Renal Cancer Metastasis Research Articles

IFI35 Promotes Renal Cancer Progression by Inhibiting pSTAT1/pSTAT6-Dependent Autophagy.

Simple SummaryInterferon-induced protein 35 (IFI35) plays an important role in virus-related immune inflammatory responses. However, the biological significance and function of IFI35 in cancer is still not well understood. Our goal is to explore whether IFI35 could be used as tumor marker or a therapeutic target for renal cell cancer (RCC). Our results showed that IFI35 expression was significantly increased in 200 RCC specimens, and its expression was negatively associated with poor overall or disease-specific 5-year patients’ survival. Next, we explored the mechanism and function of IFI35 in RCC. The results demonstrated that knockdown of IFI35 could inhibit the proliferation and invasion of renal cancer cells by enhancing the STAT1/STAT6 phosphorylation (pSTAT1/pSTAT6)-dependent autophagy. Likewise, the knockdown of IFI35 also suppressed the tumor growth or lung metastasis of renal cancer by enhancing the induction of autophagy. This study aims to provide a theoretical basis for IFI35 as a potential diagnosis and therapeutic target for RCC or other cancers with high levels of IFI35.Interferon-induced protein 35 (IFI35), is currently acknowledged to govern the virus-related immune inflammatory responses. However, the biological significance and function of IFI35 in renal cell cancer (RCC) is still not well understood. Here, IFI35 expression and function were investigated in RCC tissues, renal cancer cells, and animal models. The results showed that IFI35 expression was significantly increased in 200 specimens of RCC patients. We found that higher IFI35 levels were significantly correlated with poor RCC prognosis. In human cell lines, the knockdown of IFI35 suppressed the malignant behavior of renal cancer cells. Similarly, the IFI35 knockdown resulted in significant inhibition of tumor progression in the subcutaneous or lung metastasis mouse model. Furthermore, the knockdown of IFI35 promoted the induction of autophagy by enhancing the autophagy-related gene expression (LC3-II, Beclin-1, and ATG-5). Additionally, blockade of STAT1/STAT6 phosphorylation (pSTAT1/pSTAT6) abrogated the induced autophagy by IFI35 knockdown in renal cancer cells. The autophagy inhibitor 3-MA also abolished the prevention of tumor growth by deleting IFI35 in renal cancer models. The above results suggest that the knockdown of IFI35 suppressed tumor progression of renal cancer by pSTAT1/pSTAT6-dependent autophagy. Our research revealed that IFI35 may serve as a potential diagnosis and therapeutic target for RCC.

Similarities and differences in the process of metastasis and differentiation of renal cancer on gene expression

Background. Metastasing and degree of differentiation refer to the main clinical characteristics of malignant tumors. Both listed features need an in-depth study that can lead to an understanding of the mechanisms for the occurrence of certain state of cancer cells.Objective. Studying the processes of metastasis and differentiation of the clear cell renal cell carcinoma (ccRCC) on gene expression.Materials and methods. The levels of expression of ten genes in 65 paired samples were studied (ccRCC tumor tissue and the normal kidney tissue) by the real-time polymerase chain reaction.Results. It is shown that the expression of CA9, NDUFA4L2, VWF, IGFBP3, BHLHE41, ANGPTL4 and EGLN3 genes is associated both with the degree of differentiation of the ccRCC and with the metastasis of this tumor. C1QA expression is connected only with metastasis, but does not participate in the process of differentiation of tumor cells. An ambiguous situation with FN1 and CSF1R gene expression is not essential for ccRCC metastasis processes, but may have a certain value for differentiation of cells of this tumor. Low-differentiated tumors have about five times an increased metastasis frequency during the year relative to highly differentiated tumors (odds ratio 4.94). A low correlation of gene expression in tumors with a low degree of differentiation is revealed, as opposed to their high co-expression during tumor progression by TNM classifications.Conclusion. A significant part of genes substantial for the development of ccRCC is associated with both metastasis and the degree of differentiation of the ccRCC, which is due to the similarity of functional changes that stimulate both of these processes. For low-differentiated tumors the number of genes with correlated expression is less than in high-differentiated tumors. This may be due to disorganization of gene expression.

Metastatic Immune-Related Genes for Affecting Prognosis and Immune Response in Renal Clear Cell Carcinoma.

Background: In renal clear cell carcinoma, a common cancer of the urinary system, 25–30% patients are metastatic at initial diagnosis and 20–30% patients have a tendency of recurrence and metastasis after local surgery. With the rapid development of tumor immunology, immune agents have brought new directions to tumor therapy. However, no relevant studies have explored the role of immune-related genes in kidney cancer metastasis. Methods: Co-expressed metastatic immune-related differentially expressed genes (mIR-DEGs) were screened by GSE12606, GSE47352, and immunorelated genes. Then, differential expression analysis, prognostic analysis, and univariate and multivariate Cox regression analysis in KIRC were performed to determine independent prognostic factors associated, and the risk prognostic model was established. The correlation of hub mIR-DEGs with clinicopathological factors, immune invasion, and immune checkpoints was analyzed, and the expression of hub mIR-DEGs and their effect on tumor were re-evaluated by OCLR scores in KIRC. Results: By comprehensive bioassay, we found that FGF17, PRKCG, SSTR1, and SCTR were mIR-DEGs with independent prognostic values, which were significantly associated with clinicopathological factors and immune checkpoint–related genes. The risk prognostics model built on this basis had good predictive potential. In addition, targeted small molecule drugs, including calmidazolium and sulfasalazine, were predicted for mIR-DEGs. Further experimental results were consistent with the bioinformatics analysis. Conclusion: This study preliminarily confirmed that FGF17, PRKCG, SSTR1, and SCTR were targeted genes affecting renal cancer metastasis and related immune responses and can be used as potential therapeutic targets and prognostic biomarkers for renal cancer. Preliminary validation found that PRKCG and SSTR1 were consistent with predictions.

Glycocalyx mechanotransduction mechanisms are involved in renal cancer metastasis

Mammalian cells, including cancer cells, are covered by a surface layer containing cell bound proteoglycans, glycoproteins, associated glycosaminoglycans and bound proteins that is commonly referred to as the glycocalyx. Solid tumors also have a dynamic fluid microenvironment with elevated interstitial flow. In the present work we further investigate the hypothesis that interstitial flow is sensed by the tumor glycocalyx leading to activation of cell motility and metastasis. Using a highly metastatic renal carcinoma cell line (SN12L1) and its low metastatic counterpart (SN12C) we demonstrate in vitro that the small molecule Suberoylanilide Hydroxamic Acid (SAHA) inhibits the heparan sulfate synthesis enzyme N-deacetylase-N-sulfotransferase-1, reduces heparan sulfate in the glycocalyx and suppresses SN12L1 motility in response to interstitial flow. SN12L1 cells implanted in the kidney capsule of SCID mice formed large primary tumors and metastasized to distant organs, but when treated with SAHA metastases were not detected. In another set of experiments, the role of hyaluronic acid was investigated. Hyaluronan synthase 1, a critical enzyme in the synthetic pathway for hyaluronic acid, was knocked down in SN12L1 cells and in vitro experiments revealed inhibition of interstitial flow induced migration. Subsequently these cells were implanted in mouse kidneys and no distant metastases were detected. These findings suggest new therapeutic approaches to the treatment of kidney carcinoma metastasis.

Study on Circulating Tumor Cells and Various Clinical Features and Blood-Related Indexes in Patients with Renal Cancer

Objective: To investigate the value of CTC clinical features and blood-related test indicators in renal cancer patients by detecting the number of circulating tumor cells (CTC) in patients with renal cancer. Methods: To analyze 59 patients with renal cell carcinoma (RCC) admitted to the Department of Urology, Affiliated Hospital of Chengde Medical College from May 2018 to October 2019. According to the CTC count (5 pcs/3.5 ml), they were divided into CTC positive group and CTC negative group. The age, gender, tumor location, tumor size, hematuria, CEC (circulating endothelial cells), CTC Cluster (aggregate), gene mutation, platelet (PLT), albumin (ALB), hemoglobin (HB), alkaline phosphatase (AKP), lactate dehydrogenase (LDH) were compared between the two groups of patients and the correlation of the number of CTCs. Results: There were significant differences in tumor size, CEC, and gene mutations between the two groups (P Conclusion: The number of CTC in RCC patients is correlated with some clinical features (tumor size, CEC, gene mutation) and some related test indicators (HB, PLT, LDH), and can be combined with the above related indicators to predict the occurrence, metastasis and prognosis of renal cancer.

Identification of a Novel Stem Cell Subtype for Clear Cell Renal Cell Carcinoma Based on Stem Cell Gene Profiling.

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cancer and is characterized by high rates of metastasis. Cancer stem cell is a vital cause of renal cancer metastasis and recurrence. However, little is known regarding the change and the roles of stem cells during the development of renal cancer. To clarify this problem, we developed a novel stem cell clustering strategy. Based on The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC) genomic datasets, we used 19 stem cell gene sets to classify each dataset. A machine learning method was used to perform the classification. We classified ccRCC into three subtypes—stem cell activated (SC-A), stem cell dormant (SC-D), and stem cell excluded (SC-E)—based on the expressions of stem cell-related genes. Compared with the other subtypes, C2(SC-A) had the highest degree of cancer stem cell concentration, the highest level of immune cell infiltration, a distinct mutation landscape, and the worst prognosis. Moreover, drug sensitivity analysis revealed that subgroup C2(SC-A) had the highest sensitivity to immunotherapy CTLA-4 blockade and the vascular endothelial growth factor receptor (VEGFR) inhibitor sunitinib. The identification of ccRCC subtypes based on cancer stem cell gene sets demonstrated the heterogeneity of ccRCC and provided a new strategy for its treatment.

Hsa_circ_0065217 promotes growth and metastasis of renal cancer through regulating the miR-214-3p-ALPK2 axis

ABSTRACT Circular RNA (circRNA) deregulation impacts on normal cell physiology leading to malignant phenotypic changes. Here, we determined the function of the circRNA, hsa_circ_0065217 in malignant renal cell carcinoma (RCC). Hsa_circ_0065217 was abundantly expressed in RCC tissue and cell lines, and its expression linked to advanced TNM stages, large tumor sizes, and lymph-node metastasis. Hsa_circ_0065217 silencing reduced in vitro RCC cell-line growth and aggressiveness. Mechanistically, hsa_circ_0065217 promoted alpha protein kinase 2 (ALPK2) expression via its competing endogenous RNA (ceRNA) activity toward miR-214-3p. Moreover, ALPK2 overexpression reversed hsa_circ_0065217 knockdown effects on RCC cell-line malignancy. Thus, hsa_circ_0065217/miR-214-3p/ALPK2 signaling putatively promotes RCC tumorigenesis and is a putative RCC treatment target.

TKI-Resistant Renal Cancer Secretes Low-Level Exosomal miR-549a to Induce Vascular Permeability and Angiogenesis to Promote Tumor Metastasis.

Tyrosine kinase inhibitors (TKI)-resistant renal cancer is highly susceptible to metastasis, and enhanced vascular permeability promotes the process of metastasis. To evaluate the effect of cancer-derived exosomes on vascular endothelial cells and clarify the mechanism of metastasis in TKI-resistant renal cancer, we studied the crosstalk between clear cell renal cell carcinoma (ccRCC) cells and human umbilical vein endothelial cells (HUVECs). Exosomes from ccRCC cells enhanced the expression of vascular permeability-related proteins. Compared with sensitive strains, exosomes from resistant strains significantly enhanced vascular endothelial permeability, induced tumor angiogenesis and enhanced tumor lung metastasis in nude mice. The expression of miR-549a is lower in TKI-resistant cells and exosomes, which enhanced the expression of HIF1α in endothelial cells. In addition, TKI-resistant RCC cells reduced nuclear output of pre-miR-549a via the VEGFR2-ERK-XPO5 pathway, and reduced enrichment of mature miR-549a in cytoplasm, which in turn promoted HIF1α expression in RCC, leading to increased VEGF secretion and further activated VEGFR2 to form a feedback effect. miR-549a played an important role in the metastasis of renal cancer and might serve as a blood biomarker for ccRCC metastasis and even had the potential of becoming a new drug to inhibit TKI-resistance.

Clear cell renal cancer metastasis in the contralateral ureter: a case report

BackgroundClear cell renal carcinoma is known for its propensity for metastatic spread. Common sites of metastasis are the lungs, bones, lymph nodes, liver, adrenals and brain, but all organs can be affected. Contralateral ureteral metastasis is a rare phenomenon, and only a few cases have been reported in the literature.Case presentationWe present the case of a 58-year-old Caucasian patient with a single contralateral ureteral metastasis of a clear cell renal carcinoma.ConclusionUreteral metastasis of clear cell renal carcinoma is very rare, and there is no well-established treatment. For patients with low metastatic spread/volume, the aim should be to preserve kidney function, and thus metastasectomy should be considered.

Pancreatic Metastasis of Renal Cell Carcinoma: A Surgical Indication for a Disseminated Disease

Pancreatic metastasis (PM) of renal cancer is a rare condition. It is characterized by a long period after initial nephrectomy and a favorable prognosis compared to other pancreatic malignancies. Its diagnosis may confuse clinicians if the medical history is not known. In the era of targeted therapies for metastatic renal carcinoma, surgery stands as the best treatment option for PM of renal cancer. We report the case of a woman who underwent successfully left splenopancreatectomy for corporeal PM of renal cancer treated seven years ago. This case underlines the necessity of long-term follow-up of patients treated for kidney cancer.

Androgen receptor decreases renal cell carcinoma bone metastases via suppressing the osteolytic formation through altering a novel circEXOC7 regulatory axis.

BackgroundClear cell renal cell carcinoma (ccRCC) has gender differences, with the androgen receptor (AR) linked positively with metastasis to the lung. Its linkage to ccRCC bone metastases (RBMs), however, remains unclear.MethodsIn the current study, five human RCC and five RCC bone metastasis tissues were deeply sequenced using Arraystar human circRNA V2.0 microarray. We conducted gain‐of‐function screening in vitro and in vivo to elucidate the AR's role in the RBM. Loss/gain‐of‐function was also implemented to verify the roles of related non‐coding RNAs and proteins.ResultsWe uncovered that RBM also has a gender difference showing higher AR expression may be linked to fewer RBMs, which might involve suppressing osteolytic formation. Mechanism dissection indicates that AR can decrease the circular RNA EXOC7 (circEXOC7), expression via enhancing transcription of DHX9, a regulatory protein in circRNA biogenesis. The circEXOC7 can sponge/suppress miR‐149‐3p resulting in suppressing the CSF1 expression by directly binding to the 3′UTR region of CSF1 mRNA. Results from clinical epidemiological surveys also found that AR has a positive correlation with miR‐149‐3p and a negative correlation with CSF1 in AR‐positive ccRCC tissues. Preclinical studies with Balb/c nude mouse model also validated that targeting this newly verified AR/DHX9/circEXOC7/miR‐149‐3p/CSF1 signaling via altering circEXOC7 or AR could lead to suppressing the RBM progression.ConclusionsThese data showed that AR/DHX9/circEXOC7/miR‐149‐3p/CSF1 signaling acts as a valuable feature in the bone metastasis of renal cancer, which may benefit in suppressing the RBM progression.

Determination Of Risk Parameters In The Detection Of Asymptomatic Bone Metastases Of Kidney And Prostate Cancer

Using multivariate analysis to identify predictive risk parameters in the diagnosis of asymptomatic osteogenic metastasis of renal and prostate cancer. The work was based on the results of observations of 105 patients with a morphologically confirmed diagnosis of malignant neoplasm registered at the Republican Specialized Scientific and Practical Center of Oncology and Radiology (RSNPMTSO and R) and the Samarkand branch. In 62 patients with kidney cancer (RP) included in the study, the mean age of patients with RP was 58.3 years. 43 patients with prostate cancer (PC) were included in the study, the average age of patients with PC was 68 years. We analyzed such parameters as age, stage of the disease, timing of detection of bone metastasis (BM), prevalence, type and size of BM, as well as additional criteria: in case of prostate cancer - the size of the primary tumor and the degree of malignancy, in case of prostate cancer - the sum of points on the Gleason scale and the prostate -specific antigen (PSA). It was revealed that the highest risk in detecting BM in RP was noted for the stage of the disease, p = 0.006. Also, a high risk was associated with the size and grade of tumor malignancy, with CR at p = 0.006 and p = 0.008, respectively. Among the listed, the highest risk in detecting BM is observed in prostate cancer for the stage of the disease (p = 0.001). In addition, an increased risk was observed for the Gleason score and PSA level (p = 0.013 and p = 0.008, respectively). Thus, during the 2-year follow-up, BM most often develops in patients with kidney cancer at stage Tv-T3a stage and with grade G III and in patients with prostate cancer - in the presence of stage III with a Gleason score of ≥ 7 and a level PSA in the range of 21-50 ng / ml.

Metastatic renal cancer: real-world evidence from a large Italian claims database

Purpose: To assess the healthcare resources’ consumption and integrated costs of patients with renal cancer and new metastasis (mRCC), in the perspective of the Italian National Health System (NHS).
 Methods: From the ReS database, through the administrative data record linkage, adults with a primary/secondary hospital (ordinary/daily admissions) diagnosis (ICD9-CM code) of renal cancer and lymph node and/or distant metastases in the same hospital discharge (index date) were selected in 2015. Metastases were defined new if they were absent in the 2 previous years. Patients were described in terms of gender, age (mean ± SD) and comorbidities of interest. The 2-year survival and annual pharmacological treatments, hospitalization, outpatient specialist services and costs were analysed.
 Results: Out of >6 million adults in the 2015 ReS database, 133 (2.1 × 100,000) were hospitalized with a diagnosis of RCC and metastasis. Patients with new metastases were 63.2% (1.4 × 100,000; 73.8% males; mean age 68 ± 13). Hypertension was the most common comorbidity (70.2% of mRCC patients). The 2-year survival of mRCC patients was 26.2%. During 1-year follow-up, at least a drug was prescribed to 88.1% of mRCC patients (on average € 12,095/patient), 91.7% were hospitalized (€ 8,897/patient) and 82.1% entrusted the outpatient specialist care (€ 1,075/patient). The mean overall expenditure for the NHS was € 22,067 per capita.
 Conclusions: This study shows the mRCC burden on the Italian real clinical practice and its economic impact in the perspective of the NHS. Real-world analyses prove to be useful to concretely estimate the overall healthcare responsibility on patients affected by mRCC.

358 total laparoscopic pancreatoduodenectomy for patients with lesions of the head of the pancreas and periampullary area

Purpose: To show our experience in treatment patients with lesions of the head of the pancreas and the periampullary area by using a total laparoscopic approach. Methods: From January 2007 to December 2020 358 patients were taken for laparoscopic pancreaticoduodenectomy at the single center: Whipple procedure(n-271)and pylorus-preserving PD(n-88). There were 211 females and 147 males. The median age 62(range 34-82)years. BMI-26.4(1-98,2-121,3-64). Diagnosis: pancreatic carcinoma(n-160),low bile duct carcinoma(n-32),ampullary carcinoma(n-81),renal cancer metastasis(n-1),duodenal carcinoma(n-19),duodenal melanoma metastasis(n-1),ampullary adenoma(n-13),chronic pancreatitis(n-18),neuroendocrinetumor of the duodenum(n-3),solid pseudopapillary tumor(n-5),ampullary neuroendocrine tumor(n-8),low bile duct adenoma(n-2),intraductal papillary mucinous neoplasm(n-6),lymphoma(n-2),serous cystadenoma of the pancreas (n-1).In a retrospective study we analysed the main outcome measures:blood loss,operative time,length of hospital stay, postoperative complication according to Clavien-Dindo. Results: Median operative time was 423 (range 220-875)min and median blood loss was 294(range 10-2800)ml. Clavien - Dindo: IIIa - n49, IIIb - n36, IV - n12, V - n22. Clinically significant pancreatic fistula occurred in 74 cases (20,6%). Median length of postoperative hospital stay was 16(4-94) days. Conclusion: Totally laparoscopic pancreaticoduodenectomy is safe and effective procedure for patients with cancer of the biliopancreatoduodenal area. The results are comparable with results after open pancreatoduodenectomy. In spite of this, controlled multi-centric trials are needed.

Human circular RNA hsa_circRNA_101705 (circTXNDC11) regulates renal cancer progression by regulating MAPK/ERK pathway

ABSTRACT Circular RNAs (circRNAs) play essential roles in the progression of human tumors, including renal cell carcinoma (RCC). The present study aimed to explore the functions and potential mechanisms of human circular RNA hsa_circRNA_101705 (circTXNDC11) in RCC. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to measure circTXNDC11 expression in RCC tissues and cell lines. RNase R and actinomycin D assays were conducted to analyze the characteristic of circTXNDC11. Cell Counting Kit-8 (CCK-8) assay, colony formation assay, and transwell invasion assay were performed to assess cell proliferation and invasion abilities. Western blotting was applied to assess the levels of MEK and ERK proteins in RCC cells. Murine xenograft model assay was conducted to deduce the role of circTXNDC11 in vivo. The current data showed that circTXNDC11 was overexpressed in RCC tissues and cells. The overexpression of circTXNDC11 is linked to advanced TNM stage and lymph node metastasis of renal cancer. Knocking down circTXNDC11 suppressed cell proliferation and invasion in vitro and reduced tumor growth in vivo. Mechanistically, circTXNDC11 promoted RCC growth and invasion by activating the MAPK/ERK pathway. Thus, the current findings identified circTXNDC11 as a novel regulator of RCC tumorigenesis through the regulation of the MAPK/ERK pathway, offering a potential therapeutic target for RCC treatment.

MiR-155-5p promotes metastasis and epithelial-mesenchymal transition of renal cell carcinoma by targeting apoptosis-inducing factor.

Although renal cell carcinoma remains one of the most malignant cancers, our understanding of progression and recurrence of this disease is limited. The present study explored the precise role of miR-155-5p in renal cancer metastasis. The expression of miR-155-5p in renal carcinoma clinical tissues and cells was determined using quantitative real time-polymerase chain reaction. The role of miR-155-5p on tumor cell growth were examined using CCK-8 and colony formation assays. Transwell assay was utilized to identify the role of miR-155-5p on the invasion and migration of renal cancer cells. Markers of epithelial-mesenchymal transition were determined using western blot. The in vivo effects of miR-155-5p on renal cancer cell growth, apoptosis, and metastasis were explored using xenograft mice. Luciferase reporter assay was performed to identify the potential target of miR-155-5p. Levels of miR-155-5p were significantly elevated in renal cancer tissues and cell lines. Suppression of miR-155-5p decreased the growth, colony formation, migration, and invasiveness of renal cancer cells. In contrast, overexpression of miR-155-5p led to opposite effects on renal cancer cells. Mechanically, the apoptosis-inducing factor was identified as the target of miR-155-5p. Interference of miR-155-5p significantly increased mRNA and protein expression of the apoptosis-inducing factor, whereas overexpression of miR-155-5p remarkably suppressed the apoptosis-inducing factor levels in renal cancer cells. The xenograft model identified that suppression of miR-155-5p restrained tumor growth and promoted apoptosis, whereas overexpression of miR-155-5p decreased apoptosis and accelerated tumor growth. Moreover, the number of lung metastasis nodules were decreased following injection with anti-miR-155-5p transfected cells, whereas the nodules were remarkably increased after overexpression of miR-155-5p. In addition, in vitro and in vivo assays both confirmed that suppression of miR-155-5p increased the expression of E-cadherin and decreased levels of N-cadherin and Snail, whereas overexpression of miR-155-5p accelerated epithelial-mesenchymal transition progression in renal cancer cells. These findings demonstrate that miR-155-5p enhances metastasis and epithelial-mesenchymal transition by targeting the apoptosis-inducing factor, suggesting that miR-155-5p represents a novel therapeutic target for renal cancer.

Up-Regulation of miR-26a-5p Inhibits E2F7 to Regulate the Progression of Renal Carcinoma Cells.

BackgroundMetastasis is the main cause of renal cell carcinoma (RCC) tumor death, and effective inhibition of RCC metastasis is an essential means to meliorate the prognosis of RCC patients. MicroRNAs (miRs) have been proved to be stable and important biomarkers for several malignancies. This study is therefore set out to explore the metastasis-related miR and its mechanism in RCC.MethodsThe expression of miR-26a-5p in RCC was analyzed using the expression profile in the Cancer Genome Atlas (TCGA). MiR-26a-5p and E2F transcription factor 7 (E2F7) in RCC patients were detected by qRT-PCR. Cell Counting Kit-8 (CCK-8) was adopted to assess cell proliferation, Transwell was utilized to evaluate migration and invasion, and flow cytometry (FC) was used to determine apoptosis. Mouse cell-derived and patient-derived xenotransplantation models were established to evaluate the effect of miR-26a-5p on tumor growth and metastasis in vivo. The molecular mechanism of miR-26a-5p was analyzed by dual-luciferase reporter (DLR) gene analysis, qRT-PCR, and Western blot (WB) both in vivo and in vitro.ResultsMiR-26a-5p was reduced in renal carcinoma cells and may serve as a biomarker for renal cancer metastasis and prognosis. MiR-26a-5p up-regulation inhibited migration and invasion in renal cell lines and tumor metastasis in vivo. Bioinformatics target prediction and RNA-seq results showed that E2F7 was among the targets of miR-26a-5p and was significantly inhibited by miR-26a-5p in vivo and in vitro.ConclusionMiR-26a-5p presents low expression in RCC and promotes RCC cell apoptosis and prevents cells from proliferating and invading by targeting E2F7, which is a promising therapeutic target for RCC.

Transformable Dual-Inhibition System Effectively Suppresses Renal Cancer Metastasis through Blocking Endothelial Cells and Cancer Stem Cells.

Tumor vasculature and cancer stem cells (CSCs) accelerate the development of metastatic renal cancer. Dual inhibition of vascular endothelium and CSCs is still a challenge due to their different pathological features. Herein, a transformable dual-inhibition system (TDS) based on a self-assembly peptide is proposed to construct nanofibrous barriers on the cell membrane in situ, which contributes to 1) reducing endothelial permeability and angiogenesis; and 2) inhibiting stemness and metastasis of CSCs in renal cancer. TDS specifically targets overexpressed receptor CD105 that provides the possibility to modulate both endothelial cells and CSCs for cancer therapy. Subsequently, owing to ligand-receptor interaction-induced transformation, the nanofibers form a barrier on the cell membrane. For vascular endothelium, TDS reduces the vascular permeability to 67.0% ± 4.7% and decreases angiogenesis to 62.0% ± 4.0%, thereby preventing the renal cancer metastasis. For human-derived CSCs, TDS inhibits stemness by reducing endogenic miR-19b and its transportation via CSCs-derived exosomes, which increases PTEN expression and consequently suppresses CSCs-mediated metastasis. In patient-derived xenograft mice, TDS significantly inhibits the tumorigenesis and angiogenesis. It also reduces the metastatic nodules in lung 5.0-fold compared with the control group. TDS opens up a promising avenue for suppressing the metastasis of cancer.

Abstract 4702: DNA methylation enhances apoptosis resistance of renal cancer cells through the control of mitochondria related gene expression

Abstract Many gene alterations have been identified in the onset of renal carcinogenesis. However, molecular alterations might be added to renal cancer cells during the progression. In order to uncover additional molecular alterations, we established highly malignant cancer cells which possess identical background to original cancer cells, and analyzed them in the present study. Since our previous works demonstrated that interaction with cancer microenvironment aids cancer cells with malignant trait through “education” and “selection”, serial orthotopic transplantation was utilized. First, parental human clear cell renal cell carcinoma cells, OS-RC-2, were subjected to serial orthotopic transplantation. Then, novel derivatives were obtained from resulting primary renal tumors. These derivatives formed primary renal tumor faster than parental cells and exhibited increased lung metastasis, suggesting that these derivatives were defined as “highly malignant cancer cells”. Next, we tried to identify the underlying molecular mechanism(s) for renal cancer progression through the characterization of highly malignant cancer cells. Gene expressions in each cell were profiled using RNA-sequencing, and these analyses revealed that expression of several genes associated with mitochondrial functions were dramatically down-regulated in highly malignant cancer cells. Since mitochondrial electron transport chain triggers apoptotic cell death, decrease of these genes may contribute to suppression of apoptosis of highly malignant cancer cells. Cell culture and in vivo experiments demonstrated that mitochondrial dysfunction is responsible for increased survival of renal cancer cells and cancer metastasis. Finally, regulatory mechanism of downregulation of these mitochondria-related genes was analyzed. Bisulfite sequencing analysis revealed that the downregulation may occur by DNA hypermethylation of CpG islands in the promoter regions in renal cancer cells.Taken together, these findings suggested that renal cancer cells acquire additional anti-apoptotic ability through the DNA methylation during the interactions with renal microenvironment, which may in turn lead to the cancer progression and metastasis. We are currently investigating whether the effect of anti-cancer reagent is enhanced in the presence of DNA methylation inhibitors. Citation Format: Kosuke Miyakuni, Jun Nishida, Shogo Ehata, Kohei Miyazono. DNA methylation enhances apoptosis resistance of renal cancer cells through the control of mitochondria related gene expression [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4702.

SPARC is a key mediator of TGF-β-induced renal cancer metastasis.

Aberrant expression of transforming growth factor-β1 (TGF-β1) is associated with renal cell carcinoma (RCC) progression by inducing cancer metastasis. However, the downstream effector(s) in TGF-β signaling pathway is not fully characterized. In the present study, the elevation of secreted protein acidic and rich in cysteine (SPARC) as a TGF-β regulated gene in RCC was identified by applying differentially expressed gene analysis and microarray analysis, we further confirmed this result in several RCC cell lines. Clinically, the expression of these two genes is positively correlated in RCC patient specimens. Furthermore, elevated SPARC expression is found in all the subtypes of RCC and positively correlated with the RCC stage and grade. In contrast, SPARC expression is inversely correlated with overall and disease-free survival of patients with RCC, suggesting SPARC as a potent prognostic marker of RCC patient survival. Knocking down SPARC significantly inhibits RCC cell invasion and metastasis both in vitro and in vivo. Similarly, in vitro cell invasion can be diminished by using a specific monoclonal antibody. Mechanistically, SPARC activates protein kinaseB (AKT) pathway leading to elevated expression of matrix metalloproteinase-2 that can facilitate RCC invasion. Altogether, our data support that SPARC is a critical role of TGF-β signaling network underlying RCC progression and a potential therapeutic target as well as a prognostic marker.