Zongming Lin

Klotho suppresses tumor progression via inhibiting PI3K/Akt/GSK3β/Snail signaling in renal cell carcinoma

Klotho is an anti‐aging protein predominantly expressed in renal tubular epithelial cells. Although Klotho was recently identified as a tumor suppressor gene in a variety of cancers, the potential role and molecular events for Klotho in renal cell carcinoma (RCC) remain obscure. In the present study, immunohistochemical staining in tissue microarrays containing 125 RCC samples showed that intratumoral Klotho levels were negatively correlated with tumor size, TNM stage and nuclear grade. The overall survival rate of RCC patients with high Klotho expression was significantly higher than that of patients with low Klotho expression. Functional analysis after gain and loss of Klotho expression revealed that Klotho blunted epithelial‐mesenchymal transition and cellular migration and invasion in RCC. Also, no alteration of α‐2,6‐sialidase activity was found after Klotho overexpression in RCC. The molecular signals for this phenomenon involved the Klotho‐mediated inhibition of PI3K/Akt/GSK3β/Snail pathway. Importantly, compared to localized RCC tissues, advanced RCC tissues exhibited low Klotho expression accompanied with high pAkt and Snail expression. These results indicate Klotho acts as a tumor suppressor by inhibiting PI3K/Akt/GSK3β/Snail signaling, thus suppressing epithelial‐mesenchymal transition and tumor migration and invasion during RCC progression. As a result, Klotho might be used as a potential therapy for advanced RCC.

Sunitinib induces cellular senescence via p53/Dec1 activation in renal cell carcinoma cells

Although multitargeted tyrosine kinase inhibitor sunitinib has been used as first‐line therapeutic agent against metastatic renal cell carcinoma (mRCC), the molecular mechanism and functional role per se for its therapeutic performance remains obscure. Our present study revealed that sunitinib‐treated RCC cells exhibit senescence characteristics including increased SA‐β‐gal activity, DcR2 and Dec1 expression, and senescence‐associated secretary phenotype (SASP) such as proinflammatory cytokines interleukin (IL)‐1α, IL‐6 and IL‐8 secretion. Moreover, sunitinib administration also led to cell growth inhibition, G1‐S cell cycle arrest and DNA damage response in RCC cells, suggesting therapeutic significance of sunitinib‐induced RCC cellular senescence. Mechanistic investigations indicated that therapy‐induced senescence (TIS) following sunitinib treatment mainly attributed to p53/Dec1 signaling activation mediated by Raf‐1/NF‐κB inhibition in vitro. Importantly, in vivo study showed tumor growth inhibition and prolonged overall survival were associated with increased p53 and Dec1 expression, decreased Raf‐1 and Ki67 staining, and upregulated SA‐β‐gal activity after sunitinib treatment. Immunohistochemistry analysis of tumor tissues from RCC patients receiving sunitinib neoadjuvant therapy confirmed the similar treating phenotype. Taken together, our findings suggested that sunitinib treatment performance could be attributable to TIS, depending on p53/Dec1 activation via inhibited Raf‐1/nuclear factor (NF)‐κB activity. These data indicated potential insights into therapeutic improvement with reinforcing TIS‐related performance or overcoming SASP‐induced resistance.

Clinical significance of tumor-derived IL-1β and IL-18 in localized renal cell carcinoma: Associations with recurrence and survival

PURPOSE Interleukin-1β (IL-1β) and IL-18 are products of activated inflammasomes that play central roles in innate immunity and inflammation. This study was aimed to determine the effect of tumor-derived IL-1β and IL-18 on recurrence and survival of patients with localized clear cell renal cell carcinoma (ccRCC) following surgery. METHODS We retrospectively enrolled 267 patients with localized ccRCC undergoing nephrectomy at a single center. Clinicopathologic features, recurrence-free survival (RFS), and overall survival (OS) were recorded. IL-1β and IL-18 levels were assessed by immunohistochemistry in tumor tissues. The Kaplan-Meier method was used to compare survival curves. Cox regression models were used to analyze the effect of prognostic factors on RFS and OS. Concordance index was calculated to assess predictive accuracy. RESULTS Both high IL-1β and high IL-18 levels were associated with increased risk of recurrence (P<0.001 and P<0.001, respectively) and reduced survival (P<0.001 and P = 0.001, respectively). The combination of IL-1β and IL-18 expression (IL-1β/IL-18 signature) could further refine prognostic stratification. Multivariate analyses confirmed that IL-1β/IL-18 signature was an independent prognostic factor for RFS and OS (P = 0.005 and P = 0.044, respectively). The predictive accuracy of well-established prognostic models improved when the IL-1β/IL-18 signature was added. Notably, the improvement in prediction was mainly observed in patients with low-risk disease. CONCLUSIONS The combined high expression of IL-1β and IL-18 is an independent predictor for poor prognosis in patients with localized ccRCC, and the prognostic value is more pronounced in patients with low-risk disease.

Notch1 activation promotes renal cell carcinoma growth via PI3K/Akt signaling

Both the Notch1 and PI3K/Akt pathways are aberrantly activated in clear cell renal cell carcinoma (CCRCC) and involved in the tumorigenesis. The aim of this study was to test our hypothesis that elevated Notch1 signaling activity exerts its growth‐promoting effects via the PI3K/Akt pathway in CCRCC. To investigate the relationship between the two pathways, we enhanced and suppressed the Notch1 activity respectively in a CCRCC cell line through diverse means, and then evaluated ensuing phosphorylated Akt (pAkt) levels. To further study their collaboration in promoting tumor growth, cell proliferation assay, colony formation assay and cell cycle analysis were conducted under several different conditions. Immunostaining of the tissue microarrays was used to determine whether the phenomena we observed also existed in vivo. The results showed that Notch1 signaling was activated in CCRCC tissue samples and cell lines. Notch1 activation increased CCRCC cell proliferation, enhanced anchorage‐independent growth, and accelerated G1/S cell cycle progression. Such effects of the Notch1 signaling were, at least in part, mediated by the PI3K/Akt pathway. Correlations between Notch1, pAkt and Ki‐67 protein levels in tissue microarrays reinforced our in vitro findings. Taken together, the current study established a functional link between the Notch1 and PI3K/Akt pathways in CCRCC. (Cancer Sci 2012; 103: 1253–1258)

Overexpression of HOXC11 homeobox gene in clear cell renal cell carcinoma induces cellular proliferation and is associated with poor prognosis

Novel evidence has confirmed the involvement of dysregulated expression of HOX genes in cancer. HOX genes are a family of 39 transcription factors, divided in four clusters (HOXA to HOXD), that during normal development regulate cell proliferation and specific cell fate. The aim of this study was to investigate whether genes of the HOXC cluster might play a role in renal cancer. The expression of HOXC11 was detected through polymerase chain reaction and immunohistochemical staining, and we demonstrated that HOXC11 was significantly higher in renal cell carcinoma (RCC) compared to normal kidney tissue. We further demonstrated that HOXC11 overexpression in HK-2 human epithelial cell line promoted proliferation, whereas downregulation of HOXC11 endogenous levels in human RCC cells (Caki-2 cells) decreased proliferation. In RCC, expression of HOXC11 and Ki67, a marker of proliferation, correlates strongly with each other (rs = 0.47, p < 0.003). High immunohistochemical expression of HOXC11 was correlated with T stage (p = 0.06), N stage (p = 0.07), disease stage (p = 0.08), and Ki67 expression (p = 0.07), and patients with tumors showing high number of HOXC11-positive cells had shorter overall survival (p = 0.08) and shorter progression-free survival after treatment (p = 0.08) compared with patients with tumors exhibiting low amount of HOXC11-positive cells. Our data suggest that HOXC11 may contribute to RCC carcinogenesis by increasing tumor cell proliferation and imply that HOXC11 may be an important determinant of RCC patient prognosis.

Increased expression of Chitinase 3-like 1 and microvessel density predicts metastasis and poor prognosis in clear cell renal cell carcinoma

Increasing evidence demonstrated that Chitinase 3-like 1 (hereafter termed CHI3L1 or YKL-40) was highly expressed and tightly associated with human tumor development and progression. However, its precise role in clear cell renal cell carcinoma (hereafter termed RCC) remains to be delineated. In the present study, we investigated the relationship between CHI3L1 expression and microvessel density (MVD), a reflection of angiogenesis, with metastasis and prognosis in patients with clear cell renal cell carcinoma (RCC). Formalin-fixed, paraffin-embedded tissue sections of clear cell RCC from 73 patients who had undergone radical nephrectomy were stained immunohistochemically with specific antibodies against CHI3L1 and CD34. CHI3L1 immunostaining was semi-quantitatively estimated based on the proportion (percentage of positive cells) and intensity. MVD was determined with CD34-stained slides. The expression pattern of CHI3L1 and MVD was compared with the clinicopathological variables. Twenty patients had either synchronous or metachronous metastases and 12 died during the follow-up. CHI3L1 intensity was significantly correlated with tumor size (P = 0.005), TNM stage (P = 0.027), M stage (P = 0.011), grade (P = 0.014), and metastasis (synchronous or metachronous; P < 0.001). The CHI3L1 proportion (P = 0.038) and MVD (P = 0.012) were significantly correlated with metastasis. MVD was correlated with CHI3L1 intensity (r = 0.376, P = 0.001) and CHI3L1 proportion (r = 0.364, P = 0.002). There was no difference in the expression of CHI3L1 and MVD between primary and metastatic sites. The survival of patients with higher CHI3L1 intensity was significantly worse than that of patients with lower CHI3L1 intensity. Multivariate analyses indicated that only M stage was an independent prognostic factor for cancer-specific survival and CHI3L1 expression was not an independent factor. Taken altogether, increased expression of CHI3L1 and MVD is associated with metastasis and a worse prognosis in clear cell RCC. CHI3L1 expression is correlated with MVD. The results suggest that CHI3L1 may be important in the progression and angiogenesis of clear cell RCC and CHI3L1 might be a novel strategy for therapy of the patients with RCC.

Tumor-infiltrating neutrophils predict benefit from adjuvant chemotherapy in patients with muscle invasive bladder cancer

ABSTRACT Growing evidence shows tumor-infiltrating neutrophils (TINs) involvement in tumorigenesis. The objective of this study is to assess the prognostic effect of TINs and its impact on adjuvant chemotherapy benefits in muscle invasive bladder cancer (MIBC). A total of 142 MIBC patients from Zhongshan Hospital, 119 MIBC patients from FUSCC, and 405 MIBC patients from TCGA cohort were enrolled in the study. TINs were evaluated by immunohistochemical staining of CD66b or the CIBERSORT method. Patients with high TINs had a significantly poorer overall survival (p = 0.001, p < 0.001, and p = 0.002, respectively) in the three sets. In the multivariate analysis, the presence of high TINs (HR = 2.122, p = 0.007; HR = 3.807, p < 0.001; HR = 2.104, p = 0.001; respectively) was identified as an independent prognostic factor for overall survival in the three sets. More importantly, Low TINs patients had significantly longer overall survival in patients without ACT in the three sets. Gene set enrichment analysis showed that lymphocyte activation (p < 0.001) and T cell activation (p = 0.008) were significantly enriched in the low TINs group. In addition, TINs were negatively correlated with CD8+ T cells, suggesting that the status of high-TINs was linked to the status of immunosuppression in MIBC. TINs could be used as independent prognostic factor. Low TINs identified a subgroup of MIBC patients who appeared to benefit from adjuvant chemotherapy. Incorporation of TINs into TNM system could further stratify patients with different prognosis.

Prognostic value of preoperative lymphocyte to monocyte ratio in patients with nonmetastatic clear cell renal cell carcinoma

Growing evidence indicates that systemic inflammation involves in cancer development and progression. Preoperative lymphocyte to monocyte ratio (LMR) has been estimated as an independent prognostic factor of various cancers. We investigated the prognostic value of LMR in nonmetastatic clear cell renal cell carcinoma (ccRCC) patients after surgery. We retrospectively recruited 430 consecutive patients with nonmetastatic ccRCC (T1-3N0M0) who underwent curative nephrectomy between 2008 and 2009 at a single center in China. Lymphocyte and monocyte counts were obtained at hospitalization before surgery. Preoperative LMR as a continuous variable and as a dichotomized variable at a level of 3.25, which was the 25th percentile value, were analyzed in unvariable and multivariable Cox regression models, respectively. Concordance index (C-index) was calculated to assess predictive accuracy. Kaplan-Meier method was applied to compare survival curves. As both of the continuous and dichotomized variable, decreased preoperative LMR was proven to be independent prognostic factors of recurrence-free survival (P = 0.039 and P = 0.003, respectively) and overall survival (P = 0.002 and P < 0.001, respectively). Further examination revealed that the dichotomized LMR could enhance the predictive accuracy of each of the existing prognostic models among intermediate-risk to high-risk patients. The preoperative LMR is an independent prognostic factor of recurrence-free survival and overall survival for nonmetastatic ccRCC patients after surgery, and it can be used in tandem with established prognostic systems to further enhance outcome prediction in intermediate-risk to high-risk patients.

CXC chemokine receptor 2 is associated with postoperative recurrence and survival of patients with non-metastatic clear-cell renal cell carcinoma

BACKGROUND Aberrant CXC chemokine receptor 2 (CXCR2) expression has been shown to promote angiogenesis and proliferation in renal cell carcinoma (RCC). Our current study aims to evaluate the prognostic significance of CXCR2 in patients with non-metastatic clear-cell renal cell carcinoma (ccRCC). METHODS We retrospectively enrolled 375 patients with non-metastatic ccRCC undergoing nephrectomy at Zhongshan Hospital, Fudan University between 2003 and 2008. The cohort was split into a training set (n=184) and a validation set (n=191). CXCR2 expression was assessed by immunohistochemical staining and its association with clinicopathologic features and prognosis were evaluated. RESULTS CXCR2 expression was significantly associated with tumour size (P=0.036 and P=0.016, respectively) and Fuhrman grade (P=0.009 and P=0.001, respectively) in the training and validation sets. Moreover, high CXCR2 expression indicated poor overall survival (OS) (P<0.001 and P=0.001, respectively) and recurrence-free survival (P<0.001 and P<0.001, respectively) in the training and validation sets. The incorporation of CXCR2 into the T stage and Fuhrman grade would help to refine individual risk stratification. Furthermore, CXCR2 expression was identified as an independent adverse prognostic factor for survival (P<0.001) and recurrence (P<0.001). A predictive nomogram was generated with identified independent prognosticators to assess patient recurrence-free survival at 5 and 10 years. CONCLUSIONS CXCR2 is a potential independent adverse prognostic biomarker for recurrence and survival of patients with non-metastatic ccRCC after nephrectomy.

Impact of an Altered PROX1 Expression on Clinicopathology, Prognosis and Progression in Renal Cell Carcinoma

The transcription factor PROX1 (prospero homeobox 1) has a critical role in the development of various organs, and has been implicated in both oncogenic and tumor-suppressive functions in human cancers. However, the role of PROX1 in the development of renal cell carcinomas (RCCs) has not yet been studied. Here, we reported that PROX1 expression was decreased in human RCC tissues compared with adjacent normal tissues. In RCC tissues, however, poorly differentiated RCC expressed higher PROX1 levels compared with well-differentiated RCC. In addition, the PROX1 immunostaining levels were positively correlated with tumor nuclear grade and lymph node metastasis. Further, high PROX1 expression indicated poor survival for patients. These findings imply that in the different developmental stages of RCC, PROX1 may exert distinct functions according to the specific microenvironment of tumor. Moreover, in vitro experiments revealed that PROX1 overexpression enhanced the proliferation and migration of RCC cells; conversely, PROX1 depletion by siRNA attenuated the proliferation and migration of RCC cells. Collectively, these observations suggest that PROX1 plays an important role in RCC development and progression, and PROX1 may be a novel target for prevention and treatment of RCC.