Mitochondria-ER contact mediated by MFN2-SERCA2 interaction supports CD8+ T cell metabolic fitness and function in tumors.

Metabolic fitness of T cells is essential for their vitality, which is largely dependent on the behavior of the mitochondria. The nature of mitochondrial behavior in tumor-infiltrating T cells remains poorly understood. In this study, we show that mitofusin-2 (MFN2) expression is positively correlated with the prognosis of multiple cancers. Genetic ablation of Mfn2 in CD8+ T cells dampens mitochondrial metabolism and function and promotes tumor progression. In tumor-infiltrating CD8+ T cells, MFN2 enhances mitochondria-endoplasmic reticulum (ER) contact by interacting with ER-embedded Ca2+-ATPase SERCA2, facilitating the mitochondrial Ca2+ influx required for efficient mitochondrial metabolism. MFN2 stimulates the ER Ca2+ retrieval activity of SERCA2, thereby preventing excessive mitochondrial Ca2+ accumulation and apoptosis. Elevating mitochondria-ER contact by increasing MFN2 in CD8+ T cells improves the efficacy of cancer immunotherapy. Thus, we reveal a tethering-and-buffering mechanism of organelle cross-talk that regulates the metabolic fitness of tumor-infiltrating CD8+ T cells and highlights the therapeutic potential of enhancing MFN2 expression to optimize T cell function.

Multimodal recurrence scoring system for prediction of clear cell renal cell carcinoma outcome: a discovery and validation study.

BACKGROUND: Improved markers for predicting recurrence are needed to stratify patients with localised (stage I-III) renal cell carcinoma after surgery for selection of adjuvant therapy. We developed a novel assay integrating three modalities-clinical, genomic, and histopathological-to improve the predictive accuracy for localised renal cell carcinoma recurrence. METHODS: In this retrospective analysis and validation study, we developed a histopathological whole-slide image (WSI)-based score using deep learning allied to digital scanning of conventional haematoxylin and eosin-stained tumour tissue sections, to predict tumour recurrence in a development dataset of 651 patients with distinctly good or poor disease outcome. The six single nucleotide polymorphism-based score, which was detected in paraffin-embedded tumour tissue samples, and the Leibovich score, which was established using clinicopathological risk factors, were combined with the WSI-based score to construct a multimodal recurrence score in the training dataset of 1125 patients. The multimodal recurrence score was validated in 1625 patients from the independent validation dataset and 418 patients from The Cancer Genome Atlas set. The primary outcome measured was the recurrence-free interval (RFI). FINDINGS: The multimodal recurrence score had significantly higher predictive accuracy than the three single-modal scores and clinicopathological risk factors, and it precisely predicted the RFI of patients in the training and two validation datasets (areas under the curve at 5 years: 0·825-0·876 vs 0·608-0·793; p<0·05). The RFI of patients with low stage or grade is usually better than that of patients with high stage or grade; however, the RFI in the multimodal recurrence score-defined high-risk stage I and II group was shorter than in the low-risk stage III group (hazard ratio [HR] 4·57, 95% CI 2·49-8·40; p<0·0001), and the RFI of the high-risk grade 1 and 2 group was shorter than in the low-risk grade 3 and 4 group (HR 4·58, 3·19-6·59; p<0·0001). INTERPRETATION: Our multimodal recurrence score is a practical and reliable predictor that can add value to the current staging system for predicting localised renal cell carcinoma recurrence after surgery, and this combined approach more precisely informs treatment decisions about adjuvant therapy. FUNDING: National Natural Science Foundation of China, and National Key Research and Development Program of China.

Genome-Wide Profiling Reveals HPV Integration Pattern and Activated Carcinogenic Pathways in Penile Squamous Cell Carcinoma.

Human papillomavirus (HPV) is a significant etiologic driver of penile squamous cell carcinoma (PSCC). The integration pattern of HPV and its carcinogenic mechanism in PSCC remain largely unclear. We retrospectively reviewed 108 PSCC cases who received surgery between 2008 and 2017. Using high-throughput viral integration detection, we identified 35 HPV-integrated PSCCs. Unlike cervical cancer, the HPV E2 oncogene was not prone to involvement in integration. Eleven of the 35 (31.4%) HPV-integrated PSCCs harbored intact HPV E2; these tumors had lower HPV E6 and E7 expression and higher expression of p53 and pRb proteins than those with disrupted E2 did (p < 0.001 and p = 0.024). Integration breakpoints are preferentially distributed in or near host genes, including previously reported hotspots (KLF5, etc.) and newly identified hotspots (CADM2, etc.), which are mainly involved in oncogenic signaling pathways (MAPK, JAK/STAT, etc.). Regarding the phosphorylation levels of JNK, p38 was higher in HPV-positive tumors with MAPK-associated integration than those in HPV-positive tumors with other integration and those in HPV-negative tumors. In vitro, KLF5 knockdown inhibited proliferation and invasion of PSCC cells, while silencing CADM2 promoted migration and invasion. In conclusion, this study enhances our understanding of HPV-induced carcinogenesis in PSCC, which may not only rely on the E6/E7 oncogenes, but mat also affect the expression of critical genes and thus activate oncogenic pathways.

Circular RNA circSNX6 promotes sunitinib resistance in renal cell carcinoma through the miR-1184/GPCPD1/ lysophosphatidic acid axis.

Sunitinib resistance is a major challenge in systemic therapy for renal cell carcinoma (RCC). The role of circular RNAs (circRNAs) in regulating sunitinib resistance of RCC is largely unknown. We established sunitinib-resistant RCC cell lines in vivo. Through RNA-sequencing, we identified circSNX6, whose expression is upregulated in sunitinib-resistant cells compared with their parental cells. High circSNX6 expression was correlated with sunitinib resistance and worse oncologic outcomes in a cohort of 81 RCC patients. In vitro and in vivo experiments confirmed that circSNX6 could promote sunitinib resistance in RCC. circSNX6 acts as a molecular "sponge" to relieve the suppressive effect of microRNA (miR)-1184 on its target gene, glycerophosphocholine phosphodiesterase 1 (GPCPD1), which increases intracellular lysophosphatidic acid (LPA) levels and, ultimately, promotes sunitinib resistance in RCC cells. Our findings demonstrated that the circSNX6/miR-1184/GPCPD1 axis had a critical role in regulation of intracellular LPA levels and sunitinib resistance in RCC; they also provide a novel prognostic indicator and promising therapeutic targets.

Up-regulation of indoleamine 2,3-dioxygenase 1 (IDO1) expression and catalytic activity is associated with immunosuppression and poor prognosis in penile squamous cell carcinoma patients.

BACKGROUND: Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan (Trp) catabolism have been demonstrated to play an important role in tumor immunosuppression. This study examined the expression and catalytic activity of IDO1 in penile squamous cell carcinoma (PSCC) and explored their clinical significance. METHODS: IDO1 expression level, serum concentrations of Trp and kynurenine (Kyn) were examined in 114 PSCC patients by immunohistonchemistry and solid-phase extraction-liquid chromatography-tandem mass spectrometry. The survival was analyzed using Kaplan-Meier method and the log-rank test. Hazard ratio of death was analyzed via univariate and multivariate Cox regression. Immune cell types were defined by principal component analysis. The correlativity was assessed by Pearson's correlation analysis. RESULTS: The expression level of IDO1 in PSCC cells was positively correlated with serum Kyn concentration and Kyn/Trp radio (KTR; both P < 0.001) but negatively correlated with serum Trp concentration (P = 0.001). Additionally, IDO1 up-regulation in cancer cells and the increase of serum KTR were significantly associated with advanced N stage (both P < 0.001) and high pathologic grade (P = 0.008 and 0.032, respectively). High expression level of IDO1 in cancer cells and serum KTR were associated with short disease-specific survival (both P < 0.001). However, besides N stage (hazard radio [HR], 6.926; 95% confidence interval [CI], 2.458-19.068; P < 0.001) and pathologic grade (HR, 2.194; 95% CI, 1.021-4.529; P = 0.038), only serum KTR (HR, 2.780; 95% CI, 1.066-7.215; P = 0.036) was an independent predictor for PSCC prognosis. IDO1 expression was positively correlated with the expression of interferon-γ (IFNγ, P < 0.001) and immunosuppressive markers (programmed cell death protein 1, cytotoxic T-lymphocyte-associated protein 4 and programmed death-ligand 1 and 2; all P < 0.05), and the infiltration of immune cells (including cytotoxic T lymphocytes, regulatory T lymphocytes, tumor-associated macrophages, and myeloid-derived suppressor cells; all P < 0.001) in PSCC tissues. Furthermore, the expression of IDO1 was induced by IFNγ in a dose-dependent manner in PSCC cells. CONCLUSIONS: IFNγ-induced IDO1 plays a crucial role in immunoediting and immunosuppression in PSCC. Additionally, serum KTR, an indicator of IDO1 catabolic activity, can be utilized as an independent prognostic factor for PSCC.

EGFR mono-antibody salvage therapy for locally advanced and distant metastatic penile cancer: Clinical outcomes and genetic analysis.

PURPOSE: There are limited therapeutic options for patients with advanced penile squamous cell carcinoma (PSCC) after chemotherapy failure. Thus, we evaluated the feasibility of salvage treatment using the epidermal growth factor receptor (EGFR) mono-antibody nimotuzumab in chemotherapy-failed PSCC patients and explored potential response or resistance biomarkers. MATERIALS AND METHODS: Six chemotherapy-failed PSCC patients with locally advanced disease or distant metastasis were enrolled consecutively to nimotuzumab treatment. Clinical responses and side effects were evaluated, and genetic characteristics of cancer specimens were analyzed through the next-generation sequencing of hotspot regions in cancer-related genes. RESULTS: Two of 6 patients showed partial responses, one was identified as having stable disease, while the other 3 had disease progression after nimotuzumab therapy. Side effects were all welltolerated. Genetic analysis revealed that TP53, CDKN2A, RB1, SMAD4, FLT3, and PIK3CA were the most frequently mutated genes in PSCC specimens, while altered KRAS, HRAS, EGFR, ERBB2, and FLT3 may be correlated with nimotuzumab resistance. Furthermore, 3 patients that were human papillomavirus-positive each showed clinical response or stable disease. CONCLUSIONS: EGFR mono-antibody may be a potential modality for locally advanced PSCC patients after chemotherapy failure. Further large-scale clinical studies are needed to elucidate the role of human papillomavirus status and critical gene mutations in the clinical response to EGFR-targeted therapy.

Elevated serum LAMC2 is associated with lymph node metastasis and predicts poor prognosis in penile squamous cell carcinoma.

PURPOSE: Molecular biomarkers, especially serologic factors, have been widely applied in cancer diagnosis and patient follow-up. However, there are few valuable prognostic factors in penile squamous cell carcinoma (PSCC). Here, the authors investigated whether laminin gamma 2 (LAMC2) expression, especially serum LAMC2 (sLAMC2) level, was a suitable prognostic factor that could aid in the prediction of survival in PSCC. PATIENTS AND METHODS: This study included 114 PSCC patients. Reverse transcription-quantitative polymerase chain reaction, Western blotting, and immunohistochemistry were performed to detect LAMC2 expression; enzyme-linked immunosorbent assays were used to test sLAMC2 concentration; and a Transwell assay and an in vivo experiment in nude mice were used to test PSCC cell migration, invasion, and metastasis. The chi-squared test was used to analyze the association between LAMC2 level and clinical parameters, the Cox proportional hazards regression model was used to evaluate the hazard ratio for death, and Kaplan-Meier analysis with a log-rank test was used for the survival analysis. RESULTS: LAMC2 was overexpressed in PSCC tissues, and the LAMC2 expression level was higher in metastatic lymph node (LN) tissues than in primary cancer tissues; moreover, the LAMC2 levels in primary cancer tissues and sLAMC2 were higher in patients with LN metastasis than in those without LN metastasis. Upregulated LAMC2 facilitated the migration, invasion, and epithelial-to-mesenchymal transition of PSCC cells in vitro and promoted LN metastasis of PSCC cells in nude mice. Elevated LAMC2 levels were strongly correlated with advanced clinicopathologic parameters, especially LN metastasis, in PSCC patients and predicted shorter disease-specific survival. The predictive value of sLAMC2 is superior to that of C-reactive protein and squamous cell carcinoma antigen previously reported in PSCC patients, and a stratification analysis revealed that the level of sLAMC2 had a higher predictive value for disease-specific survival in early penile cancer (especially at the N0/X stage) than in later-stage penile cancer. CONCLUSION: These findings suggest that sLAMC2 is a potential serologic prognostic marker in PSCC and could aid in risk stratification in early-stage PSCC patients.

Molecular characterization and integrative genomic analysis of a panel of newly established penile cancer cell lines.

Cell line models are essential tools to study the molecular mechanisms underlying tumor initiation and progression. There are limited treatment options for penile squamous cell carcinoma (PSCC), accounting for 1-2% of male tumors in developing countries, and limited progress in preclinical research in PSCC due to lacking available models with identified genomic characteristics. Here, biological and molecular characteristics and whole-genomic alterations were analyzed in a panel of PSCC cell lines newly established in our laboratory. These cell lines were all human papillomavirus (HPV)-negative, epithelial-like, immortalized, and tumorigenic in nude mice, whereas they displayed different proliferation, migration and invasion capacities in vitro, and tumorigenic ability in nude mice. They were all cisplatin sensitive, anti-EGFR therapy resistant, and androgen irresponsive. Whole-genomic sequecing analysis revealed that transition mutations (C:G>T:A and T:A>C:G) were the most common substitution types in these cell lines, whereas ERCC5, TP53, PTH1, CLTCL1, NOTCH2, MAP2K3, CDK11A/B, USP6, ADCH5, BCLAF1, CDKN2A, FANCD2, HRAS, and NOTCH1 were the most frequently altered genes. Amplifications of MYC, PLAG1, NCOA2, RUNX1T1, COX6C, and EGFR and losses of FBXW7, TET2, XPC, and FANCE were frequently observed in cell lines. The exomic variations between cell lines and their corresponding cancer tissues were highly consistent. Genetic variations were mainly involved in the MAPK, Jak-STAT, TGF-beta, Notch, and apoptosis signaling pathways. Conclusively, these panel of PSCC cell lines established in our laboratory harbor some common or specific biological characteristics and genomic variations, and they may serve as optimal models to investigate the molecular mechanisms underlying the progression, metastasis, relapses, and treatment resistance of PSCC and to develop effective treatment strategy.