Switchable Coacervate Formation via Amino Acid Functionalization of Poly(dehydroalanine).

Our group recently developed a family of side-chain amino acid-functionalized poly(S-alkyl-l-homocysteines), Xaa-CH (Xaa = generic amino acid), which possess the ability to form environmentally responsive coacervates in water. In an effort to further study how the molecular structure affects polypeptide coacervate formation, we prepared side-chain amino acid-functionalized poly(S-alkyl-rac-cysteines), Xaa-rac-C, via post-polymerization modification of poly(dehydroalanine), ADH. The use of the ADH platform allowed straightforward synthesis of a diverse range of side-chain amino acid-functionalized polypeptides via direct reaction of unprotected l-amino acid 2-mercaptoethylamides with ADH. Despite their differences in the main-chain structure, we found that Xaa-rac-C can form coacervates with properties similar to those seen with Xaa-CH. These results suggest that the incorporation of side-chain amino acids onto polypeptides may be a way to generally favor coacervation. The incorporation of l-methionine in Met-rac-C allowed the preparation of coacervates with improved stability against high ionic strength media. Further, the presence of additional thioether groups in Met-rac-C resulted in an increased solubility change upon oxidation allowing facile reversible redox switching of coacervate formation in aqueous media.

Primary Alveolar Soft-Part Sarcoma (ASPS) of the Prostate: Report of a Deceptive Case.

Alveolar soft-part sarcoma (ASPS) is a rare soft tissue tumor that primarily involves the extremities. We report a case of a 30-year-old never-smoker man who presented with hematuria, dysuria, and constipation at an outside hospital. He was diagnosed with and treated for multiple episodes of urinary tract infection. However, he continued to have voiding symptoms for which a cystoscopy was performed and revealed a bladder neck mass. He underwent transurethral resection of a bladder tumor and was diagnosed with muscle-invasive urothelial carcinoma, nested variant, at an outside hospital. Subsequent to this diagnosis he transferred his care to our center. In-house imaging revealed a large vascular mass involving the prostate and pushing against the bladder base. Prostate needle biopsies were performed and revealed an epithelioid neoplasm with a nested growth pattern composed of cells with a moderate amount of eosinophilic cytoplasm, mildly pleomorphic nuclei, and occasional prominent nucleoli. Since the findings were not classic for urothelial carcinoma or for prostate cancer, we included a wider differential of poorly differentiated carcinoma, sarcoma, and paraganglioma. A wide panel of keratin stains was negative, ETS (erythroblast transformation-specific)-related gene highlighted an extensive vascular network and neuroendocrine stains were all negative. A transcription factor E3 fluorescent in-situ hybridization was positive and subsequently, an ASPSCR1 gene rearrangement was demonstrated. The outside hospital transurethral resection of bladder tumor was obtained for review and the tumor was morphologically similar to that seen on the in-house prostate needle biopsies. Based on the above findings a final diagnosis of primary ASPS of the prostate with involvement of the bladder was made. The patient was later diagnosed with bilateral lung metastases. He was treated with pazopanib, radiation therapy, and cystoprostatectomy and is symptom-free on a 15-month follow-up.

Inherited TP53 Variants and Risk of Prostate Cancer.

BACKGROUND: Inherited germline TP53 pathogenic and likely pathogenic variants (gTP53) cause autosomal dominant multicancer predisposition including Li-Fraumeni syndrome (LFS). However, there is no known association of prostate cancer with gTP53. OBJECTIVE: To determine whether gTP53 predisposes to prostate cancer. DESIGN, SETTING, AND PARTICIPANTS: This multi-institutional retrospective study characterizes prostate cancer incidence in a cohort of LFS males and gTP53 prevalence in a prostate cancer cohort. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We evaluated the spectrum of gTP53 variants and clinical features associated with prostate cancer. RESULTS AND LIMITATIONS: We identified 31 prostate cancer cases among 163 adult LFS males, including 26 of 54 aged ≥50 yr. Among 117 LFS males without prostate cancer at the time of genetic testing, six were diagnosed with prostate cancer over a median (interquartile range [IQR]) of 3.0 (1.3-7.2) yr of follow-up, a 25-fold increased risk (95% confidence interval [CI] 9.2-55; p < 0.0001). We identified gTP53 in 38 of 6850 males (0.6%) in the prostate cancer cohort, a relative risk 9.1-fold higher than that of population controls (95% CI 6.2-14; p < 0.0001; gnomAD). We observed hotspots at the sites of attenuated variants not associated with classic LFS. Two-thirds of available gTP53 prostate tumors had somatic inactivation of the second TP53 allele. Among gTP53 prostate cancer cases in this study, the median age at diagnosis was 56 (IQR: 51-62) yr, 44% had Gleason ≥8 tumors, and 29% had advanced disease at diagnosis. CONCLUSIONS: Complementary analyses of prostate cancer incidence in LFS males and gTP53 prevalence in prostate cancer cohorts suggest that gTP53 predisposes to aggressive prostate cancer. Prostate cancer should be considered as part of LFS screening protocols and TP53 considered in germline prostate cancer susceptibility testing. PATIENT SUMMARY: Inherited pathogenic variants in the TP53 gene are likely to predispose men to aggressive prostate cancer.

Association of Inherited Mutations in DNA Repair Genes with Localized Prostate Cancer.

BACKGROUND: Identification of germline mutations in DNA repair genes has significant implications for the personalized treatment of individuals with prostate cancer (PrCa). OBJECTIVE: To determine DNA repair genes associated with localized PrCa in a diverse academic biobank and to determine genetic testing burden. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional study of 2391 localized PrCa patients was carried out. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Genetic ancestry and mutation rates (excluding somatic interference) in 17 DNA repair genes were determined in 1588 localized PrCa patients and 3273 cancer-free males. Burden testing within individuals of genetically determined European (EUR) and African (AFR) ancestry was performed between biobank PrCa cases and cancer-free biobank and gnomAD males. RESULTS AND LIMITATIONS: AFR individuals with localized PrCa had lower DNA repair gene mutation rates than EUR individuals (1.4% vs 4.0%, p = 0.02). Mutation rates in localized PrCa patients were similar to those in biobank and gnomAD controls (EUR: 4.0% vs 2.8%, p = 0.15, vs 3.1%, p = 0.04; AFR: 1.4% vs 1.8%, p = 0.8, vs 2.1%, p = 0.5). Gene-based rare variant association testing revealed that only BRCA2 mutations were significantly enriched compared with gnomAD controls of EUR ancestry (1.0% vs 0.28%, p = 0.03). Of the participants, 21% and 11% met high-risk and very-high-risk criteria; of them, 3.7% and 6.2% had any germline genetic mutation and 1.0% and 2.5% had a BRCA2 mutation, respectively. Limitations of this study include an analysis of a relatively small, single-institution cohort. CONCLUSIONS: DNA repair gene germline mutation rates are low in an academic biobank cohort of localized PrCa patients, particularly among individuals of AFR genetic ancestry. Mutation rates in genes with published evidence of association with PrCa exceed 2.5% only in high-risk, very-high-risk localized, and node-positive PrCa patients. These findings highlight the importance of risk stratification in localized PrCa patients to identify appropriate patients for germline genetic testing. PATIENT SUMMARY: In the majority of patients who develop localized prostate cancer, germline genetic testing is unlikely to reveal an inherited DNA repair mutation, regardless of race. High-risk features increase the possibility of a germline DNA repair mutation.

Leukemia Cutis With Histopathologic and Immunophenotypic Features Resembling S100-Negative CD1a-Positive Cutaneous Histiocytosis.

ABSTRACT: S100-negative CD1a-positive cutaneous histiocytosis is an exceedingly rare histiocytosis that is defined histopathologically by a dense dermal infiltrate of ovoid mononuclear cells with grooved nuclei and ample cytoplasm with variable nuclear atypia and mitoses that are immunohistochemically positive for CD1a and negative for S100 and CD207 (langerin). The histogenesis of S100-negative CD1a-positive histiocytosis is unclear, and its precursor cell has yet to be characterized. Although all cases thus far have been described as benign and occasionally self-resolving, the clinical course and outcome of this disease are not fully understood. This case expands the spectrum of disease associated with S100-negative CD1a-positive histiocytosis given its malignant course.