Posttranslational modifications (PTMs) of tubulin specify microtubules for specialized cellular functions and comprise what is termed a “tubulin code.” PTMs of histones comprise an analogous “histone ...code,” although the “readers, writers, and erasers” of the cytoskeleton and epigenome have heretofore been distinct. We show that methylation is a PTM of dynamic microtubules and that the histone methyltransferase SET-domain-containing 2 (SETD2), which is responsible for H3 lysine 36 trimethylation (H3K36me3) of histones, also methylates α-tubulin at lysine 40, the same lysine that is marked by acetylation on microtubules. Methylation of microtubules occurs during mitosis and cytokinesis and can be ablated by SETD2 deletion, which causes mitotic spindle and cytokinesis defects, micronuclei, and polyploidy. These data now identify SETD2 as a dual-function methyltransferase for both chromatin and the cytoskeleton and show a requirement for methylation in maintenance of genomic stability and the integrity of both the tubulin and histone codes.
Display omitted
•Dynamic microtubules are methylated during mitosis and cytokinesis•SETD2 methylates α-tubulin at lysine 40, the same lysine that is acetylated•Loss of microtubule methylation causes genomic instability
Tubulin and histones share a methyltransferase, suggesting a new basis for known tumorigenic mutations in the enzyme.
Despite systemic therapy and cystectomy, bladder cancer is characterized by a high recurrence rate. Serum glycomics represents a promising source of prognostic markers for monitoring patients. Our ...approach, which we refer to as "glycan node analysis", constitutes the first example of molecularly "bottom-up" glycomics. It is based on a global glycan methylation analysis procedure that is applied to whole blood plasma/serum. The approach detects and quantifies partially methylated alditol acetates arising from unique glycan features such as α2-6 sialylation, β1-4 branching, and core fucosylation that have been pooled together from across all intact glycans within a sample into a single GC-MS chromatographic peak. We applied this method to 122 plasma samples from former and current bladder cancer patients (n = 72 former cancer patients with currently no evidence of disease (NED); n = 38 non-muscle invasive bladder cancer (NMIBC) patients; and n = 12 muscle invasive bladder cancer (MIBC) patients) along with plasma from 30 certifiably healthy living kidney donors. Markers for α2-6 sialylation, β1-4 branching, β1-6 branching, and outer-arm fucosylation were able to separate current and former (NED) cases from certifiably healthy controls (ROC curve c-statistics ~ 0.80); but NED, NMIBC, and MIBC were not distinguished from one another. Based on the unexpectedly high levels of these glycan nodes in the NED patients, we hypothesized that recurrence of this disease could be predicted by some of the elevated glycan features. Indeed, α2-6 sialylation and β1-6 branching were able to predict recurrence from the NED state using a Cox proportional hazards regression model adjusted for age, gender, and time from cancer. The levels of these two glycan features were correlated to C-reactive protein concentration, an inflammation marker and known prognostic indicator for bladder cancer, further strengthening the link between inflammation and abnormal plasma protein glycosylation.
Renal Cell Carcinoma (RCC) is a fatal urological cancer, with one third of patients diagnosed with metastasis, resulting in a 5-year survival of only 12%. Recent advancements in therapies have ...increased survival in mRCC, but lack efficacy in subtypes, due to treatment resistance and toxic side effects. Currently, white blood cells, hemoglobin, and platelets are limitedly used as blood based biomarkers to help determine RCC prognosis. Cancer associated macrophage-like cells (CAMLs) are a potential mRCC biomarker which have been identified in peripheral blood of patients with malignant tumors and have been shown to predict poor clinical patient outcomes based on their number and size. In this study, blood samples from 40 RCC patients were obtained to evaluate the clinical utility of CAMLs. CAML changes were monitored during treatment regimens to evaluate their ability to predict treatment efficacy. It was observed that patients with smaller CAMLs had better progression free survival (HR = 2.84, 95% CI 1.22-6.60, p = 0.0273) and overall survival (HR = 3.95, 95% CI 1.45-10.78, p = 0.0154) versus patients with larger CAMLs. These findings suggest that CAMLs can be used as a diagnostic, prognostic, and predictive biomarker for patients with RCC which may help improve management of advanced RCC.
Identifying the most effective first-line treatment for metastatic renal cell carcinoma (mRCC) is challenging as rapidly evolving data quickly outdate the existing body of evidence, and current ...approaches to presenting the evidence in user-friendly formats are fraught with limitations.
To maintain living evidence for contemporary first-line treatment for previously untreated mRCC.
We have created a living, interactive systematic review (LISR) and network meta-analysis for first-line treatment of mRCC using data from randomized controlled trials comparing contemporary treatment options with single-agent tyrosine kinase inhibitors. We applied an advanced programming and artificial intelligence–assisted framework for evidence synthesis to create a living search strategy, facilitate screening and data extraction using a graphical user interface, automate the frequentist network meta-analysis, and display results in an interactive manner.
As of October 22, 2020, the LISR includes data from 14 clinical trials. Baseline characteristics are summarized in an interactive table. The cabozantinib + nivolumab combination (CaboNivo) is ranked the highest for the overall response rate, progression-free survival, and overall survival, whereas ipilimumab + nivolumab (NivoIpi) is ranked the highest for achieving a complete response (CR). NivoIpi, and atezolizumab + bevacizumab (AteBev) were ranked highest (lowest toxicity) and CaboNivo ranked lowest for treatment-related adverse events (AEs). Network meta-analysis results are summarized as interactive tables and plots, GRADE summary-of-findings tables, and evidence maps.
This innovative living and interactive review provides the best current evidence on the comparative effectiveness of multiple treatment options for patients with untreated mRCC. Trial-level comparisons suggest that CaboNivo is likely to cause more AEs but is ranked best for all efficacy outcomes, except NivoIpi offers the best chance of CR. Pembrolizumab + axitinib and NivoIpi are acceptable alternatives, except NivoIpi may not be preferred for patients with favorable risk. Although network meta-analysis provides rankings with statistical adjustments, there are inherent biases in cross-trial comparisons with sparse direct evidence that does not replace randomized comparisons.
It is challenging to decide the best option among the several treatment combinations of immunotherapy and targeted treatments for newly diagnosed metastatic kidney cancer. We have created interactive evidence summaries of multiple treatment options that present the benefits and harms and evidence certainty for patient-important outcomes. This evidence is updated as soon as new studies are published.
This innovative living and interactive systematic review provides the best current evidence on the comparative effectiveness of multiple treatment options for patients with untreated metastatic renal cell carcinoma. The cabozantinib + nivolumab combination is likely to cause more adverse events but is ranked best for all efficacy outcomes, except for ipilimumab in combination with nivolumab (NivoIpi), which offers the best chance of a complete response. Pembrolizumab-axitinib and NivoIpi are acceptable alternatives, except NivoIpi may not be preferred for patients with favorable risk.
More than 90% of chondroblastomas contain a heterozygous mutation replacing lysine-36 with methionine-36 (K36M) in the histone H3 variant H3.3. Here we show that H3K36 methylation is reduced globally ...in human chondroblastomas and in chondrocytes harboring the same genetic mutation, due to inhibition of at least two H3K36 methyltransferases, MMSET and SETD2, by the H3.3K36M mutant proteins. Genes with altered expression as well as H3K36 di- and trimethylation in H3.3K36M cells are enriched in cancer pathways. In addition, H3.3K36M chondrocytes exhibit several hallmarks of cancer cells, including increased ability to form colonies, resistance to apoptosis, and defects in differentiation. Thus, H3.3K36M proteins reprogram the H3K36 methylation landscape and contribute to tumorigenesis, in part through altering the expression of cancer-associated genes.
Tumor tissues are chronically exposed to hypoxia owing to aberrant vascularity. Lipid droplet (LD) accumulation is a hallmark of hypoxic cancer cells, yet how LDs form and function during hypoxia ...remains poorly understood. Herein, we report that in various cancer cells upon oxygen deprivation, HIF-1 activation down-modulates LD catabolism mediated by adipose triglyceride lipase (ATGL), the key enzyme for intracellular lipolysis. Proteomics and functional analyses identified hypoxia-inducible gene 2 (HIG2), a HIF-1 target, as a new inhibitor of ATGL. Knockout of HIG2 enhanced LD breakdown and fatty acid (FA) oxidation, leading to increased ROS production and apoptosis in hypoxic cancer cells as well as impaired growth of tumor xenografts. All of these effects were reversed by co-ablation of ATGL. Thus, by inhibiting ATGL, HIG2 acts downstream of HIF-1 to sequester FAs in LDs away from the mitochondrial pathways for oxidation and ROS generation, thereby sustaining cancer cell survival in hypoxia.
Renal-cell carcinoma (RCC) is one of the common malignancies in the United States. RCC incidence and mortality have been changing for many reasons. We performed a thorough investigation of incidence ...and mortality trends of RCC in the United States using the cell Surveillance, Epidemiology, and End Results (SEER) database.
The 13 SEER registries were accessed for RCC cases diagnosed between 1992 and 2015. Incidence and mortality were calculated by demographic and tumor characteristics. We calculated annual percentage changes of these rates. Rates were expressed as 100,000 person-years.
A total of 104,584 RCC cases were reviewed, with 47,561 deaths. The overall incidence was 11.281 per 100,000 person-years. Incidence increased by 2.421% per year (95% confidence interval, 2.096, 2.747; P < .001) but later became stable since 2008. However, the incidence of clear-cell subtype continued to increase (1.449%; 95% confidence interval, 0.216, 2.697; P = .024). RCC overall mortality rates have been declining since 2001. However, mortality associated with distant RCC only started to decrease in 2012, with an annual percentage change of 18.270% (95% confidence interval, −28.775, −6.215; P = .006).
Despite an overall increase in the incidence of RCC, there has been a recent plateau in RCC incidence rates with a significant decrease in mortality.
Renal-cell carcinoma (RCC) incidence and mortality have been changing for many reasons. We used the Surveillance, Epidemiology, and End Results database to review 104,584 RCC cases with 47,561 deaths diagnosed between 1992 and 2015. Despite an overall increase in the incidence of RCC, there has been a recent plateau in RCC incidence rates with a significant decrease in mortality.
Methylthioadenosine phosphorylase, an essential enzyme for the adenine salvage pathway, is often deficient (MTAP
) in tumors with 9p21 loss and hypothetically renders tumors susceptible to synthetic ...lethality by antifolates targeting de novo purine synthesis. Here we report our single arm phase II trial (NCT02693717) that assesses pemetrexed in MTAP
urothelial carcinoma (UC) with the primary endpoint of overall response rate (ORR). Three of 7 enrolled MTAP
patients show response to pemetrexed (ORR 43%). Furthermore, a historic cohort shows 4 of 4 MTAP
patients respond to pemetrexed as compared to 1 of 10 MTAP-proficient patients. In vitro and in vivo preclinical data using UC cell lines demonstrate increased sensitivity to pemetrexed by inducing DNA damage, and distorting nucleotide pools. In addition, MTAP-knockdown increases sensitivity to pemetrexed. Furthermore, in a lung adenocarcinoma retrospective cohort (N = 72) from the published BATTLE2 clinical trial (NCT01248247), MTAP
associates with an improved response rate to pemetrexed. Our data demonstrate a synthetic lethal interaction between MTAP
and de novo purine inhibition, which represents a promising therapeutic strategy for larger prospective trials.
The interaction of programmed death-1 ligand (PD-L1) with its receptor (PD-1) on T cells inactivates antitumor immune responses. PD-L1 expression has been associated with poor outcomes in renal cell ...carcinoma (RCC) but has not been investigated in advanced RCC patients receiving VEGF-targeted therapy.
Formalin-fixed paraffin-embedded specimens were collected at baseline from patients in the COMPARZ trial. Tumor cell PD-L1 expression by IHC was evaluated using H-score (HS). Dual PD-L1/CD68 staining was used to differentiate PD-L1 tumor expression from tumor-associated macrophages. Intratumor CD8-positive T cells were quantified morphometrically. Associations between biomarkers and survival were investigated using the log-rank test.
HS data were available from 453 of 1,110 patients. Sixty-four percent of patients had negative PD-L1 expression (HS = 0). Patients with HS > 55 (n = 59, 13%) had significantly shorter overall survival (OS) than those with HS ≤ 55 in both pazopanib and sunitinib arms (median 15.1 vs. 35.6 and 15.3 vs. 27.8 months, respectively, P = 0.03). In both arms, median OS was shortest in patients with HS > 55 and intratumor CD8-positive T-cell counts > 300 (9.6 and 11.9 months with pazopanib and sunitinib, respectively). Median OS in patients with HS ≤ 55 and CD8-positive T-cell counts ≤ 300 was 36.8 and 28.0 months with pazopanib and sunitinib, respectively. Progression-free survival results were similar to OS results.
Increased tumor cell PD-L1, or PD-L1 plus tumor CD8-positive T-cell counts, were associated with shorter survival in patients with metastatic RCC receiving VEGF-targeted agents. These findings may have implications for future design of randomized clinical trials in advanced RCC.
Purpose In clear cell renal cell carcinoma BAP1 and PBRM1 are 2 of the most commonly mutated genes (10% to 15% and 40% to 50%, respectively). We sought to determine the prognostic significance of ...PBRM1 and BAP1 expression in clear cell renal cell carcinoma. Materials and Methods We used immunohistochemistry to assess PBRM1 protein expression in 1,479 primary clear cell renal cell carcinoma tumors that were previously stained for BAP1. A centralized pathologist reviewed all cases and categorized tumors as positive or deficient for PBRM1 and BAP1. Kaplan-Meier and Cox regression models were used to evaluate association of PBRM1 and BAP1 expression with the risk of death from renal cell carcinoma and the risk of metastasis after adjustment for age and the Mayo Clinic SSIGN (stage, size, grade and necrosis) score. Results PBRM1 and BAP1 expression was PBRM1+ BAP1+ in 40.1% of tumors, PBRM1– BAP1+ in 48.6%, PBRM1+ BAP1– in 8.7% and PBRM1– BAP1– in 1.8%. The incidence of PBRM1 and BAP1 loss in the same tumor was significantly lower than expected (actual 1.8% vs expected 5.3%, p <0.0001). Compared to patients with PBRM1+ BAP1+ tumors those with PBRM1– BAP1+ lesions were more likely to die of renal cell carcinoma (HR 1.39, p = 0.035), followed by those with PBRM1+ BAP1– and PBRM1– BAP1– tumors (HR 3.25 and 5.2, respectively, each p <0.001). PBRM1 and BAP1 expression did not add independent prognostic information to the SSIGN score. Conclusions PBRM1 and BAP1 expression identified 4 clinical subgroups of patients with clear cell renal cell carcinoma who had divergent clinical outcomes. The clinical value of these biomarkers will be fully realized when therapies targeting pathways downstream of PBRM1 and BAP1 are developed.
PDF
