Exploration of the Tunability of BRD4 Degradation by DCAF16 Trans-labelling Covalent Glues

Small molecules that can induce protein degradation by inducing proximity between a desired target and an E3 ligase have the potential to greatly expand the number of proteins that can be manipulated pharmacologically. Current strategies for targeted protein degradation are mostly limited in their target scope to proteins with preexisting ligands. Alternate modalities such as molecular glues, as exemplified by the glutarimide class of ligands for the CUL4CRBN ligase, have been mostly discovered serendipitously. We recently reported a trans-labelling covalent glue mechanism which we named 'Template-assisted covalent modification', where an electrophile decorated small molecule binder of BRD4 was effectively delivered to a cysteine residue on an E3 ligase DCAF16 as a consequence of a BRD4-DCAF16 protein-protein interaction. Herein, we report our medicinal chemistry efforts to evaluate how various electrophilic modifications to the BRD4 binder, JQ1, affect DCAF16 trans-labeling and subsequent BRD4 degradation efficiency. We discovered a decent correlation between the ability of the electrophilic small molecule to induce ternary complex formation between BRD4 and DCAF16 with its ability to induce BRD4 degradation. Moreover, we show that a more solvent-exposed warhead presentation is optimal for DCAF16 recruitment and subsequent BRD4 degradation. Unlike the sensitivity of CUL4CRBN glue degraders to chemical modifications, the diversity of covalent attachments in this class of BRD4 glue degraders suggests a high tolerance and tunability for the BRD4-DCAF16 interaction. This offers a potential new avenue for a rational design of covalent glue degraders by introducing covalent warheads to known binders.

Integration of Multiparameter MRI into Conventional Pretreatment Risk Factors to Predict Adverse Features after Radical Prostatectomy

PURPOSE/OBJECTIVE(S)

The purpose of this study was to Integration of Multiparameter MRI into conventional pretreatment risk factors to develop nomogram for the prediction of adverse features (i.e., positive margin (PM) or extra-prostatic extension (EPE)) indicated for postoperative radiotherapy in patients with prostate cancer.

MATERIALS/METHODS

We analyzed 203 histologically proven prostate cancer patients underwent preoperative 3T multiparametric MRI including high b value (0, 1500 s/mm2) diffusion-weighted imaging between 2019 and 2022 at our hospital. Patients with a history of neoadjuvant hormonal therapy, or patients whose surgeon's experience was ≤3 years were excluded. Age, surgical technique, serum PSA level, PSA density, clinical T stage, and biopsy Gleason score were clinical predictors. MRI parameters include prostate volume, tumor size, ECE score, seminal vesicle invasion score, tumor location (apex, peripheral region, or bladder neck), apparent diffusion coefficient (ADC), tumor contact length (TCL), PI-RADS score. Predictors were used in nomograms developed from multivariable logistic regression analysis to estimate the probability of positive margin (PM) or extra-prostatic extension (EPE) after RP. The nomogram's predictive accuracy and discriminative ability were determined by the concordance index with calibration and receiver operating characteristic (ROC) curves.

RESULTS

(1) Patient characters: Table 1 lists the MRI characteristics of the patients. Median PSA level is 17.6ng/ml. All patients received extra-fascial resection. 44% of the patients underwent robotic surgery. 24% of the patients had positive margins. In 226 patients who was clinically confined to the prostate, 100 (44%) had a postoperative pathological upgrade of pT3a or above. 46 (29%) of the 158 patients with biopsy grade group (GG)1 was confirmed GG3-5 after RP.

CONCLUSION

Using mpMRI parameters and clinicopathological information, we produced nomograms that may accurately predict adverse Features that are indications for postoperative radiotherapy after RP, which may help individualize treatment decision-making.

Safety and Efficacy of Radiotherapy Combined with Chemotherapy for Recurrent Metastatic Renal Pelvic and Ureteral Carcinoma

PURPOSE/OBJECTIVE(S)

To retrospectively investigate the safety and efficacy of radiotherapy combined with systemic chemotherapy for recurrent metastatic renal pelvic and ureteral carcinoma.

MATERIALS/METHODS

A total of 109 patients were enrolled in this study, including 44 patients in the Radio-chemotherapy group and 65 patients in the Chemotherapy group. Propensity score matching (PSM) was used to balance the clinical baseline characteristics of the two groups by 1:1 matching. Kaplan-Meier method was used to calculate progression-free survival (PFS) and overall survival (OS) before and after matching. Prognostic factors were analyzed by Cox proportional risk model. Treatment-related adverse events were graded according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0.

RESULTS

The median follow-up time was 14.5 months. Multivariate analysis showed that radiotherapy was a good independent prognostic factor for OS in patients with recurrent metastatic renal pelvic and ureteral carcinoma (HR: 0.327, 95% CI: 0.157∼0.680, P = 0.003). After matching, there were 40 patients in the Radio-chemotherapy group and 40 patients in the Chemotherapy group, and the median PFS and median OS in the Radio-chemotherapy group were better than those in the Chemotherapy group (PFS: 10.4 months vs. 6.7 months, P = 0.035; OS: 43.5 months vs. 18.8 months, P<0.001). The 1-year OS and 2-year OS of the Radio-chemotherapy group were higher than those of the Chemotherapy group (1-year OS: 88.1% vs. 70.4%; 2-year OS: 81.1% vs. 39.3%). In addition, in the Radio-chemotherapy group, patients treated with radiotherapy before first-line chemotherapy failure had longer PFS than those treated with radiotherapy after chemotherapy failure (median PFS: 15.7 months vs. 6 months, P = 0.003). There was no significant difference in the incidence of grade 3∼4 toxicities between the Radio-chemotherapy group and the Chemotherapy group (52.3% vs. 50.8%, P = 0.878).

CONCLUSION

For patients with advanced renal pelvic and ureteral carcinoma, adding radiotherapy on the basis of systemic chemotherapy is well tolerable and expected to bring long-term survival benefits to patients, and the benefits of early interventional radiotherapy may be more obvious.

Effect of Adjuvant Chemotherapy in Highly Malignant Non-Metastatic Prostate Cancer: An Interim Analysis of Non-Randomized Comparative Trials

PURPOSE/OBJECTIVE(S)

Gleason grade group 5 (GG5) prostate cancers is aggressive with high metastatic rates and is not sensitive to androgen deprivation therapy (ADT). Even the presence of a limited (tertiary) Gleason pattern 5 component may have high aggressive biological behavior. This study aims to prospectively evaluate whether a non-androgen receptor pathway therapy - adjuvant chemotherapy could improve clinical outcomes among non-metastatic prostate cancer with the above highly malignant characters.

MATERIALS/METHODS

This prospective non-randomized clinical trial included non-metastatic prostate cancer patients with pathologically proven Gleason score of 9-10 or tertiary Gleason pattern 5. Each subject was allowed to decide whether to receive four to six cycles chemotherapy of docetaxel after receiving a standard treatment (i.e., radical surgery ± radiotherapy or radical radiotherapy combined with long-term ADT). The primary endpoint was event-free survival (EFS). Event was defined as any of biochemical failure or imaging failure, or change of systemic therapy due to PSA arises, or death. The secondary end points were distant metastasis-free survival (MFS), overall survival (OS), and treatment-related adverse events.

RESULTS

A total of 188 consecutive patients were enrolled from November 2019 to November 2022. Median prostate-specific antigen was 26.6 ng/ml. 52% had T3b to T4 disease, 27% had N1 disease. 140 patients received standard therapy only, and 48 patients received adjuvant chemotherapy after radical therapy. The median follow-up time was 18.4 (3.0-36.7) months. The estimated 36-month EFS of the chemotherapy group and the control group were 94.7% vs. 72.8% (p = 0.044). There were 1 event who added novel endocrine therapy in the chemotherapy group, and 21 events in the control group, including 6 cases of biochemical recurrence and 9 cases of lymph node and distant metastasis, 4 cases that changed systemic therapy and 2 cases died. The MFS of the two groups at 36 months were 100% and 90.7%, respectively (P = 0.143). After the 1:1 propensity score match, the EFS and MFS of the two groups were 94.7% and 80.8% (P = 0.069), and 100% and 93.1% (P = 0.132), respectively. The urinary toxicity of grade 2 and 3 in the chemotherapy group and the control group were 4.2% and 7.1% (P = 0.134) while the grade 2 rectal toxicity were 5.0% and 10.4% (P = 0.317), respectively. No grade 4 toxicity occurred. Considering the chemotherapy-related side effects, grade 3 or above toxicity were leukopenia (41.7%), alopecia (27.1%), thrombocytopenia (2.1%) and edema (2.1%).

CONCLUSION

Results of this interim analysis shows that the addition of adjuvant chemotherapy after standard radical therapy tends to improve the overall recurrence and metastasis free survival of patients with highly malignant prostate cancer, and the adverse effects are tolerable, which should be confirmed by long-term follow-up results.

Outcomes of Targeted Therapy Plus Immunotherapy and High-Dose Stereotactic Ablative Body Radiotherapy (SABR) for Metastatic Renal Cell Cancer Patients

PURPOSE/OBJECTIVE(S)

Stereotactic ablative body radiotherapy (SABR) is one of the treatment options for metastatic renal cell carcinoma (mRCC) but is limited by a lack of data to evaluate targeted therapy plus immunotherapy concurrently with high-dose SABR to multiple sites. We evaluated the safety and disease control for mRCC patients who concurrently received the above tri-modality treatment.

MATERIALS/METHODS

Patients were treated with SABR (40-70 Gy/5-10 fractions) for small lesions or partial-SABR (tumor center boosted with 6-8 Gy/3-5 fractions with 50-60 Gy/20-25 fractions to the whole tumor volume) for bulky tumors or tumors adjacent to critical organs. When SABR/partial-SABR was not feasible, a moderate fractionated radiotherapy plan, usually 60Gy/20 fractions were applied. of Targeted therapy plus immunotherapy (PD-1 inhibitor) was not interrupted during or after radiotherapy (RT). Adverse events (AEs) were evaluated. Disease control rate (DCR), objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) were calculated. The PFS1 was defined as the first progression since the start of RT. The PFS2 was defined as the second progression after the second RT course, if new metastases occurred after first RT were all re-irradiated, and the systemic therapy was not changed. The Kaplan-Meier method was used for time-to-event endpoints.

RESULTS

A total of 51 patients, with a median age of 57 yr, were enrolled. The median follow-up was 12 months. There were 75% of patients with intermediate-risk and 18% with favorable-risk disease. 61% of the patients were oligometastatic. 71% had clear cell renal cancer. There were 241 metastases while 161 (67%) were irradiated. 80% of the lesions received SABRP/partial SABR. 1 patient with 14 lesions irradiated received proton therapy. All the surviving patients are continuing using targeted therapy while 81% patients complete at least 1-year PD-1 therapy. 10 patients (20%) had grade 3 drug-related AEs: pneumonitis (n = 2), elevated alanine transaminase (n = 4), myositis (n = 1), hand-foot syndrome myositis (n = 1), enteritis (n = 1), fatigue (n = 1). There were 1 grade 4 AEs of upper gastrointestinal bleeding. No grade 3-5 RT-related AEs was found. ORR and DCR for irradiated lesion were 51% and 98%. Median OS and PFS2 was not reached. Median PFS1 was 14(6-22) months. Estimated 1- and 2-yr OS, PFS1 and PFS2 were 90% and 90%, 56% and 38%, 74% and 51% respectively. Univariate analysis showed that an PFS1 benefit was found in patients who received radiation before systemic therapy failure (p = 0.038).

CONCLUSION

We investigated the high-dose RT in combination of concurrent targeted and immunotherapy in patients with metastatic RCC. We found that this treatment regimen was well tolerated, with good cancer control. Early use of high-dose RT to multi-lesions may improve PFS. Partial-SABR for bulky lesions close to critical organs could be safely and effectively applied under certain circumstances. These encouraging findings warrant further investigation.

HAPSTR1 localizes HUWE1 to the nucleus to limit stress signaling pathways

HUWE1 is a large, enigmatic HECT-domain ubiquitin ligase implicated in the regulation of diverse pathways, including DNA repair, apoptosis, and differentiation. How HUWE1 engages its structurally diverse substrates and how HUWE1 activity is regulated are unknown. Using unbiased quantitative proteomics, we find that HUWE1 targets substrates in a largely cell-type-specific manner. However, we identify C16orf72/HAPSTR1 as a robust HUWE1 substrate in multiple cell lines. Previously established physical and genetic interactions between HUWE1 and HAPSTR1 suggest that HAPSTR1 positively regulates HUWE1 function. Here, we show that HAPSTR1 is required for HUWE1 nuclear localization and nuclear substrate targeting. Nuclear HUWE1 is required for both cell proliferation and modulation of stress signaling pathways, including p53 and nuclear factor κB (NF-κB)-mediated signaling. Combined, our results define a role for HAPSTR1 in gating critical nuclear HUWE1 functions.

Template-assisted covalent modification of DCAF16 underlies activity of BRD4 molecular glue degraders

Small molecules that induce protein-protein interactions to exert proximity-driven pharmacology such as targeted protein degradation are a powerful class of therapeutics1-3. Molecular glues are of particular interest given their favorable size and chemical properties and represent the only clinically approved degrader drugs4-6. The discovery and development of molecular glues for novel targets, however, remains challenging. Covalent strategies could in principle facilitate molecular glue discovery by stabilizing the neo-protein interfaces. Here, we present structural and mechanistic studies that define a trans-labeling covalent molecular glue mechanism, which we term "template-assisted covalent modification". We found that a novel series of BRD4 molecular glue degraders act by recruiting the CUL4DCAF16 ligase to the second bromodomain of BRD4 (BRD4BD2). BRD4BD2, in complex with DCAF16, serves as a structural template to facilitate covalent modification of DCAF16, which stabilizes the BRD4-degrader-DCAF16 ternary complex formation and facilitates BRD4 degradation. A 2.2 Å cryo-electron microscopy structure of the ternary complex demonstrates that DCAF16 and BRD4BD2 have pre-existing structural complementarity which optimally orients the reactive moiety of the degrader for DCAF16Cys58 covalent modification. Systematic mutagenesis of both DCAF16 and BRD4BD2 revealed that the loop conformation around BRD4His437, rather than specific side chains, is critical for stable interaction with DCAF16 and BD2 selectivity. Together our work establishes "template-assisted covalent modification" as a mechanism for covalent molecular glues, which opens a new path to proximity driven pharmacology.

Solenoid architecture of HUWE1 contributes to ligase activity and substrate recognition

HECT ubiquitin ligases play essential roles in metazoan development and physiology. The HECT ligase HUWE1 is central to the cellular stress response by mediating degradation of key death or survival factors, including Mcl1, p53, DDIT4, and Myc. Although mutations in HUWE1 and related HECT ligases are widely implicated in human disease, our molecular understanding remains limited. Here we present a comprehensive investigation of full-length HUWE1, deepening our understanding of this class of enzymes. The N-terminal ~3,900 amino acids of HUWE1 are indispensable for proper ligase function, and our cryo-EM structures of HUWE1 offer a complete molecular picture of this large HECT ubiquitin ligase. HUWE1 forms an alpha solenoid-shaped assembly with a central pore decorated with protein interaction modules. Structures of HUWE1 variants linked to neurodevelopmental disorders as well as of HUWE1 bound to a model substrate link the functions of this essential enzyme to its three-dimensional organization.

Hunkeler et al. present the cryo-EM structure of HUWE1, a large HECT E3 ligase that forms a modular ring-shaped assembly with flexibly attached accessory domains. The influence of mutations associated with intellectual disabilities on HUWE1 activity and substrate recognition by HUWE1 is dissected biochemically and structurally.

Development of Halo Nevi in a Lung Cancer Patient: A Novel Immune-Related Cutaneous Event from Atezolizumab

Immunotherapy-induced vitiligo is an immune-related adverse event (irAE) observed in metastatic melanoma patients treated with immune checkpoint inhibitors that target the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death-1 (PD-1) pathways. To date, the development of leukoderma, poliosis, and halo nevi during immunotherapy has largely been reported in metastatic melanoma patients. We report a case of immunotherapy-induced leukoderma presenting as halo nevi in a patient with non-small cell lung cancer (NSCLC) treated with atezolizumab, a programmed cell death ligand (PD-L1) antibody. Immunotherapy-induced vitiligo in metastatic melanoma patients may be associated with improved survival, but it remains to be determined whether its occurrence in non-melanoma cancers has the same prognostic significance. <p><em>J Drugs Dermatol. 2017;16(10):1047-1049.</em></p>.

Melanoma expression of matrix metalloproteinase-23 is associated with blunted tumor immunity and poor responses to immunotherapy

BACKGROUND

Matrix metalloproteinase-23 (MMP-23) can block the voltage-gated potassium channel Kv1.3, whose function is important for sustained Ca(2+) signaling during T cell activation. MMP-23 may also alter T cell activity and phenotype through cleavage of proteins affecting cytokine and chemokine signaling. We therefore tested the hypothesis that MMP-23 can negatively regulate the anti-tumor T cell response in human melanoma.

METHODS

We characterized MMP-23 expression in primary melanoma patients who received adjuvant immunotherapy. We examined the association of MMP-23 with the anti-tumor immune response - as assessed by the prevalence of tumor-infiltrating lymphocytes and Foxp3(+) regulatory T cells. Further, we examined the association between MMP-23 expression and response to immunotherapy. Considering also an in trans mechanism, we examined the association of melanoma MMP-23 and melanoma Kv1.3 expression.

RESULTS

Our data revealed an inverse association between primary melanoma MMP-23 expression and the anti-tumor T cell response, as demonstrated by decreased tumor-infiltrating lymphocytes (TIL) (P = 0.05), in particular brisk TILs (P = 0.04), and a trend towards an increased proportion of immunosuppressive Foxp3(+) regulatory T cells (P = 0.07). High melanoma MMP-23 expression is also associated with recurrence in patients treated with immune biologics (P = 0.037) but not in those treated with vaccines (P = 0.64). Further, high melanoma MMP-23 expression is associated with shorter periods of progression-free survival for patients receiving immune biologics (P = 0.025). On the other hand, there is no relationship between melanoma MMP-23 and melanoma Kv1.3 expression (P = 0.27).

CONCLUSIONS

Our data support a role for MMP-23 as a potential immunosuppressive target in melanoma, as well as a possible biomarker for informing melanoma immunotherapies.

Growth performance, meat quality and Fatty Acid metabolism response of growing meat rabbits to dietary linoleic Acid

An experiment was conducted to determine the effects of different amounts of dietary linoleic acid (LA) on growth performance, serum biochemical traits, meat quality, fatty acids composition of muscle and liver, acetyl-CoA carboxylase (ACC) and carnitine palmitoyl transferase 1 (CPT 1) mRNA expression in the liver of 9 wks old to 13 wks old growing meat rabbits. One hundred and fifty 9 wks old meat rabbits were allocated to individual cages and randomly divided into five groups. Animals in each group were fed with a diet with the following LA addition concentrations: 0, 3, 6, 9 and 12 g/kg diet (as-fed basis) and LA concentrations were 0.84, 1.21, 1.34, 1.61 and 1.80% in the diet, respectively. The results showed as follows: the dietary LA levels significantly affected muscle color of LL included a* and b* of experimental rabbits (p<0.05). The linear effect of LA on serum high density lipoprotein cholesterol was obtained (p = 0.0119). The saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) contents of LL decreased and the polyunsaturated fatty acids (PUFAs) content of LL increased with dietary LA increase (p<0.0001). The PUFA n-6 content and PUFA n-3 content in the LL was significantly affected by the dietary LA levels (p<0.01, p<0.05). The MUFAs content in the liver decreased and the PUFAs contents in the liver increased with dietary LA increase (p<0.0001). The PUFA n-6 content and the PUFA n-6/n-3 ratio in the liver increased and PUFA n-3 content in the liver decreased with dietary LA increase (p<0.01). The linear effect of LA on CPT 1 mRNA expression in the liver was obtained (p = 0.0081). In summary, dietary LA addition had significant effects on liver and muscle fatty acid composition (increased PUFAs) of 9 wks old to 13 wks old growing meat rabbits, but had little effects on growth performance, meat physical traits and mRNA expression of liver relative enzyme of experimental rabbits.

Clinicopathological characteristics at primary melanoma diagnosis as risk factors for brain metastasis

To better identify melanoma patients who are, at the time of primary melanoma diagnosis, at high risk of developing brain metastases, primary melanoma characteristics were examined as risk factors for brain metastasis development. In a study of two patient cohorts, clinicopathological characteristics prospectively collected at primary cutaneous melanoma diagnosis for patients with/without brain metastasis were assessed in univariate and multivariate analyses using data from two prospectively collected databases: the Melanoma Cooperative Group (MCG) (1972-1982) and the Interdisciplinary Melanoma Cooperative Group (IMCG) (2002-2009). Candidate risk factors were evaluated in association with time to brain metastasis using either the log-rank test or Cox proportional hazards regression analysis with/without considering competing risks. Out of 2341 total patients included in the study, 222 (9.5%) developed brain metastases (median follow-up: 98 months). The median time to brain metastases was 30.5 months and the median survival time after brain metastases was 4 months. Increased hazard ratios (HRs) for brain metastasis were found among thicker (logarithmic value in mm) (MCG: HR=1.97, P<0.0001; IMCG: HR=1.31, P=0.018), ulcerated (MCG: HR=1.93, P=0.01; IMCG: HR=3.14, P<0.0001), and advanced-stage (MCG: HR=2.08, P=0.008; IMCG: HR=2.56, P=0.0002) primary melanomas on the basis of multivariate Cox regression analysis assuming the presence of competing risks. Primary cutaneous melanoma thickness, ulceration, and stage were identified and validated as risk factors associated with time to melanoma brain metastasis.

Serum microRNAs as biomarkers for recurrence in melanoma

BACKGROUND

Identification of melanoma patients at high risk for recurrence and monitoring for recurrence are critical for informed management decisions. We hypothesized that serum microRNAs (miRNAs) could provide prognostic information at the time of diagnosis unaccounted for by the current staging system and could be useful in detecting recurrence after resection.

METHODS

We screened 355 miRNAs in sera from 80 melanoma patients at primary diagnosis (discovery cohort) using a unique quantitative reverse transcription-PCR (qRT-PCR) panel. Cox proportional hazard models and Kaplan-Meier recurrence-free survival (RFS) curves were used to identify a miRNA signature with prognostic potential adjusting for stage. We then tested the miRNA signature in an independent cohort of 50 primary melanoma patients (validation cohort). Logistic regression analysis was performed to determine if the miRNA signature can determine risk of recurrence in both cohorts. Selected miRNAs were measured longitudinally in subsets of patients pre-/post-operatively and pre-/post-recurrence.

RESULTS

A signature of 5 miRNAs successfully classified melanoma patients into high and low recurrence risk groups with significant separation of RFS in both discovery and validation cohorts (p = 0.0036, p = 0.0093, respectively). Significant separation of RFS was maintained when a logistic model containing the same signature set was used to predict recurrence risk in both discovery and validation cohorts (p < 0.0001, p = 0.033, respectively). Longitudinal expression of 4 miRNAs in a subset of patients was dynamic, suggesting miRNAs can be associated with tumor burden.

CONCLUSION

Our data demonstrate that serum miRNAs can improve accuracy in identifying primary melanoma patients with high recurrence risk and in monitoring melanoma tumor burden over time.

TILs in metastatic melanoma tumors: A biomarker for immunotherapy?

8589

Background: Increased tumor infiltrating lymphocytes (TILs) in primary (P) and locoregional melanoma tissue correlate with improved clinical outcome. Our recent data have suggested that matrix metalloproteinase 23 (MMP 23) expression (exp) in P result in lower prevalence of TILs and correlate with poor clinical outcome. On this basis, we examined P and metastatic (M) melanoma tissues to assess for concordance between the presence of TILs, MMP 23 protein levels and clinical response(resp) to anti-cytotoxic T-lymphocyte antigen 4 (CTLA4) therapy (tx). Methods: 21 melanoma patients (pts) with M specimens were analyzed. 17 matched P specimens were also evaluated. Immunohistochemical (IHC) staining for TILs of the pre-anti-CTLA4 specimens were conducted and confirmed by 2 pathologists. IHC TILs were graded- 2+: >10% TILs present in multiple foci in both peri- and through the tumor; 1+: 1-10% TILs present in one or more foci in the tumor and predominantly peri-tumor; 0: no TILs were present or if the lymphocytes did not infiltrate the tumor. TILs in P and M were analyzed for concordance and potential for predictability of resp to anti-CTLA4 tx. Staining to identify lymphocyte subtypes and MMP 23 exp in M is being completed. Results: 20 pts received anti-CTLA4 tx. M analysis- 6 pts with 0 TILs in M (5 no response [NR], 1 partial response[PR]); 8 pts with 1-2+ TILs in M (1 complete response [CR], 5 PR, 2 progressive disease [PD]); 6 pts with 2+ TILs in M ( 3 CR, 2 PR, 1PD). 1 pt with 2+ TILs in M resected, no tx and 4 years disease free. TILs present in 13 P, absent in 4 P and not evaluable in 4 pts with unknown P melanoma. MMP 23 protein scores in P (range 2-4) correlated with melanoma recurrence. MMP 23 exp in M will be reported. Conclusions: TILs in P do not appear to correlate with TILs in M or predict for resp to anti-CTLA4 tx. TILs in M may be an indicator of responsiveness to anti-CTLA4 tx. Identification of the type of M TIL subsets may further refine tx recommendations.

Prognostic value of mitosis-specific antibodies and computer image analysis in calculating mitotic rate in melanoma

e19003

Background: Mitotic rate (MR) is an important part of staging for thin melanomas (≤1 mm) but its value in thick melanomas (>1 mm) has not been determined. Additionally, accurate calculation of MR on hematoxylin and eosin (H&E) stained sections can be challenging. Several mitosis-specific antibodies are commercially available but their role in predicting clinical outcome in melanoma has not been adequately assessed compared to H&E. Methods: Primary tissues from 190 cutaneous melanoma patients [≤1 mm (n = 22); >1 mm (n=168)] prospectively enrolled at New York University Medical Center were stained with MPM-2 and PHH3, two mitosis-specific antibodies. Using light microscopy, MR was quantified manually from corresponding H&E, MPM-2, and PHH3-stained sections. Computer-assisted image analysis was then applied to detect immunolabeled mitoses on the previously examined PHH3 and MPM-2 slides. We then analyzed the association between MR and progression-free survival (PFS) and melanoma-specific survival (MSS). Results: Manual quantification of PHH3-derived MR was associated with shorter PFS in thick melanomas (P=0.042). Computer-assisted quantification of PHH3 showed a significant association with shorter PFS and MSS in thick melanomas (P=0.021, P=0.04, respectively). Relative to manual analysis of corresponding H&E-stained sections, manual analysis of PHH3 and MPM-2 stains increased mean MR (86% and 159% increases, respectively). MPM-2 did not have value as mitosis-specific marker in melanoma of any thickness. Conclusions: PHH3-derived MR might be useful in predicting worse clinical outcome in primary melanoma patients with thicker melanoma.

MicroRNA alterations associated with BRAF status in melanoma

8565

Background: We hypothesize that BRAF mutations result in microRNA (miRNA) alterations which contribute to orchestrating the mutant BRAF’s oncogenic effects in melanoma. Our study is the first to examine the association between the BRAF mutation status in primary melanomas and the expression of miRNAs that target known tumor suppressors. Methods: 84 prospectively accrued melanoma patients at New York University Langone Medical Center were studied. DNA and total RNA were extracted from consecutive sections of formalin-fixed paraffin-embedded primary tissues. BRAF mutation status was determined by DNA sequencing. RNA was hybridized to miRCURY miRNA microarrays containing 1314 probes. Normalized miRNA data were analyzed using the t-test (p<0.05) to identify differentially expressed miRNAs between BRAFmut vs. BRAFwt cases. Those with an average fold change (FC) > 2 were selected for predicted (TargetScan, PicTar) and validated (miRWalk) gene target analysis, and overlapping genes targeted by ≥ 2 miRNAs were analyzed using pathway-mapping algorithms (KEGG, BioCarta, PANTHER). Results: 48 (57%) primaries were BRAFwt and 36 (43%) were BRAFmut (26 V600E, 4 V600K, 1 V600R, 1 V600D, 4 other). 30 miRNAs met the criteria for statistically significant differential expression and FC thresholding: let-7i, miR-23c, -26a/b, -27b, -34a, -98, -126*, -141, -148a, -181b, -195, -199a-3p, -199a/b-5p, -200a/b/c, -203, -205, -455-3p, -491-3p, -606, -641, -646, -1297, -4301; miRPlus-C1070, -C1110, -G1246-3p (average FC: 2.3-3.5, all increased in BRAFmut vs. BRAFwt). Predicted and validated target gene analysis revealed 317 genes, of which 110 (35%) were convergent targets of ≥ 2 miRNAs. Pathway analyses of the predicted, validated, and convergent target genes pointed to the potential impact of BRAFmut-associated miRNAs on known tumor suppressors FAS, PTEN, and TNF and the p53 pathway. Conclusions: Differentially expressed miRNAs in BRAFmut vs. BRAFwt primaries target genes with known roles in melanoma biology and/or treatment response. These miRNAs warrant further study as potential effectors of the BRAFmut oncogenic program.

The melanoma risk loci as determinants of melanoma prognosis

8557

Background: Genetic risk factors of human cancer emerge as promising markers of clinical outcome. The recent melanoma genome-wide scans (GWAS) have identified loci associated with the disease risk, nevi or UV/pigmentation, but the prognostic potential of these variants is yet to be determined. In this study, we performed the first-to-date systematic evaluation of the association between established melanoma risk loci and melanoma progression. Methods: 891 melanoma patients prospectively accrued and followed up at NYU Medical Center were studied. We examined the association of 108 melanoma susceptibility single nucleotide polymorphisms (SNPs), selected or imputed from recent GWASs on melanoma, nevi or pigmentation, with recurrence-free survival (RFS) and overall survival (OS). The genotyping was performed using Sequenom I-plex. Cox PH model was used to test the association between each SNP and RFS and OS adjusted by age at diagnosis, gender, tumor stage and histological subtype. ROC curves were used to measure predictive utility of SNPs in predicting 3-year recurrence. Results: The strong association was observed for rs7538876 (RCC2) with RFS (HR=2.445, 95% CI 1.57 – 3.8, p=0.0006) and rs9960018 (DLGAP1) with both RFS and OS (HR=4.7, 95% CI=2.11-10.43, p=0.0061, HR=1.55, 95% CI=1.11-2.17, p=0.0094, respectively) using adjusted multivariate analysis. In addition, we identified the classifier with rs7538876 and rs9960018, stage and histological type at primary tumor diagnosis, achieving a higher area under the ROC curve (AUC=84%) compared to the baseline (AUC=78%) in predicting 3-year recurrence. Univariate survival analyses have identified associations of several SNPs with ulceration and/or tumor thickness. Conclusions: Our data revealed an association between specific melanoma susceptibility variants and worse clinicopathological variables at the time of diagnosis as well as worse disease outcome. The strength of associations observed for rs7538876 and rs9960018 suggest biological implication of these loci in melanoma recurrence. The observed predictive patterns of associated variants with clinical outcome provide for the first time evidence for the potential utilization of genetic markers in melanoma prognostication.

Challenging the current paradigm of melanoma progression: brain metastasis as isolated first visceral site

Melanoma brain metastasis that develops as the isolated first visceral site challenges the current paradigm of tumor progression in which brain metastasis is regarded as the final stage. Here we test the hypothesis that melanoma patients who develop brain metastasis as the isolated first visceral site have distinct clinicopathological features at the time of primary melanoma diagnosis. Cutaneous melanoma patients enrolled in 2 prospectively collected databases were studied (Cohort 1: 1972-1982, Cohort 2: 2002-2009). Patients who developed brain metastasis as isolated first visceral site were compared with (1) all other patients, (2) patients who developed visceral metastasis: extracranial only or extracranial and brain, and (3) patients who progressed to other isolated visceral sites first. Two hundred seven of 2280 (9.1%) patients developed brain metastasis (median follow-up, 5.2 y). Seventy-four of 207 (35.7%) brain metastasis patients progressed to brain metastasis as the isolated first visceral site. These patients presented with primaries that were thinner and had no mitosis compared with all other visceral metastasis patients (Fisher's combined P = .02, .05, respectively), and there was a significant difference in American Joint Committee on Cancer stage distribution at initial melanoma diagnosis (combined P = .02). Post-visceral metastasis survival, however, was shorter in patients with brain metastasis as isolated first visceral site than in patients with visceral metastasis: extracranial and brain (combined P = .03). Brain metastasis as isolated first visceral site is a distinct clinicopathological entity. Studies are needed to better understand the biological factors driving this phenotype at the time of primary melanoma diagnosis and to determine its clinical implications.

Single versus multiple primary melanomas: old questions and new answers

BACKGROUND

In patients with multiple primary melanomas (MPM), mean tumor thickness tends to decrease from the first melanoma to the second melanoma, and prognosis may be improved compared with the prognosis for patients who have a single primary melanoma (SPM). In this study, the authors compared the clinicopathologic features of patients with MPM and SPM to better characterize the differences between these 2 groups and to determine whether or not there is an inherent difference in tumor aggression.

METHODS

In total, 788 patients with melanoma who were enrolled prospectively in the Interdisciplinary Melanoma Cooperative Group database from 2002 to 2008 were studied. Patients with SPM and with MPM were compared with regard to clinical and primary melanoma characteristics.

RESULTS

Of 788 patients with melanoma, 61 patients (7.7%) had 2 or more primary melanomas. The incidence of developing a second primary melanoma 1 year and 5 years after initial melanoma diagnosis was 4.1% and 8.7%, respectively, and most of the risk accumulated within the first year. The incidence of MPM was greater in patients aged ≥60 years than in those aged ≤60 years. The absence or presence of mitosis and other tumor characteristics did not differ significantly between patients with SPM and patients with MPM (P = .61).

CONCLUSIONS

No difference was observed in the presence or absence of mitoses, a marker of tumor proliferation, in SPM and MPM. Because it has been demonstrated that the presence of mitosis is a powerful prognostic marker, the current findings suggested that the tumors behave similarly in patients with SPM and patients with MPM. The authors concluded that differences in tumor thickness and prognosis between SPM and MPM more likely are caused by factors other than tumor biology, such as increased surveillance.

Impact of socioeconomic status and sociodemographic factors on melanoma presentation among ethnic minorities

Minority melanoma patients have worse survival. In this study, we evaluated the impact of socioeconomic and demographic factors on minority melanoma patients presenting to two different New York City hospitals (one public and one private) managed by the same multidisciplinary team. Sociodemographic and clinicopathologic characteristics were retrieved for melanoma patients presenting to Bellevue Hospital Center (BHC), a public hospital, and the New York University Cancer Institute (NYUCI), a private cancer center. Socioeconomic data was obtained from the United States Census Bureau database. The Kruskal-Wallis and chi-square tests were used to evaluate the associations between race/ethnicity and continuous and categorical variables (e.g. income, stage at presentation), respectively. Minorities comprised 2% (27/1296) of melanoma patients at the NYUCI compared to 42% (50/119) at BHC. Those presenting to the NYUCI were more likely to have a higher median household income (P = 0.05), a higher educational level (P = 0.04), and an earlier stage at presentation (P = 0.02) than those at BHC. NYUCI patients were predominantly covered by commercial insurance (70%), whereas Medicaid (62%) was common among BHC patients. Only 19% of Hispanic patients at BHC chose English as their preferred language. Our data demonstrate that language and health care system factors affect melanoma presentation in minorities.

A high proliferative index of recurrent melanoma is associated with worse survival

OBJECTIVE

Previous melanoma studies evaluating prognostic factors of survival at recurrence have focused on primary tumor characteristics and clinical variables at first recurrence. We examined the prognostic relevance of recurrent tumor proliferation.

METHODS

114 melanoma patients with available recurrent tissues who were prospectively enrolled at New York University Medical Center were studied. Standard of care prognostic variables (e.g. stage at initial diagnosis and lactate dehydrogenase level) and recurrent tissue expression of proliferative marker Ki-67 were evaluated for their association with overall survival.

RESULTS

High Ki-67 expression was observed in 57 (50%) of the 114 recurrent melanomas. On univariate analysis, the median overall survival of patients whose recurrent tumors overexpressed Ki-67 was significantly shorter than that of patients whose recurrent tumors had low Ki-67 expression (3.6 vs. 9.5 years, p = 0.03). On multivariate analysis, a high proliferative index of the recurrent melanoma remained an independent predictor of worse overall survival, controlling for stage at initial diagnosis, disease-free survival, and stage at first recurrence [HR = 2.09 (95% CI 1.24-3.54), p = 0.006].

CONCLUSIONS

Our results demonstrate the prognostic relevance of tumor proliferation in recurrent melanoma patients. Data also support restratification of risk assessment upon recurrence that considers tumor biology in addition to clinical variables evaluated as part of the standard of care.

Increased shedding of HU177 correlates with worse prognosis in primary melanoma

Background

Increased levels of cryptic collagen epitope HU177 in the sera of melanoma patients have been shown to be associated with thicker primary melanomas and with the nodular histologic subtype. In this study, we investigate the association between HU177 shedding in the sera and clinical outcome in terms of disease-free survival (DFS) and overall survival (OS).

Methods

Serum samples from 209 patients with primary melanoma prospectively enrolled in the Interdisciplinary Melanoma Cooperative Group at the New York University Langone Medical Center (mean age = 58, mean thickness = 2.09 mm, stage I = 136, stage II = 41, stage III = 32, median follow-up = 54.9 months) were analyzed for HU177 concentration using a validated ELISA assay. HU177 serum levels at the time of diagnosis were used to divide the study cohort into two groups: low and high HU177. DFS and OS were estimated by Kaplan-Meier survival analysis, and the log-rank test was used to compare DFS and OS between the two HU177 groups. Multivariate Cox proportional hazards regression models were employed to examine the independent effect of HU177 category on DFS and OS.

Results

HU177 sera concentrations ranged from 0-139.8 ng/ml (mean and median of 6.2 ng/ml and 3.7 ng/ml, respectively). Thirty-eight of the 209 (18%) patients developed recurrences, and 34 of the 209 (16%) patients died during follow-up. Higher HU177 serum level was associated with an increased rate of melanoma recurrence (p = 0.04) and with increasing mortality (p = 0.01). The association with overall survival remained statistically significant after controlling for thickness and histologic subtype in a multivariate model (p = 0.035).

Conclusions

Increased shedding of HU177 in the serum of primary melanoma patients is associated with poor prognosis. Further studies are warranted to determine the clinical utility of HU177 in risk stratification compared to the current standard of care.