9.07)、(121.70±11.93)(P＜0.01).Lic5对PLC/PRF/5及MIHA细胞的生物学行为无明显影响.结论 单克隆抗体Lic5能够下调肝癌细胞CDH17表达,抑制肝癌细胞的增殖、迁移、侵袭和克隆形成能力.

Abstract：

Objective To investigate the effect of monoclonal antibody against liver-intestine cadherin (CDH17) on the cell proliferation, migration, invasion and colony formation of hepatocellular carcinoma cell lines. Methods Hepatocellular carcinoma cell lines MHCC97H, MHCC97L, PLC/PRF/5 and MIHA were examined for CDH17 expression by Western blotting and quantitative real-time polymerase chain reaction (PGR). The combination capacity between bepatocellular carcinoma cell lines and monoclonal antibody Lic5 was detected by the way of immunofluorescence staining. The cell lines were treated with Lic5, PBS and mouse IgG respectively. Methyl thiazol tetrazolium (MTT) assay, wound healing assay, Transwell invasion assay and colony formation assay were used to study the changes in cell proliferation, migration, invasion and colony formation of hepatocellular carcinoma cell lines. Results High expression level of CDH17 was detected in MHCC97H and MHCC97L cell lines. CDH17 protein level was down-regulated but there was no significant effect on CDH17 mRNA after treatment with Lie5 in MHCC97H and MHCC97L. Cellular growth rate of MHCC97H in Lic5 (50 mg/L), Lic5 ( 100 mg/L) and mouse IgG groups was decreased by 26. 1%, 43.6% and 6. 4%, and by 26. 0%, 40. 7% and 7. 7% in MHCC97L on the 4th day respectively (P ＜0. 05 ). The inhibition rate of cell migration at 48 h was 36. 7%, 8. 4% and 5.6% in Lic5 ( 100 mg/L), mouse IgG and PBS groups in MHCC97H, and 42. 3%, 10. 2% and 7. 4% in MHCC97L respectively ( P ＜ 0. 05 ). The number of invasion cells was ( 39. 20 t 9. 56),(106.50±7.56) and (96.60±13.02) in MHCC97H, and (26.00±8.61), (86.00±10.26) and (90.40±12.04) in MHCC97L in Lic5 (50 mg/L), Lic5 (100 mg/L) and mouse IgG groups, respectively (P ＜ 0. 05 ). The number of colony formation was ( 59. 30 ± 11.68 ), ( 141.70 ± 19. 40 ) and (150.30 ±14.64) in MHCC97H, and (57.20 ± 10.21), (132.50 ±9.07) and (121.70 ±11.93) in MHCC97L in Lie5 (50 mg/L), Lic5 (100 mg/L) and mouse IgG groups, respectively (P＜ 0. 01 ).There was no significant difference between Lic5 treatment groups and controls in PLC/PRF/5 and MIHA cell lines. Conclusion The anti-CDH17 monoclonal antibody Lic5 can down-regulate CDH17 expression and inhibit the cell proliferation, migration, invasion and colony formation in hepatocellular carcinoma cell lines.