Emerging role of PTEN loss in evasion of the immune response to tumours

Mutations in PTEN activate the phosphoinositide 3-kinase (PI3K) signalling network, leading to many of the characteristic phenotypic changes of cancer. However, the primary effects of this gene on oncogenesis through control of the PI3K-AKT-mammalian target of rapamycin (mTOR) pathway might not be the only avenue by which PTEN affects tumour progression. PTEN has been shown to regulate the antiviral interferon network and thus alter how cancer cells communicate with and are targeted by immune cells. An active, T cell-infiltrated microenvironment is critical for immunotherapy success, which is also influenced by mutations in DNA damage repair pathways and the overall mutational burden of the tumour. As PTEN has a role in the maintenance of genomic integrity, it is likely that a loss of PTEN affects the immune response at two different levels and might therefore be instrumental in mediating failed responses to immunotherapy. In this review, we summarise findings that demonstrate how the loss of PTEN function elicits specific changes in the immune response in several types of cancer. We also discuss ongoing clinical trials that illustrate the potential utility of PTEN as a predictive biomarker for immune checkpoint blockade therapies.

Freezing of stallion epididymal sperm

Inseminations with frozen-thawed epididymal sperm have resulted in low-pregnancy rates of mares. If fertility of epididymal sperm could be improved, it would help to preserve genetic material from stallions that have suffered severe injuries, been castrated or have died. The aim of the present study was to investigate the effect of different extenders and pre-freezing addition of capacitation media on freezability of epididymal sperm and on storage at 5 degrees C for 24h. In experiment 1, epididymal sperm samples were diluted and subsequently frozen with three different extenders: Botu-Crio, EDTA-Lactose and INRA-82. Motility analysis using computer assisted sperm analyzer (CASA) demonstrated better motility for sperm in Botu-Crio than in the other extenders; EDTA-Lactose yielded better motility than INRA-82 on most evaluated parameters. There was no difference in membrane integrity among the studied extenders. From 18 inseminated mares, 12 (66%) were pregnant 15 days after AI with frozen-thawed epididymal sperm showing that Botu-Crio was able to maintain the fertility potential. In experiment 2, the effect of incubation of epididymal sperm before freezing in three capacitation media (Fert Talp, Sperm Talp, Talp+Progesterone), seminal plasma, or control was tested. Based on post-thaw motility evaluation by CASA, samples incubated in Sperm Talp showed better motility values. There were no differences in plasma or acrosomal membranes or in mitochondrial potential among groups. We concluded that Botu-Crio was better than the other extenders in the ability to preserve epididymal sperm and that pre-freeze addition of Sperm Talp was also beneficial.

Galectin-3 disruption impaired tumoral angiogenesis by reducing VEGF secretion from TGFβ1-induced macrophages

In order to study the role of galectin-3 in tumor angiogenesis associated with tumor-associated macrophages (TAM) and tumor parenchyma, the galectin-3 expression was reconstituted in Tm1 melanoma cell line that lacks this protein. Galectin-3-expressing cells (Tm1G3) and mock-vector transfected cells (Tm1N3) were injected into wild-type (WT) and galectin-3 knockout (KO) C57Bl/6 mice. Tumors originated from Tm1G3 were larger in tumor volume with enlarged functional vessels, decreased necrotic areas, and increased vascular endothelial growth factor (VEGF) protein levels. Galectin-3-nonexpressing-cells injected into WT and KO showed increased levels of transforming growth factor beta 1 (TGFβ1) and, in WT animals this feature was also accompanied by increased VEGFR2 expression and its phosphorylation. In KO animals, tumors derived from galectin-3-expressing cells were infiltrated by CD68(+)-cells, whereas in tumors derived from galectin-3-nonexpressing-cells, CD68(+) cells failed to infiltrate tumors and accumulated in the periphery of the tumor mass. In vitro studies showed that Tm1G3 secreted more VEGF than Tm1N3 cells. In the latter case, TGFβ1 induced VEGF production. Basal secretion of VEGF was higher in WT-bone marrow-derived macrophages (BMDM) than in KO-BMDM. TGFβ1 induced secretion of VEGF only in WT-BMDM. Tm1G3-induced tumors had the Arginase I mRNA increased, which upregulated alternative macrophage (M2)/TAM induction. M2 stimuli, such as interleukin-4 (IL4) and TGFβ1, increased Arginase I protein levels and galectin-3 expression in WT- BMDM, but not in cells from KO mice. Hence, we report that galectin-3 disruption in tumor stroma and parenchyma decreases angiogenesis through interfering with the responses of macrophages to the interdependent VEGF and TGFβ1 signaling pathways.

Epithelial-Mesenchymal Transition Signaling and Prostate Cancer Stem Cells: Emerging Biomarkers and Opportunities for Precision Therapeutics

Prostate cancers may reactivate a latent embryonic program called the epithelial-mesenchymal transition (EMT) during the development of metastatic disease. Through EMT, tumors can develop a mesenchymal phenotype similar to cancer stem cell traits that contributes to metastasis and variation in therapeutic responses. Some of the recurrent somatic mutations of prostate cancer affect EMT driver genes and effector transcription factors that induce the chromatin- and androgen-dependent epigenetic alterations that characterize castrate-resistant prostate cancer (CRPC). EMT regulators in prostate cancer comprise transcription factors (SNAI1/2, ZEB1, TWIST1, and ETS), tumor suppressor genes (RB1, PTEN, and TP53), and post-transcriptional regulators (miRNAs) that under the selective pressures of antiandrogen therapy can develop an androgen-independent metastatic phenotype. In prostate cancer mouse models of EMT, Slug expression, as well as WNT/β-Catenin and notch signaling pathways, have been shown to increase stemness potential. Recent single-cell transcriptomic studies also suggest that the stemness phenotype of advanced prostate cancer may be related to EMT. Other evidence correlates EMT and stemness with immune evasion, for example, activation of the polycomb repressor complex I, promoting EMT and stemness and cytokine secretion through RB1, TP53, and PRC1. These findings are helping clinical trials in CRPC that seek to understand how drugs and biomarkers related to the acquisition of EMT can improve drug response.

The Role of Somatic Mutations on the Immune Response of the Tumor Microenvironment in Prostate Cancer

Immunotherapy has improved patient survival in many types of cancer, but for prostate cancer, initial results with immunotherapy have been disappointing. Prostate cancer is considered an immunologically excluded or cold tumor, unable to generate an effective T-cell response against cancer cells. However, a small but significant percentage of patients do respond to immunotherapy, suggesting that some specific molecular subtypes of this tumor may have a better response to checkpoint inhibitors. Recent findings suggest that, in addition to their function as cancer genes, somatic mutations of PTEN, TP53, RB1, CDK12, and DNA repair, or specific activation of regulatory pathways, such as ETS or MYC, may also facilitate immune evasion of the host response against cancer. This review presents an update of recent discoveries about the role that the common somatic mutations can play in changing the tumor microenvironment and immune response against prostate cancer. We describe how detailed molecular genetic analyses of the tumor microenvironment of prostate cancer using mouse models and human tumors are providing new insights into the cell types and pathways mediating immune responses. These analyses are helping researchers to design drug combinations that are more likely to target the molecular and immunological pathways that underlie treatment failure.

Pan-cancer genomic analysis shows hemizygous PTEN loss tumors are associated with immune evasion and poor outcome

In tumors, somatic mutations of the PTEN suppressor gene are associated with advanced disease, chemotherapy resistance, and poor survival. PTEN loss of function may occur by inactivating mutation, by deletion, either affecting one copy (hemizygous loss) leading to reduced gene expression or loss of both copies (homozygous) with expression absent. Various murine models have shown that minor reductions in PTEN protein levels strongly influence tumorigenesis. Most PTEN biomarker assays dichotomize PTEN (i.e. presence vs. absence) ignoring the role of one copy loss. We performed a PTEN copy number analysis of 9793 TCGA cases from 30 different tumor types. There were 419 (4.28%) homozygous and 2484 (25.37%) hemizygous PTEN losses. Hemizygous deletions led to reduced PTEN gene expression, accompanied by increased levels of instability and aneuploidy across tumor genomes. Outcome analysis of the pan-cancer cohort showed that losing one copy of PTEN reduced survival to comparable levels as complete loss, and was associated with transcriptomic changes controlling immune response and the tumor microenvironment. Immune cell abundances were significantly altered for PTEN loss, with changes in head and neck, cervix, stomach, prostate, brain, and colon more evident in hemizygous loss tumors. These data suggest that reduced expression of PTEN in tumors with hemizygous loss leads to tumor progression and influences anticancer immune response pathways.

Spatial analysis of the risk for canine visceral leishmaniasis in an urban area in the State of Sergipe

Visceral Leishmaniasis is included among the neglected tropical diseases, being directly related to conditions of social vulnerability, in urban environments, dogs act as important reservoirs. The aim of the study was to evaluate the distribution of dogs, related risk factors and identify of volatile organic compounds from infected dogs. Peripheral blood samples from 72 dogs were collected for detection using the ELISA test, in addition to hair samples for analysis by GC-MS. Of the evaluated dogs, 13 (18.05%/72) were reactive for canine VL, seven in Aracaju and six in Propriá. Factors related to vegetation, age, place where the dog stays and free access to the street, were associated with a greater chance of the dog becoming infected. Fifty-three compounds were identified from ten canine hair samples, among which 2-butoxyethanol, benzaldehyde, decane, 2-phenylacetaldehyde, nonan-1-ol, 2-phenoxyethanol, nonanoic acid, 8-heptadecene and eicosane were found in seropositive dogs for leishmaniasis. The guardian's posture has been increasingly important, requiring more attention to the dog's health and actions aimed at environmental management in an attempt to reduce cases of canine VL in the state. Even though the identified VOCs have not been associated with leishmanial infection, it is of great use for understanding canine hair substances.

Wildlife roadkill hotspots on roads crossing Conservation Units in the State of Sergipe, Brazil

Roadkill of wild animals is a significant threat to biodiversity in Brazil, causing numerous animal deaths annually. This study aimed to identify the main locations of roadkill of wild animals on two highways that pass through Conservation Units in the state of Sergipe, Brazil, examining the correlation between roadkill and dry and rainy seasons. From November 2021 to October 2022, 49 surveys were carried out along BR-235, near Serra de Itabaiana National Park, and on the Adil Dantas do Amor Cardoso highway (ADAC), crossing the Mata do Crasto Private Natural Heritage Reserve. The campaigns were carried out on motorcycles, traveling at a speed between 20 and 60 km/h. To identify roadkill points for each highway, Kernel density estimation and species accumulation curves with area extrapolation (Bootstrap) were used, and mortality rates, the 2D K-Ripley test to test the randomness of roadkills and Shannon's diversity index (H'). On BR-235, 63 roadkills were recorded and an average mortality rate of 0.0652 individuals/Km/day, while on the Adil Dantas do Amor Cardoso highway, which has implemented mitigating measures, 15 occurrences were recorded with an average mortality rate of 0.1430 individuals/Km/day. Attraction points generated by the presence of improperly discarded carcasses on BR-235 were also identified. Although not significant, the BR-235 highway showed a positive correlation between precipitation and the frequency of roadkill (rs=0.1426, p=0.5851), while ADAC showed a negative correlation for the same variables (rs=-0.1749, p=0.5675). Understanding the patterns of roadkill and the needs of highways is essential for the development of effective strategies and the establishment of effective mitigation measures, thus minimizing the negative impacts of highways on biodiversity.

Abstract 6099: Differential gene expression related to TMPRSS2-ERG fusion, CDK12, RB1, TP53, AR and ZEB1 based on transcriptomic analysis of the TCGA PRAD cohort

Prostate Cancer (PCa) is considered an immunologically excluded tumor, unable to generate an effective T-cell response against cancer cells. Inactivating mutations of the PTEN tumor suppressor are one of the most common events in human malignancies that contribute to tumorigenesis by affecting many cancer Hallmark pathways. The CDK12, RB1, TP53, AR and ZEB1 genes have been variously implicated in pathways of PCa progression and immune evasion. Here, we present a comprehensive analysis of The Cancer Genome Atlas derived PCa cohort (n=488, 96 homozygous and 64 hemizygous PTEN loss). Differential gene expression (DGE) and pathway enrichment analysis were performed for all five genes using the DESeq2 tool from the Bioconductor package for R. All comparisons were designed to compensate for gene expression changes caused by PTEN loss (Table 1).

Functional pathway analysis showed that fusion positive samples presented several downregulated pathways, including leukocyte mediated cytotoxicity, IFN type I response and IFN-γ production. AR high presented upregulation of pathways such as DNA replication and chromatin remodeling, while AR low presented upregulation of pathways such as T cell activation and lymphocyte proliferation. ZEB1 high presented a wide range of enriched pathways, including upregulation of mesenchymal cell differentiation and T cell activation. CDK12-Hom group exhibited upregulation of T cell activation, T cell differentiation and IFN-γ production. TP53 mutation revealed upregulation of various pathways including DNA replication and cell division. RB1 loss showed enrichment of pathways such as T cell activation and lymphocyte activation. Our analysis showed that variation in these five genes can promote gene expression changes associated with clinically relevant pathways independently of PTEN and that AR, CDK12, TMPRSS2-ERG fusion, ZEB1 and RB1 status are potential biomarkers for immunotherapy response.

Table 1. Differential genes expression results summary Comparison # of upregulated (LFC>0) # of downregulated (LFC<0) Fusion positive vs. Fusion negative 2997 5418 AR low vs. AR medium 4133 4167 AR high vs. AR medium 4365 2589 CDK12-Hom vs. CDK12 WT 2416 713 CDK12-Hem vs. CDK12 WT 704 387 ZEB1 high vs. ZEB1 normal 6439 6792 RB1 mut vs. RB1 WT 78 335 TP53 mut vs. TP43 WT 859 1193

Citation Format: William Lautert-Dutra, Camila Morais Melo, Luiz Paulo Chaves, André Luiz Caliari, Francisco Cesar Souza Silva, Jeremy Andrew Squire. Differential gene expression related to TMPRSS2-ERG fusion, CDK12, RB1, TP53, AR and ZEB1 based on transcriptomic analysis of the TCGA PRAD cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6099.

[Gastric liposarcoma: report of a case]

The authors present a case of a well differentiated gastric liposarcoma. The tumor was situated in the submucosa of the antrum, had a diameter of 9 cm, and showed well defined borders. A subtotal gastrectomy with BI reconstruction was performed. No abdominal metastases were observed. The patient is in good condition, without recurrence of the tumor 19 months after its removal.

Investigating the Role of SNAI1 and ZEB1 Expression in Prostate Cancer Progression and Immune Modulation of the Tumor Microenvironment

Prostate cancer (PCa) is an immunologically cold tumor and the molecular processes that underlie this behavior are poorly understood. In this study, we investigated a primary cohort of intermediate-risk PCa (n = 51) using two NanoString profiling panels designed to study cancer progression and immune response. We identified differentially expressed genes (DEGs) and pathways associated with biochemical recurrence (BCR) and clinical risk. Confirmatory analysis was performed using the TCGA-PRAD cohort. Noteworthy DEGs included collagens such as COL1A1, COL1A2, and COL3A1. Changes in the distribution of collagens may influence the immune activity in the tumor microenvironment (TME). In addition, immune-related DEGs such as THY1, IRF5, and HLA-DRA were also identified. Enrichment analysis highlighted pathways such as those associated with angiogenesis, TGF-beta, UV response, and EMT. Among the 39 significant DEGs, 11 (28%) were identified as EMT target genes for ZEB1 using the Harmonizome database. Elevated ZEB1 expression correlated with reduced BCR risk. Immune landscape analysis revealed that ZEB1 was associated with increased immunosuppressive cell types in the TME, such as naïve B cells and M2 macrophages. Increased expression of both ZEB1 and SNAI1 was associated with elevated immune checkpoint expression. In the future, modulation of EMT could be beneficial for overcoming immunotherapy resistance in a cold tumor, such as PCa.