Multinational, Multicenter Evaluation of Prostate Cancer Tissue in Sub-Saharan Africa: Challenges and Opportunities.

PURPOSE: Prostate cancer disproportionately affects men of African descent, yet their representation in tissue-based studies is limited. This multinational, multicenter pilot study aims to establish the groundwork for collaborative research on prostate cancer in sub-Saharan Africa. METHODS: The Men of African Descent and Carcinoma of the Prostate network formed a pathologist working group representing eight institutions in five African countries. Formalin-fixed paraffin-embedded prostate tissue specimens were collected from Senegal, Nigeria, and Ghana. Histology slides were produced and digitally scanned. A central genitourinary pathologist (P.L.) and eight African general pathologists reviewed anonymized digital whole-slide images for International Society of Urological Pathology grade groups and other pathologic parameters. Discrepancies were re-evaluated, and consensus grading was assigned. A virtual training seminar on prostate cancer grading was followed by a second assessment on a subcohort of the same tissue set. RESULTS: Of 134 tissue blocks, 133 had evaluable tissue; 13 lacked cancer evidence, and four were of insufficient quality. Post-training, interobserver agreement for grade groups improved to 56%, with a median Cohen's quadratic weighted kappa of 0.83 (mean, 0.74), compared with an initial 46% agreement and a quadratic weighted kappa of 0.77. Interobserver agreement between African pathologist groups was 40%, with a quadratic weighted kappa of 0.66 (95% CI, 0.51 to 0.76). African pathologists tended to overgrade (36%) more frequently than undergrade (18%) compared with the reference genitourinary pathologist. Interobserver variability tended to worsen with a decrease in tissue quality. CONCLUSION: Tissue-based studies on prostate cancer in men of African descent are essential for a better understanding of this common disease. Standardized tissue handling protocols are crucial to ensure good tissue quality and data. The use of digital slide imaging can enhance collaboration among pathologists in multinational, multicenter studies.

Telomere Transcription in MLL-Rearranged Leukemia Cell Lines: Increased Levels of TERRA Associate with Lymphoid Lineage and Are Independent of Telomere Length and Ploidy.

Telomere transcription into telomeric repeat-containing RNA (TERRA) is an integral component of all aspects of chromosome end protection consisting of telomerase- or recombination-dependent telomere elongation, telomere capping, and the preservation of the (sub)telomeric heterochromatin structure. The chromatin modifier and transcriptional regulator MLL binds to telomeres and regulates TERRA transcription in telomere length homeostasis and response to telomere dysfunction. MLL fusion proteins (MLL-FPs), the product of MLL rearrangements in leukemia, also bind to telomeric chromatin. However, an effect on telomere transcription in MLL-rearranged (MLL-r) leukemia has not yet been evaluated. Here, we show increased UUAGGG repeat-containing RNA levels in MLL-r acute lymphoblastic leukemia (ALL) when compared to non-MLL-r ALL and myeloid leukemia. MLL rearrangements do not affect telomere length and UUAGGG repeat-containing RNA levels correlate with mean telomere length and reflect increased levels of TERRA. Furthermore, high levels of TERRA in MLL-r ALL occur in the presence of telomerase activity and are independent of ploidy, an underestimated source of variation on the overall transcriptome size in a cell. This MLL rearrangement-dependent and lymphoid lineage-associated increase in levels of TERRA supports a sustained telomere transcription by MLL-FPs that correlates with marked genomic stability previously reported in pediatric MLL-r ALL.

Macrophage-Derived Cholesterol Contributes to Therapeutic Resistance in Prostate Cancer.

Castration-resistant prostate cancer (CRPC) is a lethal stage of disease in which androgen receptor (AR) signaling is persistent despite androgen deprivation therapy (ADT). Most studies have focused on investigating cell-autonomous alterations in CRPC, while the contributions of the tumor microenvironment are less well understood. Here we sought to determine the role of tumor-associated macrophages in CRPC, based upon their role in cancer progression and therapeutic resistance. In a syngeneic model that reflected the mutational landscape of CRPC, macrophage depletion resulted in a reduced transcriptional signature for steroid and bile acid synthesis, indicating potential perturbation of cholesterol metabolism. As cholesterol is the precursor of the five major types of steroid hormones, we hypothesized that macrophages were regulating androgen biosynthesis within the prostate tumor microenvironment. Macrophage depletion reduced androgen levels within prostate tumors and restricted AR nuclear localization in vitro and in vivo. Macrophages were also cholesterol-rich and were able to transfer cholesterol to tumor cells in vitro. AR nuclear translocation was inhibited by activation of liver X receptor (LXR)-ß, the master regulator of cholesterol homeostasis. Consistent with these data, macrophage depletion extended survival during ADT and the presence of macrophages correlated with therapeutic resistance in patient-derived explants. Taken together, these findings support the therapeutic targeting of macrophages in CRPC. SIGNIFICANCE: These results suggest that macrophage-targeted therapies can be combined with androgen deprivation therapy to treat patients with prostate cancer by limiting cholesterol bioavailability and the production of intratumoral androgens.See related commentary by Al-Janabi and Lewis, p. 5399.

Comparative Genomics Reveals Distinct Immune-oncologic Pathways in African American Men with Prostate Cancer.

PURPOSE: The role of immune-oncologic mechanisms of racial disparities in prostate cancer remains understudied. Limited research exists to evaluate the molecular underpinnings of immune differences in African American men (AAM) and European American men (EAM) prostate tumor microenvironment (TME). EXPERIMENTAL DESIGN: A total of 1,173 radiation-naïve radical prostatectomy samples with whole transcriptome data from the Decipher GRID registry were used. Transcriptomic expressions of 1,260 immune-specific genes were selected to assess immune-oncologic differences between AAM and EAM prostate tumors. Race-specific differential expression of genes was assessed using a rank test, and intergene correlational matrix and gene set enrichment was used for pathway analysis. RESULTS: AAM prostate tumors have significant enrichment of major immune-oncologic pathways, including proinflammatory cytokines, IFNα, IFNγ, TNFα signaling, ILs, and epithelial-mesenchymal transition. AAM TME has higher total immune content score (ICSHIGH) compared with 0 (37.8% vs. 21.9%, P = 0.003). AAM tumors also have lower DNA damage repair and are genomically radiosensitive as compared with EAM. IFITM3 (IFN-inducible transmembrane protein 3) was one of the major proinflammatory genes overexpressed in AAM that predicted increased risk of biochemical recurrence selectively for AAM in both discovery [HRAAM = 2.30; 95% confidence interval (CI), 1.21-4.34; P = 0.01] and validation (HRAAM = 2.42; 95% CI, 1.52-3.86; P = 0.0001) but not in EAM. CONCLUSIONS: Prostate tumors of AAM manifest a unique immune repertoire and have significant enrichment of proinflammatory immune pathways that are associated with poorer outcomes. Observed immune-oncologic differences can aid in a genomically adaptive approach to treating prostate cancer in AAM.

Proof-of-principle Phase I results of combining nivolumab with brachytherapy and external beam radiation therapy for Grade Group 5 prostate cancer: safety, feasibility, and exploratory analysis.

BACKGROUND: To determine whether combining brachytherapy with immunotherapy is safe in prostate cancer (PCa) and provides synergistic effects, we performed a Phase I/II trial on the feasibility, safety, and benefit of concurrent delivery of anti-PD-1 (nivolumab) with high-dose-rate (HDR) brachytherapy and androgen deprivation therapy (ADT) in patients with Grade Group 5 (GG5) PCa. METHODS: Eligible patients were aged 18 years or older with diagnosis of GG5 PCa. Patients received ADT, nivolumab every two weeks for four cycles, with two cycles prior to first HDR, and two more cycles prior to second HDR, followed by external beam radiotherapy. The primary endpoint was to determine safety and feasibility. This Phase I/II trial is registered with ClinicalTrials.gov (NCT03543189). RESULTS: Between September 2018 and June 2019, six patients were enrolled for the Phase I safety lead-in with a minimum observation period of 3 months after nivolumab administration. Overall, nivolumab was well tolerated in combination with ADT and HDR treatment. One patient experienced a grade 3 dose-limiting toxicity (elevated Alanine aminotransferase and Aspartate aminotransferase) after the second cycle of nivolumab. Three patients (50%) demonstrated early response with no residual tumor detected in ≥4 of 6 cores on biopsy post-nivolumab (4 cycles) and 1-month post-HDR. Increase in CD8+ and FOXP3+/CD4+ T cells in tissues, and CD4+ effector T cells in peripheral blood were observed in early responders. CONCLUSION: Combination of nivolumab with ADT and HDR is well tolerated and associated with evidence of increased immune infiltration and antitumor activity.

MLL associates with telomeres and regulates telomeric repeat-containing RNA transcription.

Mammalian telomeres consist of TTAGGG repeats organized in nucleosomes and associated with a six-protein complex known as shelterin, which preserves telomere structure and protects chromosome ends from the cellular DNA damage response. Recent studies have found that telomeres are transcribed into telomeric UUAGGG repeat-containing RNA (TERRA) starting from subtelomeric regions. TERRA binding at telomeres appears to be involved in cis-based mechanisms of telomeric chromatin organization and maintenance. A number of histone methyltransferases (HMTs) are known to influence telomeric chromatin status; however, the regulatory mechanisms of telomere transcription are poorly understood. Here, we show that the histone 3/lysine 4 (H3/K4) HMT and the transcriptional regulator MLL associate with telomeres and contribute to their H3/K4 methylation and transcription in a telomere length-dependent manner. In human diploid fibroblasts, RNA interference-mediated MLL depletion affects telomere chromatin modification and transcription and induces the telomere damage response. Telomere uncapping through either TRF2 shelterin protein knockdown or exposure to telomere G-strand DNA oligonucleotides significantly increases the transcription of TERRA, an effect mediated by the functional cooperation between MLL and the tumor suppressor p53. In total, our findings identify a previously unrecognized role of MLL in modifying telomeric chromatin and provide evidence for the functional interaction between MLL, p53, and the shelterin complex in the regulation of telomeric transcription and stability.

The amino acid sequences flanking an antigenic determinant can strongly affect MHC class I cross-presentation without altering direct presentation.

Direct presentation (DP) and cross presentation (CP) on MHC I by professional APCs are defined by the internal or external source of the Ag, respectively. Although some Ags are substrates for both DP and CP, others are only substrates for DP. The reasons for this difference remain largely unknown. In this study, we studied in tissue culture and also in vivo, the effects of altering the length and sequence of the amino acid chains flanking an MHC class I restricted determinant (the chicken OVA OVA(258-265), SIINFEKL) that is normally a good substrate for both DP and CP. We demonstrate that CP but not DP strictly requires flanking N and C-terminal extensions of minimal length. Furthermore, we show that removal but not replacement of just one amino acid 22 residues downstream from the determinant is sufficient to strongly affect CP without affecting either protein stability or DP. Thus, our work shows that the flanking residues of an antigenic determinant can differentially affect CP and DP, and that features of the Ag other than half-life can have a major impact in CP. Our studies may have implications for understanding CP in viral infections and possibly for the design of new vaccines.

Cutting edge: efficient MHC class I cross-presentation during early vaccinia infection requires the transfer of proteasomal intermediates between antigen donor and presenting cells.

Priming of CD8(+) T cells requires presentation of short peptides bound to MHC class I molecules of professional APCs. Cross-presentation is a mechanism whereby professional APC present on their own MHC class I molecules peptides derived from degradation of Ags synthesized by other Ag "donor cells." The mechanism of cross-presentation is poorly understood, and the nature of the transferred Ag is unknown. In this report, we demonstrate that the bulk of a cross-presented Ag transferred from donor cells recently infected with vaccinia virus are proteasomal products that are susceptible to peptidases within the donor cell cytosol and not full-length proteins or mature epitopes either free or bound to chaperones.

Evaluacion nutricional e inmunologica de pacientes con cancer gastrico antes y despues de la cirugia / Nutritional and inmunological assessement of patients with gastric cancer before and after surgery

El principal objetivo fue evaluar el estado nutrícional e inmunológico del paciente, como un indicador predictivo de la morbilidad y de la mortalidad en pacientes con cáncer gástrico. Se realizó un estudio clínico en perspectiva en el Instituto nacional de Cancerologia en Bogotá, D. C. nuestro grupo de estudio estaba conformado por 40 pacientes con diagnóstico de adenocarcinoma que fue tratado quirúrgicamente. Se tomaron muestras de sangre antes y cinco días después de la cirugía; se hizo la clasificación de las células mononucleares por el método de citometría de flujo permitiendo un análisis bicolor, y se obtuvo la evaluación nutricional mediante la medición de los niveles de albúmina, la pérdida del peso promedio y el índice de riesgo nutricional (IRU). Se localizó la mitad de las malignidades en el tercio medio e inferior del estómago: estado I, 17.55 por ciento; estado II, 10 por ciento; estado III, 55 por ciento, y estado, IV 17.5 por ciento. 5e realizaron 20 gastrectomías subtotales, 11 gastrectomías totales, 7 gastroyeyunostomías y 2 esofagogastrectomías con la resección de los nodos linfáticos DI y D2-D3. Se observó una morbilidad posoperatoria del 22.5 por ciento y una mortalidad del 7.5 por ciento. Se identificó una inmunosupresión celular preoperatoria, con una relación linfocito auxiliar (CD4) y linfocito supresor/ citotóxico (CD8) de 1.38, como valor normal (nV> 1.5), que se incrementó de acuerdo con el estado de la enfermedad. Los pacientes que murieron presentaban una inmunosupreslón celular preoperatoría, significativamente mayor de aquellos que sobrevivieron (P = 0.05). La mortalidad postoperatoria estaba correlacionada significativamente con la hipoalbuminemia (P= 0.008). En quienes murieron, la pérdida de peso fue mayor que en los sobrevivientes (P = 0.06). Los pacientes con desnutrición severa tuvieron mortalidad posoperatoria mayor de acuerdo con el IRN. La inmunosupresión celular severa previa a la cirugía (CD4/CD8 < 1). la hipoalbuminemia, la pérdida de peso y el IRN severo, tuvieron un valor positivo predictivo para la mortalidad en los pacientes con cáncer gástrico

Carcinoma escamolecular de cavida oralL: expression de HLA, niveles de proteina trasportadora de retinol y presencia de virus de papiloma humano / Oral cavity squamous cell carcinoma: HLA expression retinol bearting protein levels and human papilomavirus

El carcinoma escamocelular de cavidad oral (CECO) presenta aspectos nutricionales, virológicos e inmunológicos importantes para el entendimiento de su biología e historia natural, los cuales son revisados con miras a aportar nuevos conceptos en cuanto al pronóstico, seguimiento y manejo del paciente oncológico. se hace un reporte preliminar de casos estudiados en el INC-ESE. A las biopsias de 10 pacientes con diagnóstico de CECO, se les hizo análisis histopatológico y detección de moléculas de histocompatibilidad (MHC) por inmunoperoxidasa. Se detectó DNA de HPV por PCR. Se determinaron los niveles séricos de Proteína Trasportadora de Retinol (PTR) y la respuesta de anticuerpos anti-HPV por ELISA. A todos los casos se les confirmó el diagnóstico de CECO, presentando 3 de ellos concomitannte, lesiones premalignas. El consumo de tabaco y alcohol se observó en 5 y 3 de los pacientes respectivamente. Se detectó DNA de HPV en 2 casos, uno con HPV 6/11, y otro con tipo no determinado. El análisis inmunohistoquímico mostró una disminución de las MHC clase I, sobre todoso los casos positivos para DNA de HPV y los niveles de PTR se encontraban disminuidos; no se detectaron en ningún caso anticuerpos anti-HPV. Los dos casos positivos para HPV no presentaban exposición a alcohol o tabaco, sugiriendo que estos pueden representar un subgrupo de pacientes con CECO en el cual el HPV juega un papel central en el desarrollo de la neoplasia. La disminución de expresión de las moléculas de histocompatibilidad de clase I fue más evidente en los casos positivos para DNA de HPV, lo cual podría ser un factor crítico de progresión por falata de generación de células T citotóxicas que controlen el crecimiento tumoral. Se encontraron niveles bajos de PTR en los casos comparados con los controles; en los casos HPV positivos, estos niveles no fueron los más reducidos, lo cual podría indicar que en este grupo con infección viral, no es necesaria la deficiencia de vitamina A para la progresión de la enfermedad.El seguimiento y tratameinto de pacientes con CECO podría mejorarse si se tienen en cuenta estos factores y la importancia de una historia natural distinta relacionada con un agente infecciosos como el HPV.