Fumarate inhibits PTEN to promote tumorigenesis and therapeutic resistance of type2 papillary renal cell carcinoma.

Fumarate is an oncometabolite. However, the mechanism underlying fumarate-exerted tumorigenesis remains unclear. Here, utilizing human type2 papillary renal cell carcinoma (PRCC2) as a model, we show that fumarate accumulates in cells deficient in fumarate hydratase (FH) and inhibits PTEN to activate PI3K/AKT signaling. Mechanistically, fumarate directly reacts with PTEN at cysteine 211 (C211) to form S-(2-succino)-cysteine. Succinated C211 occludes tethering of PTEN with the cellular membrane, thereby diminishing its inhibitory effect on the PI3K/AKT pathway. Functionally, re-expressing wild-type FH or PTEN C211S phenocopies an AKT inhibitor in suppressing tumor growth and sensitizing PRCC2 to sunitinib. Analysis of clinical specimens indicates that PTEN C211 succination levels are positively correlated with AKT activation in PRCC2. Collectively, these findings elucidate a non-metabolic, oncogenic role of fumarate in PRCC2 via direct post-translational modification of PTEN and further reveal potential stratification strategies for patients with FH loss by combinatorial AKTi and sunitinib therapy.

A Nomogram Including Sarcopenia for Predicting Progression-Free Survival in Patients with Localized Papillary Renal Cell Carcinoma: A Retrospective Cohort Study.

BACKGROUND: Because of to the removal of subclassification of papillary renal cell carcinoma (pRCC), the survival prognostification of localized pRCC after surgical treatment became inadequate. Sarcopenia was widely evaluated and proved to be a predictive factor for prognosis in RCC patients. Therefore, we comprehensively investigated the survival prediction of the body composition parameters for localized pRCC. METHODS: Patients pathologically diagnosed with pRCC between February 2012 and February 2022 in our center were enrolled. The body composition parameters, including skeletal muscle index (SMI), subcutaneous adipose tissue (SAT), and perirenal adipose tissue (PRAT), were measured by the images of preoperative computed tomography (CT). The primary outcome was set as progression-free survival (PFS), and the cutoff values of body composition parameters were calculated by using the Youden from receiver operating characteristic curve (ROC) curves. Univariate and multivariate Cox proportional regression analyses were performed to explore independent risk factors for survival prediction. Then, significant factors were used to construct a prognostic nomogram. The performance of the nomogram was evaluated by Harrell's C-index, calibration curves and time-dependent ROC curves. RESULTS: A total of 105 patients were enrolled for analysis. With a median follow-up time of 30.48 months, 25 (23.81%) patients experienced cancer progression. The percentage of sarcopenia was 74.29%. Univariate Cox analysis identified that gender, PRAT, SAT, skeletal muscle (SM), sarcopenia, surgical technique, and tumor diameter were associated with progression. Further multivariate analysis showed that sarcopenia (hazard ratio [HR] 0.15, 95% confidence interval [CI] 0.03-0.66), SAT (HR 6.36, 95% CI 2.39-16.93), PRAT (HR 4.66, 95% CI 1.77-12.27), tumor diameter (HR 0.35, 95% CI 0.14-0.86), and surgical technique (HR 2.85, 95% CI 1.06-7.64) were independent risk factors for cancer progression. Then, a prognostic nomogram based on independent risk factors was constructed and the C-index for progression prediction was 0.831 (95% CI 0.761-0.901), representing a reasonable discrimination, the calibration curves, and the time-dependent ROC curves verified the good performance of the nomogram. CONCLUSIONS: A prognostic nomogram, including sarcopenia, SAT, PRAT, tumor diameter, and surgical technique, was constructed to calculate the probability of progression for localized pRCC patients and needs further external validation for clinical use in the future.

Identification of PANoptosis-related signature reveals immune infiltration characteristics and immunotherapy responses for renal cell carcinoma.

PANoptosis is a specific type of inflammatory programmed cell death (PCD) modality that can be involved in three key modes of cellular programmed cell death-pyroptosis, apoptosis and necroptosis. We analyzed PANoptosis activity in three common renal cell carcinoma subtypes (Clear cell renal cell carcinoma, Papillary renal cell carcinoma, and Chromophobe renal cell carcinoma) separately and constructed a new PANoptosis immunity index (PANII). In three renal cell carcinomas, we found that PANII was an effective predictor of immunotherapy efficacy in KIRC, KIRP and KICH, and the high PANII group was characterized by high immune infiltration and sensitivity to immunotherapy, while the low PANII group was prone to immune escape and immunotherapy resistance. We performed molecular docking prediction of each core protein comprising PANII and identified natural small molecule compounds with the highest affinity to target proteins. In addition, we found that down-regulation of PYCARD inhibited the proliferation and migration of renal clear cell carcinoma cells by in vitro functional assays, suggesting that PYCARD could be a novel target for renal clear cell carcinoma therapy. Our findings that the PANoptosis characterization-based index (PANII) helps to elucidate the tumor microenvironmental features of three common renal cell carcinoma subtypes and identify patient populations that will benefit from immunotherapy, providing a new tool for the clinical diagnosis and treatment of patients with intermediate- and advanced-stage renal cell carcinoma.

Construction and Validation of a Mutation-Related Model in Papillary Renal Cell Carcinoma and Associated Immune Infiltration.

BACKGROUND: To improve the clinical evaluation of the prognosis of papillary renal cell carcinoma (PRCC), we screened a model to predict the survival of patients with mutations in related genes. METHODS: We downloaded RNA sequencing information from all patients with PRCC in TCGA. We first analyzed the differences in genes and the enrichment of these differences. Then, by selecting mutant genes, constructing a protein-protein interaction network, least absolute shrinkage and selection operator regression, and multivariable Cox regression, a prognosis model was constructed. Additionally, the model was validated using external data sets. We analyzed the immune infiltration of PRCC and the correlation between the model and popular targets. Finally, we performed tissue microarray analysis and immunohistochemistry to verify the expression levels of the three genes. RESULTS: We constructed a three-gene (never in mitosis gene A-related kinase 2 [NEK2], centromere protein A [CENPA], and GINS complex subunit 2 [GINS2]) model. The verification results indicated that the model had a good prediction effect. We also developed a visual nomogram. Enrichment analysis revealed the major pathways involved in muscle system processes. Immunoassays showed that the expression level of CENPA was positively correlated with PD-1 and CTLA4 expression levels. Immunohistochemical and tissue microarray results showed that these three genes were highly expressed in PRCC, which was consistent with the predicted results in the database. CONCLUSION: We constructed and verified a three-gene model to predict the patient survival. The results show that the model has a good prediction effect.

Papillary renal neoplasm with reverse polarity is biologically and clinically distinct from eosinophilic papillary renal cell carcinoma.

Papillary renal neoplasm with reverse polarity (PRNRP) is a recently described indolent entity with distinct features and its recognition from other oncocytic/eosinophilic papillary renal cell carcinoma (ePRCC) has important prognostic implications. ABCC2, a renal drug transporter, is overexpressed in aggressive PRCCs. In this study, we compared the clinicopathological parameters and the biological ABCC2 expression between PRNRP and ePRCC. PRNRP (n = 8) and ePRCC (n = 21) cases were selected from resection specimens and corresponding clinicopathological data were collected. ABCC2 immunohistochemical (IHC) staining was performed and ABCC2 staining patterns were classified as negative, cytoplasmic, and brush-border. RNA in-situ hybridization (ISH) was used to assess ABCC2 transcript levels. All eight PRNRP cases had weak cytoplasmic ABCC2 IHC reactivity; however, they showed no detectable ABCC2 transcripts on RNA ISH. In comparison, 76% (16/21) of ePRCCs showed ABCC2 IHC brush-border expression and significantly higher ABCC2 RNA ISH transcript levels (p < 0.001). Additionally, the ePRCC group showed a significantly larger tumor size (p = 0.004), higher WHO/ISUP grade (p < 0.001), and stage (p = 0.044). None of the PRNRP cases showed disease progression, while 9.5% (2/21) ePRCCs had disease progression. PRNRP is clinically and biologically distinct from ePRCC. Hence, it is crucial to differentiate between these two entities, particularly in needle core biopsies.

An epidemiological and clinicopathological study of type 1 vs. type 2 morphological subtypes of papillary renal cell carcinoma- results from a nation-wide study covering 50 years in Iceland.

INTRODUCTION: Papillary renal cell carcinoma (pRCC) is the second most common histology of renal cell carcinoma (RCC), accounting for 10-15% of cases. Traditionally, pRCC is divided into type 1 and type 2, although this division is currently debated as a prognostic factor of survival. Our aim was to investigate the epidemiology and survival of the pRCC subtypes in a whole nation cohort of patients during a 50-year period. MATERIALS AND METHODS: A Population based retrospective study including consecutive cases of RCC in Iceland from 1971-2020. Comparisons were made between histological classifications of RCC, with emphasis on pRCC subtypes (type 1 vs. 2) for outcome estimation. Changes in RCC incidence were analyzed in 5-year intervals after age standardization. The Kaplan-Meier method and Cox regression were used for outcome analysis. RESULTS: A total of 1.725 cases were identified, with 74.4%, 2.1% and 9.2% having clear cell (ccRCC), chromophobe (chRCC), and pRCC, respectively. The age standardized incidence (ASI) of pRCC was 1.97/100.000 for males and 0.5/100.000 for females, and the proportion of pRCC increased from 3.7% to 11.5% between the first and last intervals of the study (p < 0.001). Age standardized cancer specific mortality (ASCSM) of pRCC was 0.6/100.000 and 0.19/100.000 for males and females, respectively. The annual average increase in ASI was 3.6% for type 1 pRCC, but the ASI for type 2 pRCC and ASCSM for both subtypes did not change significantly. Male to female ratio was 4.4 for type 1 pRCC and 2.3 for type 2. The average tumor size for type 1 and 2 was 58.8 and 73.7 mm, respectively. Metastasis at diagnosis was found in 8.7% in the type 1 pRCC, compared to 30.0% of patients with type 2 pRCC (p < 0.001). Estimated 5-year cancer-specific survival (CSS) were 94.4%, 80.7%, and 69.3% for chRCC, pRCC and ccRCC, respectively (p < 0.001). For the pRCC subtypes, type 1 was associated with better 5-year CSS than type 2 (86.3% vs. 66.0%, p < 0.001), although this difference was not significant after adjusting for cancer stage and grading. CONCLUSIONS: pRCC histology was slightly less common in Iceland than in other countries. Males are more than three times more likely to be diagnosed with pRCC, compared to other RCC histologies. The subtype of pRCC was not found to be an independent risk factor for worse survival, and as suggested by the most recent WHO Classification of Urinary Tumors, grade and TNM-stage seem to be the most important factors for estimation of survival for pRCC patients.

Changes in outcome of patients with advanced non-clear cell renal cell carcinoma from the tyrosine kinase inhibitor era to the immuno-oncology era.

BACKGROUND: The therapeutic benefit of immuno-oncology (IO) therapy for patients with advanced non-clear-cell renal cell carcinoma (nccRCC) remains unclear. PATIENTS AND METHODS: We reviewed clinical data from 93 patients with advanced nccRCC who received first-line systemic therapy including IO combination therapy and tyrosine kinase inhibitor (TKI) monotherapy at our affiliated institutions. Patients were divided based on the period when the treatment was implemented as the standard of care into the IO and TKI eras. Survival and tumor response outcomes were compared between the IO and TKI eras. RESULTS: Of the 93 patients, 50 (54%) and 43 (46%) were categorized as IO era and TKI era groups, respectively. Progression-free survival (PFS) and overall survival (OS) were significantly longer in the IO era than in the TKI era (median PFS: 8.97 vs. 4.96 months, p = 0.0152; median OS: 38.4 vs. 13.5 months, p = 0.0001). After the adjustment using other covariates, the treatment era was an independent factor for PFS (hazard ratio: 0.59, p = 0.0235) and OS (hazard ratio: 0.27, p < 0.0001). Objective response and disease control rates was not significantly different between the treatment eras (26% vs. 16.3%, p = 0.268; 62% vs. 62.8%, p = 0.594). CONCLUSION: The implementation of IO therapy was significantly associated with longer survival in the nccRCC population. Further studies are needed to establish a more effective treatment strategy in this population using multiple regimens of IO combination therapy.

Hereditary papillary renal cell carcinoma.

Hereditary papillary renal cell carcinoma (HPRCC) is an autosomal dominant syndrome characterized by the occurrence of bilateral and multifocal, classic type papillary renal cell carcinomas. In the recent decades, extensive molecular studies have narrowed the molecular underpinnings of this syndrome to missense mutations in tyrosine kinase domain of MET proto-oncogene. Although MET mutations are specific to HPRCC, it has been found in sporadic papillary renal cell carcinomas and as recently reported, in biphasic squamoid alveolar variant of papillary renal cell carcinoma. Dual MET/VEGFR2 kinase inhibitor and tyrosine kinase inhibitors have shown promising results in systemic therapy for HPRCC.

Diagnostic value of imaging in patients with clear cell papillary renal cell carcinoma: A case series and literature review.

Clear cell papillary renal cell carcinoma (CCPRCC) is a newly classified renal cell carcinoma with a low degree of malignancy. Its imaging features have not been studied deeply. Therefore, we reviewed the imaging features of CCPRCC. Solid CCPRCC shows high echo or isoecho mass on conventional ultrasound. Contrast enhanced ultrasound shows "fast forward and slow backward, uneven high enhancement". Computed tomography shows high enhancement and maximum enhancement in the cortical-medullary phase. Magnetic resonance imaging shows slightly low T1WI and high T2WI. This article aims to improve the understanding of CCPRCC by clinical radiologists and promote the accurate.

Association between PD-L1 Expression and the Prognosis and Clinicopathologic Features of Non-Clear Cell Renal Cell Carcinoma.

PD-L1 is one of the two programmed cell death 1 (PD-1) ligands and a part of an immune checkpoint system (PD-1/PD-L1) with widespread clinical application. The aim of this study was to investigate PD-L1 expression and its association with clinicopathological and prognostic significance in non-clear cell renal cell carcinoma (non-ccRCC) patients. A total of 41 papillary (pRCC) and 20 chromophobe (chRCC) RCC tumors were examined for PD-L1 expression by immunohistochemistry in the cancer cells and tumor-infiltrating mononuclear cells (TIMCs). PD-L1 positivity was detected in 36.6% pRCC and 85.0% chRCC cancer cells, while PD-L1 positivity was observed in 73.2% pRCC and 50.0% chRCC TIMCs. PD-L1 positivity in both pRCC and chRCC tumor cells was not correlated with any of the examined clinicopathological features, while PD-L1 positivity in TIMCs was associated with the age of patients with pRCC. During follow-up, the death was documented among 6 patients with pRCC. Papillary RCC patients with PD-L1-positive tumor cells were significantly associated with an increased risk of death compared with patients with PD-L1-negative cancer cells. A similar trend was observed when comparing PD-L1 expression in TIMCs. However, no differences in overall survival for PD-L1-positive pRCC patients with compared to PD-L1-negative patients were observed in tumor cells or TIMCs.

Advances in Molecular Mechanisms of Kidney Disease: Integrating Renal Tumorigenesis of Hereditary Cancer Syndrome.

Renal cell carcinoma (RCC) comprises various histologically distinct subtypes, each characterized by specific genetic alterations, necessitating individualized management and treatment strategies for each subtype. An exhaustive search of the PubMed database was conducted without any filters or restrictions. Inclusion criteria encompassed original English articles focusing on molecular mechanisms of kidney cancer. On the other hand, all non-original articles and articles published in any language other than English were excluded. Hereditary kidney cancer represents 5-8% of all kidney cancer cases and is associated with syndromes such as von Hippel-Lindau syndrome, Birt-Hogg-Dubè syndrome, succinate dehydrogenase-deficient renal cell cancer syndrome, tuberous sclerosis complex, hereditary papillary renal cell carcinoma, fumarate hydratase deficiency syndrome, BAP1 tumor predisposition syndrome, and other uncommon hereditary cancer syndromes. These conditions are characterized by distinct genetic mutations and related extra-renal symptoms. The majority of renal cell carcinoma predispositions stem from loss-of-function mutations in tumor suppressor genes. These mutations promote malignant advancement through the somatic inactivation of the remaining allele. This review aims to elucidate the main molecular mechanisms underlying the pathophysiology of major syndromes associated with renal cell carcinoma. By providing a comprehensive overview, it aims to facilitate early diagnosis and to highlight the principal therapeutic options available.

[2022 WHO classification of renal cell carcinomas: Focus on papillary renal cell carcinoma]. / Classification OMS 2022 des cancers du rein : focus sur le carcinome rénal papillaire.

Renal cell carcinomas (RCC) represent a group of heterogeneous tumors whose classification has greatly evolved since 1981. The latest update in 2022 classifies all renal cell carcinomas into six categories according to their morphology or the detection of specific molecular alterations. Molecular disassembly of renal cell carcinomas with papillary features has enabled the identification of new entities characterized by a specific molecular alteration, such as Fumarate Hydratase (FH) deficient RCC, TFE3-rearranged RCC or TFEB-altered RCC. This new classification allows for a more accurate diagnosis but requires a thorough knowledge of the genomic alterations to search for with immunohistochemical or molecular biology techniques. According to the new WHO 2022 classification, papillary renal cell carcinoma (PRC) type 1 or type 2 classification is no longer recommended. A classification based on nucleolar ISUP grade must be preferred: low-grade PRC (ISUP 1-2) or high-grade PRC (ISUP 3-4). The other prognostic factors remain the same: the pTNM stage, lymphovascular invasion, and the presence or absence of dedifferentiated areas referring to sarcomatoid or rhabdoid features. Of note, the presence of necrosis is not currently recognized as a poor prognostic element for this type of carcinoma. The diagnosis of high-grade PRC is from now on a diagnosis of exclusion. It can only be sustained after having ruled out TFE3-rearranged RCC, TFEB-altered RCC, and FH-deficient RCC. For clinicians, the diagnosis of PRC implies suggesting an oncogenetic consultation to screen for an associated genetic tumor syndrome regardless of the patient's age.

Network diffusion-based approach for survival prediction and identification of biomarkers using multi-omics data of papillary renal cell carcinoma.

Identification of cancer subtypes based on molecular knowledge is crucial for improving the patient diagnosis, prognosis, and treatment. In this work, we integrated copy number variations (CNVs) and transcriptomic data of Kidney Papillary Renal Cell Carcinoma (KIRP) using a network diffusion strategy to stratify cancers into clinically and biologically relevant subtypes. We constructed GeneNet, a KIRP specific gene expression network from RNA-seq data. The copy number variation data was projected onto GeneNet and propagated on the network for clustering. We identified robust subtypes that are biologically informative and significantly associated with patient survival, tumor stage and clinical subtypes of KIRP. We performed a Singular Value Decomposition (SVD) analysis of KIRP subtypes, which revealed the genes/silent players related to poor survival. A differential gene expression analysis between subtypes showed that genes related to immune, extracellular matrix organization, and genomic instability are upregulated in the poor survival group. Overall, the network-based approach revealed the molecular subtypes of KIRP and captured the relationship between gene expression and CNVs. This framework can be further expanded to integrate other omics data.

ABCC2 brush-border expression predicts outcome in papillary renal cell carcinoma: a multi-institutional study of 254 cases.

AIMS: Papillary renal cell carcinoma (PRCC) histologic subtyping is no longer recommended in the 2022 WHO classification. Currently, WHO/ISUP nucleolar grade is the only accepted prognostic histologic parameter for PRCC. ABCC2, a renal drug transporter, has been shown to significantly predict outcomes in PRCC. In this study we evaluated the prognostic significance of ABCC2 IHC staining patterns in a large, multi-institutional PRCC cohort and assessed the association of these patterns with ABCC2 mRNA expression. METHODS AND RESULTS: We assessed 254 PRCCs for ABCC2 IHC reactivity patterns that were stratified into negative, cytoplasmic, brush-border <50%, and brush-border ≥50%. RNA in situ hybridization (ISH) was used to determine the transcript level of each group. Survival analysis was performed with SPSS and GraphPad software. RNA-ISH showed that the ABCC2 group with any brush-border staining was associated with a significant increase in the transcript level, when compared to the negative/cytoplasmic group (P = 0.034). Both ABCC2 groups with brush-border <50% (P = 0.024) and brush-border ≥50% (P < 0.001) were also associated with worse disease-free survival (DFS) in univariate analysis. Multivariate analysis showed that only ABCC2 IHC brush-border (<50% and ≥50%) reactivity groups (P = 0.037 and P = 0.003, respectively), and high-stage disease (P < 0.001) had a DFS of prognostic significance. In addition, ABCC2 brush-border showed significantly worse DFS in pT1a (P = 0.014), pT1 (P = 0.013), ≤4 cm tumour (P = 0.041) and high stage (P = 0.014) groups, while a similar analysis with high WHO/ISUP grade in these groups was not significant. CONCLUSION: ABCC2 IHC brush-border expression in PRCC correlates with significantly higher gene expression and also independently predicts survival outcomes.

Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging: Diagnostic Pathways and Metabolites for Renal Tumor Entities.

BACKGROUND: Correct tumor subtyping of primary renal tumors is essential for treatment decision in daily routine. Most of the tumors can be classified based on morphology alone. Nevertheless, some diagnoses are difficult, and further investigations are needed for correct tumor subtyping. Besides histochemical investigations, high-mass-resolution matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can detect new diagnostic biomarkers and hence improve the diagnostic. PATIENTS AND METHODS: Formalin-fixed paraffin embedded tissue specimens from clear cell renal cell carcinoma (ccRCC, n = 552), papillary renal cell carcinoma (pRCC, n = 122), chromophobe renal cell carcinoma (chRCC, n = 108), and renal oncocytoma (rO, n = 71) were analyzed by high-mass-resolution MALDI fourier-transform ion cyclotron resonance (FT-ICR) MSI. The SPACiAL pipeline was executed for automated co-registration of histological and molecular features. Pathway enrichment and pathway topology analysis were performed to determine significant differences between RCC subtypes. RESULTS: We discriminated the four histological subtypes (ccRCC, pRCC, chRCC, and rO) and established the subtype-specific pathways and metabolic profiles. rO showed an enrichment of pentose phosphate, taurine and hypotaurine, glycerophospholipid, amino sugar and nucleotide sugar, fructose and mannose, glycine, serine, and threonine pathways. ChRCC is defined by enriched pathways including the amino sugar and nucleotide sugar, fructose and mannose, glycerophospholipid, taurine and hypotaurine, glycine, serine, and threonine pathways. Pyrimidine, amino sugar and nucleotide sugar, glycerophospholipids, and glutathione pathways are enriched in ccRCC. Furthermore, we detected enriched phosphatidylinositol and glycerophospholipid pathways in pRCC. CONCLUSION: In summary, we performed a classification system with a mean accuracy in tumor discrimination of 85.13%. Furthermore, we detected tumor-specific biomarkers for the four most common primary renal tumors by MALDI-MSI. This method is a useful tool in differential diagnosis and biomarker detection.

Prognostic value of IKBIP in papillary renal cell carcinoma.

BACKGROUND: I kappa B kinase interacting protein, a highly conserved gene, has rarely been reported in cancer. According to previous study, IKBIP has only been shown to promote malignant progression of glioma. In other malignant tumors, few reports have examined the function of IKBIP, especially in papillary renal cell carcinoma. Therefore, the molecular profiles and clinical prognostic values of the IKBIP in papillary renal cell carcinoma remain undetermined. METHODS: Several bioinformatic platforms and Immunohistochemistry were used to clarify the expression and prognostic values of IKBIP in Papillary renal cell carcinoma. RESULTS: In this study, GEPIA and TIMER platform were used to identify mRNA expression of IKBIP in papillary renal cell carcinoma. And our results revealed that IKBIP mRNA expression was up-regulated in papillary renal cell carcinoma than in its corresponding normal tissues. In addition, high mRNA expression levels of IKBIP were correlated with age, pathological stage, pathological T stage and pathological N stage. Moreover, High IKBIP mRNA expression was negatively correlated with overall survival (OS) and disease-free survival (DFS) in patients of papillary renal cell carcinoma. Besides, Multivariate analysis indicated that IKBIP mRNA expression was an independent prognostic factor for patients of papillary renal cell carcinoma. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed IKBIP co-expressed genes were enriched in homologous recombination, DNA replication, cell cycle, Mismatch repair, Fanconi anemia pathway, P53 signaling pathway and nucleotide excision repair. And Immunohistochemical profile showed that protein expression of IKBIP was higher in papillary renal cell carcinoma than adjacent normal tissue. CONCLUSIONS: Overall, our findings reveled that IKBIP may act as a novel and potential tumor factor to accelerate papillary renal cell carcinoma progression, meanwhile, IKBIP could serve as a promising target for treating papillary renal cell carcinoma.

Identification of prognostic and therapeutic biomarkers in type 2 papillary renal cell carcinoma.

BACKGROUND: Papillary renal cell carcinoma (PRCC) can be divided into type 1 (PRCC1) and type 2 (PRCC2) and PRCC2 share a more invasive phenotype and worse prognosis. This study aims to identify potential prognostic and therapeutic biomarkers in PRCC2. METHODS: A cohort from The Cancer Genome Atlas and two datasets from Gene Expression Omnibus were examined. Common differentially expressed genes (DEGs) were screened and potential biomarkers were explored by using Kaplan-Meier method and cox regression analysis. Functional enrichment analysis was utilized to evaluate the potential biological functions. Tumor infiltrating immune cells were estimated by CIBERSORT algorithm. Ninety-two PRCC2 samples from Fudan University Shanghai Cancer Center were obtained, and immunostaining was performed to validate prognostic and therapeutic significance of the potential biomarker. RESULTS: PRCC2 has worse overall survival and shares distinct molecular characteristics from PRCC1. There was significant higher expression level of Targeting protein for Xklp2 (TPX2) in PRCC2 compared with normal tissues. Higher expression level of TPX2 was significantly associated with worse overall survival in PRCC2 and kinesin family genes expression were found significantly elevated in high risk PRCC2. Abundance of tumor infiltrating M1 macrophage was significantly higher in PRCC2 and it was also associated with worse overall survival. In the FUSCC cohort, higher TPX2 expression was significantly correlated with worse overall and progression-free survival. Retrospective analysis indicated that mTOR inhibitor (everolimus) had greater efficacy in the high-risk group than in the low-risk group (overall response rate: 28.6% vs. 16.7%) and that everolimus had greater efficacy than sunitinib in the high-risk group (overall response rate: 28.6% vs. 20%). CONCLUSIONS: TPX2 was a prognostic and therapeutic biomarker in PRCC2. Higher abundance of tumor infiltrating M1 macrophage was significantly associated with worse overall survival in PRCC2. mTOR inhibitors may have good efficacy in patients with high-risk PRCC2.

Evaluation of Gas 6 as a Prognostic Marker in Papillary Renal Cell Carcinoma.

INTRODUCTION: Growth arrest-specific protein 6 (Gas 6) is a ligand that plays a role in proliferation and migration of cells. For several tumor entities, high levels of Gas 6 are associated with poorer survival. We examined the prognostic role of Gas 6 in renal cell carcinoma (RCC), especially in papillary RCC (pRCC), which is still unclear. METHODS: The patients' sample collection is a joint collaboration of the PANZAR consortium. Patients' medical history and tumor specimens were collected from n = 240 and n = 128 patients with type 1 and 2 pRCC, respectively. Expression of Gas 6 was determined by immunohistochemistry. RESULTS: In total, Gas 6 staining was evaluable in 180 of 240 type 1 and 110 of 128 type 2 pRCC cases. Kaplan-Meier analysis disclosed no significant difference in 5-year overall survival for all pRCC nor either subtype. Also, Gas+ and Gas- groups did not significantly differ in any tumor or patient characteristics. CONCLUSION: Gas 6 was not found to be an independent prognostic marker in pRCC. Future studies are warranted to determine if Gas 6 plays a role as prognostic marker or therapeutic target in pRCC.

Mesenchymal-Epithelial Transition Kinase Inhibitor Therapy in Patients with Advanced Papillary Renal-Cell Carcinoma: A Systematic Review and Meta-Analysis.

Papillary subtypes of renal-cell carcinoma (pRCC) represent 10-15% of the cases and commonly have MET alterations. This systematic review and single-arm meta-analysis evaluated MET inhibitor therapy (METi) efficacy and safety in adults with confirmed advanced pRCC. The search strategy included PubMed, Web-of-science, Cochrane, and Scopus. We used the DerSimonian/Laird random effect model for all analyses; p-value < 5% was considered significant, and heterogeneity was assessed with I2. Three clinical trials and six cohort studies were included with 504 patients; 31% were MET-driven. Our pooled analysis demonstrated an objective response rate (ORR) in MET-driven, MET-independent, and overall patients of: 36% (95%CI: 10-62), 0% (95%CI: 0-3), and 21% (95%CI: 1-41), respectively. One-year disease control and progression-free survival rates were, respectively, 70% (95%CI: 52-88) and 15% (95%CI: 10-20). Twelve- and twenty-four-month survival rates were, respectively, 43% (95%CI: 23-64) and 10% (95%CI: 0-30). The prevalence of adverse events of any grade and grades 3-5 were 96% (95%CI: 91-100) and 44% (95%CI: 37-50), respectively. We suggest METi has anti-tumor activity and is tolerable in patients with advanced pRCC.

Cuproptosis-Related LncRNA-Based Prediction of the Prognosis and Immunotherapy Response in Papillary Renal Cell Carcinoma.

Cuproptosis, a new cell death pattern, is promising as an intervention target to treat tumors. Abnormal long non-coding RNA (lncRNA) expression is closely associated with the occurrence and development of papillary renal cell carcinoma (pRCC). However, cuproptosis-related lncRNAs (CRLs) remain largely unknown as prognostic markers for pRCC. We aimed to forecast the prognosis of pRCC patients by constructing models according to CRLs and to examine the correlation between the signatures and the inflammatory microenvironment. From the Cancer Genome Atlas (TCGA), RNA sequencing, genomic mutations and clinical data of TCGA-KIRP (Kidney renal papillary cell carcinoma) were analyzed. Randomly selected pRCC patients were allotted to the training and testing sets. To determine the independent prognostic impact of the training characteristic, the least absolute shrinkage and selection operator (LASSO) algorithm was utilized, together with univariate and multivariate Cox regression models. Further validation was performed in the testing and whole cohorts. External datasets were utilized to verify the prognostic value of CRLs as well. The CRLs prognostic features in pRCC were established based on the five CRLs (AC244033.2, LINC00886, AP000866.1, MRPS9-AS1 and CKMT2-AS1). The utility of CRLs was evaluated and validated in training, testing and all sets on the basis of the Kaplan-Meier (KM) survival analysis. The risk score could be a robust prognostic factor to forecast clinical outcomes for pRCC patients by the LASSO algorithm and univariate and multivariate Cox regression. Analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) data demonstrated that differentially expressed genes (DEGs) are primarily important for immune responses and the PI3K-Akt pathway. Arachidonic acid metabolism was enriched in the high-risk set by Gene Set Enrichment Analysis (GSEA). In addition, Tumor Immune Dysfunction and Exclusion (TIDE) analysis suggested that there was a high risk of immune escape in the high-risk cohort. The immune functions of the low- and high-risk sets differed significantly based on immune microenvironment analysis. Finally, four drugs were screened with a higher sensitivity to the high-risk set. Taken together, a novel model according to five CRLs was set up to forecast the prognosis of pRCC patients, which provides a potential strategy to treat pRCC by a combination of cuproptosis and immunotherapy.