Chordoma cancer stem cell subpopulation characterization may guide targeted immunotherapy approaches to reduce disease recurrence.

Introduction: Cancer stem cells (CSCs), a group of tumor-initiating and tumor-maintaining cells, may be major players in the treatment resistance and recurrence distinctive of chordoma. Characterizing CSCs is crucial to better targeting this subpopulation. Methods: Using flow cytometry, six chordoma cell lines were evaluated for CSC composition. In vitro, cell lines were stained for B7H6, HER2, MICA-B, ULBP1, EGFR, and PD-L1 surface markers. Eighteen resected chordomas were stained using a multispectral immunofluorescence (mIF) antibody panel to identify CSCs in vivo. HALO software was used for quantitative CSC density and spatial analysis. Results: In vitro, chordoma CSCs express more B7H6, MICA-B, and ULBP1, assessed by percent positivity and mean fluorescence intensity (MFI), as compared to non-CSCs in all cell lines. PD- L1 percent positivity is increased by >20% in CSCs compared to non-CSCs in all cell lines except CH22. In vivo, CSCs comprise 1.39% of chordoma cells and most are PD-L1+ (75.18%). A spatial analysis suggests that chordoma CSCs cluster at an average distance of 71.51 mm (SD 73.40 mm) from stroma. Discussion: To our knowledge, this study is the first to identify individual chordoma CSCs and describe their surface phenotypes using in vitro and in vivo methods. PD-L1 is overexpressed on CSCs in chordoma human cell lines and operative tumor samples. Similarly, potential immunotherapeutic targets on CSCs, including B7H6, MICA-B, ULBP1, EGFR, and HER2 are overexpressed across cell lines. Targeting these markers may have a preferential role in combating CSCs, an aggressive subpopulation likely consequential to chordoma's high recurrence rate.

First-line pembrolizumab plus androgen deprivation therapy for locally advanced microsatellite instability-high prostate cancer in a patient with Muir-Torre syndrome: A case report.

The risks of development of colorectal and endometrial cancers in individuals with Lynch syndrome (LS) are well known and have been widely studied. In recent years, the potential association of other malignancies, including prostate cancer, with LS has been considered. Decision-making regarding screening for prostate cancer in the generalized population can be complicated; accounting for the possibility of a higher risk of cancer conferred by a potential genetic predisposition confounds the creation of salient guidelines even further. Although tissue-agnostic treatment approvals have been granted to several immune checkpoint inhibitors (ICIs) for their use in the treatment of subsets of patients whose tumors exhibit high levels of microsatellite instability or high tumor mutational burden, a paucity of data exists regarding the use of ICIs in the first line treatment of patients with locally advanced prostate cancer harboring these features. A significant reduction in tumor volume in response to the combination of immune checkpoint inhibition and androgen deprivation therapy is described in this report of a male with Muir-Torre syndrome who was found to have locally advanced adenocarcinoma of the prostate. While anecdotal, the anti-tumor activity of this combination of therapy is notable and calls attention to the importance of considering further investigation of the use of immune checkpoint blockade as a primary therapeutic option in patients with localized prostate cancer.

Immunology of Lynch Syndrome.

PURPOSE OF REVIEW: Patients with Lynch syndrome have a high probability of developing colorectal and other carcinomas. This review provides a comprehensive assessment of the immunologic aspects of Lynch syndrome pathogenesis and provides an overview of potential immune interventions for patients with Lynch syndrome polyps and Lynch syndrome-associated carcinomas. RECENT FINDINGS: Immunogenic properties of the majority of Lynch syndrome polyps and associated cancers include microsatellite instability leading to a high mutational burden and the development of novel frameshift peptides, i.e., neoantigens. In addition, patients with Lynch syndrome develop T cell responses in the periphery and in the tumor microenvironment (TME) to tumor-associated antigens, and a proinflammatory cytokine TME has also been identified. However, Lynch syndrome lesions also possess immunosuppressive entities such as alterations in MHC class I antigen presentation, TGFß receptor mutations, regulatory T cells, and upregulation of PD-L1 on tumor-associated lymphocytes. The rich immune microenvironment of Lynch syndrome polyps and associated carcinomas provides an opportunity to employ the spectrum of immune-mediating agents now available to induce and enhance host immune responses and/or to also reduce immunosuppressive entities. These agents can be employed in the so-called prevention trials for the treatment of patients with Lynch syndrome polyps and for trials in patients with Lynch syndrome-associated cancers.

Fast Clearance of the SARS-CoV-2 Virus in a Patient Undergoing Vaccine Immunotherapy for Metastatic Chordoma: A Case Report.

The emergence of the SARS-CoV-2 virus has been associated with perplexing clinical sequelae and phenomena that often have no clear link to the underlying infection. There is a wide spectrum of symptoms associated with infection, from minimal respiratory complaints to severe multi-organ failure, often resulting in death. Individuals with malignancies, particularly those whose treatments have left them immunocompromised or immunosuppressed, are among the patient populations thought to be at greater risk for more severe illness. A man with aggressive metastatic chordoma contracted the SARS-CoV-2 virus and was diagnosed with COVID-19 while undergoing intravenous brachyury vaccine immunotherapy. His disease course was remarkably mild, and the virus cleared rapidly. Despite a treatment delay of 3 months due to the COVID-19 pandemic, the patient's disease has been stable and tumor-related pain has significantly improved. This suggests not only an intact, functional immune system, but also one that appears to have been responsive to cancer treatment. It has been suggested that individuals undergoing treatment for metastatic cancer are at greater risk of severe SARS-CoV-2-related illnesses and complications. While immunosuppression may be a problem, particularly in those receiving conventional chemotherapeutic agents, it is possible that the non-specific effects of immune-enhancing therapies may confer some protection against SARS-CoV-2.

When a polyp is not a polyp: incidental finding of a sigmoid schwannoma at first colonoscopic screening.

Schwannomas, peripheral nerve sheath tumours arising from Schwann cells, are often associated with inherited disorders such as neurofibromatosis. Gastrointestinal schwannomas, while rare, have been reported in those without personal or family history of neurofibromatosis. Diagnoses of these lesions, however, typically follow evaluations prompted by symptomatic presentations associated with abdominal pain, rectal bleeding, change in bowel habits or positive results on faecal occult blood tests performed for colorectal cancer screening. Further, management of these predominantly benign lesions commonly incorporates surgical resection. We present the case of a sigmoid schwannoma found in an asymptomatic individual on first screening colonoscopy and treated with complete endoscopic polypectomy with anticipated surveillance colonoscopy.

NOD2 mutations affect muramyl dipeptide stimulation of human B lymphocytes and interact with other IBD-associated genes.

BACKGROUND: Genetic and functional studies have associated variants in the NOD2/CARD15 gene with Crohn's disease. AIMS: This study aims to replicate the association of three common NOD2 mutations with Crohn's disease, study its effect on NOD2 expression in B cells and its interaction with other IBD-associated genes. METHODS: A total of 294 IBD patients (179 familial IBD, 115 sporadic IBD) and 298 unrelated healthy controls were from central Pennsylvania. NOD2 mutations were analyzed by primer-specific amplification, PCR based-RFLP, and validated with the ABI SNPlexM genotyping system. Gene-gene interaction was studied using a statistical model for epistasis analysis. RESULTS: Three common NOD2 mutations are associated with Crohn's disease (p=5.08×10(-7), 1.67×10(-6), and 1.87×10(-2) for 1007fs, R720W, and G908R, respectively), but not with ulcerative colitis (p=0.1046, 0.1269, and 0.8929, respectively). For IBD overall, 1007finsC (p=4.4×10(-5)) and R720W (p=9.24×10(-5)) were associated with IBD, but not G908R (p=0.1198). We revealed significant interactions of NOD2 with other IBD susceptibility genes IL23R, DLG5, and OCTN1. We discovered that NOD2 was expressed in both normal human peripheral blood B cells and in EBV-transformed B cell lines. Moreover, we further demonstrated that muramyl dipeptide (MDP) stimulation of B lymphocytes up-regulated expression of NF-κB-p50 mRNA. CONCLUSION: NOD2 is expressed in peripheral B cells, and the up-regulation of NOD2 expression by MDP was significantly impaired by NOD2 mutations. The finding suggests a possible role of NOD2 in the immunological response in IBD pathogenesis.

Isolated pediatric pancreatic transection secondary to ocean-related trauma.

CONTEXT: Isolated pancreatic transection is a rare but well-recognized complication following blunt trauma of the abdomen. Diagnosis at presentation may be difficult and delayed due to subtle initial symptoms and evolving nature of the injury. CASE REPORT: We describe an isolated complete pancreatic transection in a 14-year-old female secondary to a previously unreported and highly unusual mechanism (being tossed by a wave). Diagnosis was obtained by computed tomography scan 24 hours following initial trauma. She was managed operatively with an open distal pancreatectomy with splenic preservation and no subsequent complications. CONCLUSIONS: The force sustained from the blunt abdominal trauma of being tossed by a wave can be significant. The management of pancreatic injuries in children, particularly in the context of ductal transection, is controversial. Timely recognition and management is critical to optimal outcomes. Early operative intervention may help to avoid complications such as abscess or pseudocyst formation.

NKX2-3 variant rs11190140 is associated with IBD and alters binding of NFAT.

NKX2-3 SNP rs11190140 is associated with inflammatory bowel disease (IBD). The T allele is over-transmitted in IBD and the C allele represents a potential CpG methylation site. We hypothesize that genetic variation and/or methylation of SNP rs11190140 may play a role in NKX2-3 gene expression by affecting transcription factor binding. We studied 233 IBD cases and 250 unrelated healthy individuals from an IBD population from central Pennsylvania and performed genotype analyses of the genetic variation and methylation status analysis using PCR-based RFLP. For transcription factor binding, nuclear extracts from human B cells were incubated with biotin-labeled oligonucleotide sequences of the NKX2-3 promoter region containing the genetic variation of T, non-methylated C or methylated C at rs11190140, followed by biotin pull-down and Western blot analysis for transcription factors SP1, NFAT1, NF-κB, and ETS-1. In case-control analysis, the genetic variation was significantly associated with IBD (OR=0.503, 95% CI=0.330-0.764, p<0.001). Methylation status analyses revealed that the C allele is subject to modification by DNA methylation. transcription factor binding assay indicated distinct differential binding of NFAT1 to the NKX2-3 promoter sequence, with higher binding to those with non-methylated and methylated C than to T. The binding of NFAT1 to the NKX2-3 promoter region with rs1190140 was confirmed by ChIP assay. We speculate that the rs11190140 may regulate NKX2-3 expression and have a role in IBD pathogenesis.

Prostate apoptosis response protein 4 sensitizes human colon cancer cells to chemotherapeutic 5-FU through mediation of an NF kappaB and microRNA network.

BACKGROUND: Diminished expression or activity of prostate apoptosis response protein 4 (Par-4) has been demonstrated in a number of cancers, although reports on Par-4 expression during colon cancer progression are lacking. An understanding of the molecular events in conjunction with the genetic networks affected by Par-4 is warranted. RESULTS: Colon cancer specimens derived from patients have significantly diminished expression of Par-4 mRNA relative to paired normal colon. Hence, the functional consequences of reintroducing Par-4 into HT29 colon cancer cells were assessed. Overexpression augmented the interaction of Par-4 with NF kappaB in the cytosol but not nucleus, and facilitated apoptosis in the presence of 5-fluorouracil (5-FU). Analogous findings were obtained when AKT1 pro-survival signaling was inhibited. Transcriptome profiling identified approximately 700 genes differentially regulated by Par-4 overexpression in HT29 cells. Nearly all Par-4-regulated genes were shown by promoter analysis to contain cis-binding sequences for NF kappaB, and meta-analysis of patient expression data revealed that one-third of these genes exist as a recurrent co-regulated network in colon cancer specimens. Sets of genes involved in programmed cell death, cell cycle regulation and interestingly the microRNA pathway were found overrepresented in the network. Noteworthy, Par-4 overexpression decreased NF kappaB occupancy at the promoter of one particular network gene DROSHA, encoding a microRNA processing enzyme. The resulting down-regulation of DROSHA was associated with expression changes in a cohort of microRNAs. Many of these microRNAs are predicted to target mRNAs encoding proteins with apoptosis-related functions. Western and functional analyses were employed to validate several predictions. For instance, miR-34a up-regulation corresponded with a down-regulation of BCL2 protein. Treating Par-4-overexpressing HT29 cells with a miR-34a antagomir functionally reversed both BCL2 down-regulation and apoptosis by 5-FU. Conversely, bypassing Par-4 overexpression by direct knockdown of DROSHA expression in native HT29 cells increased miR-34a expression and 5-FU sensitivity. CONCLUSION: Our findings suggest that the initiation of apoptotic sensitivity in colon cancer cells can be mediated by Par-4 binding to NF kappaB in the cytoplasm with consequential changes in the expression of microRNA pathway components.

Primary cell lines: false representation or model system? a comparison of four human colorectal tumors and their coordinately established cell lines.

Cultured cell lines have played an integral role in the study of tumor biology since the early 1900's. The purpose of this study is to evaluate colorectal cancer (CRC) cell lines with respect to progenitor tumors and assess whether these cells accurately and reliably represent the cancers from which they are derived. Primary cancer cell lines were derived from fresh CRC tissue. Tumorigenicity of cell lines was assessed by subcutaneous injection of cells into athymic mice and calculation of tumor volume after 3 weeks. DNA ploidy was evaluated by flow cytometry. Invasive ability of the lines was tested with the MATRIGEL invasion assay at 24 or 48 hours. Cells were assessed for the presence of Kirsten-Ras (K-Ras), p-53, deleted in colon cancer (DCC), and Src. Protein profiling of cells and tissue was performed by surface enhanced laser desorption/ionization-time of flight/mass spectroscopy. microRNA expression in cell and tumor tissue samples was evaluated by FlexmiR MicroRNA Assays. Four cell lines were generated from tumor tissue from patients with CRC and confirmed to be tumorigenic (mean tumor volume 158.46 mm(3)). Two cell lines were noted to be diploid; two were aneuploid. All cell lines invaded the MATRIGEL starting as early as 24 hours. K-Ras, p53, DCC, and Src expression were markedly different between cell lines and corresponding tissue. Protein profiling yielded weak-to-moderate correlations between cell samples and respective tissues of origin. Weak-to-moderate tau correlations for levels of expression of human microRNAs were found between cells and respective tissue samples for each of the four pairings. Although our primary CRC cell lines vary in their expression of several tumor markers and known microRNAs from their respective progenitor tumor tissue, they do not statistically differ in overall profiles. Characteristics are retained that deem these cell lines appropriate models of disease; however, data acquired through the use of cell culture may not always be a completely reliable representation of tumor activity in vivo.

Genes regulated by Nkx2-3 in sporadic and inflammatory bowel disease-associated colorectal cancer cell lines.

BACKGROUND: Nkx2-3 has been reported to be up-regulated in B cell lines and intestinal tissues from Crohn's disease patients and down-regulated in colorectal cancer. AIMS: The purpose of the current study is to determine genes regulated by Nkx2-3 in sporadic (CRS61) and inflammatory bowel disease-associated (CRS4) colorectal cancer cell lines. METHODS: Small interfering RNA-mediated knockdown of Nkx2-3 in both cell lines was generated and high-density cDNA microarrays representing over 25,000 genes were performed. Microarray results were validated by RT-PCR and immunofluorescence. Pathway analysis was used to identify gene networks associated with Nkx2-3 knockdown in these cell lines. RESULTS: A total of 1,677 genes were regulated by Nkx2-3 in CRS4 cells; 1,375 genes were regulated by Nkx2-3 in CRS61 cells. Among those genes regulated by Nkx2-3, 254 genes were similarly regulated by Nkx2-3 knockdown in both cell lines; 159 genes were differentially regulated by Nkx2-3 knockdown between the two lines. Genes regulated by Nkx2-3 were grouped primarily within the following two functional categories: (1) immune and inflammatory response; and (2) cell proliferation, growth, and oncogenesis. Among the genes with similarly changed expression in the two cell lines, the top affected pathways included antigen presentation and cell-cell signaling. Among the genes with differentially changed expression between the two cell lines, ingenuity pathway analysis indicated that the top affected pathway included genes directly involved in Wnt signaling. CONCLUSIONS: Nkx2-3 may contribute to the pathogenesis of IBD-associated CRC and sporadic CRC by regulating the Wnt signaling pathway.

Tumor necrosis factor alpha induces p53 up-regulated modulator of apoptosis expression in colorectal cancer cell lines.

PURPOSE: Inflammatory bowel disease (IBD)-associated colorectal carcinogenesis involves dysregulation of multiple cellular pathways, including p53 signaling and cytokine action. The purpose of the current study was to evaluate the effects of tumor necrosis factor alpha (TNF-alpha) on p53 and p53 up-regulated modulator of apoptosis (PUMA), a downstream effector of p53 in the apoptotic pathway in colorectal cancer cells. METHODS: The cell lines HT29 (which express mutant p53) and HCT116 (which express wild-type p53) were treated with TNF-alpha (0, 50, 100, or 500 ng/mL) for 1, 12, 24, or 48 hours. Protein expression and subcellular localization of p53 and PUMA were determined by immunoblot and immunofluorescence. Changes in p53 and PUMA mRNA expression were determined by quantitative real time polymerase chain reaction. RESULTS: Nuclear p53 expression was increased in TNF-alpha-treated HT29 cells; in contrast, expression was decreased or minimally changed in TNF-alpha-treated HCT116 cells, as determined by immunoblot and immunofluorescence. At 24 hours, p53 mRNA transcript levels were minimally increased in HT29 cells, whereas PUMA increased 34-fold. CONCLUSIONS: TNF-alpha increased nuclear p53 expression in HT29 cells, which express p53 mutation, but not in HCT116 cells, which are wild type for p53. In addition, TNF-alpha markedly up-regulated PUMA mRNA levels in HT29 cells. Our findings suggest that TNF-alpha may be a factor in carcinogenesis in IBD in cells carrying a p53 mutation.

Parastomal hernia repair: a single center experience.

BACKGROUND/OBJECTIVES: Despite multiple options for operative repair of parastomal hernia, results are frequently disappointing. We review our experience with parastomal hernia repair. METHODS: A retrospective chart review was performed on all patients with parastomal hernia who underwent LAP or open repair at our institution between 1999 and 2006. Information collected included demographics, indication for stoma creation, operative time, length of stay, postoperative complications, and recurrence. RESULTS: Twenty-five patients who underwent laparoscopic or open parastomal hernia repair were identified. Laparoscopic repair was attempted on 12 patients and successfully completed on 11. Thirteen patients underwent open repair. Operative time was 172+/-10.0 minutes for laparoscopic and 137+/-19.1 minutes for open cases (P=0.14). Lengths of stay were 3.1+/-0.4 days (laparoscopic) and 5.1+/-0.8 days (open), P=0.05. Immediate postoperative complications occurred in 4 laparoscopic patients (33.3%) and 2 open patients (15.4%), P=0.38. Parastomal hernia recurred in 4 laparoscopic patients (33.3%) and 7 open patients (53.8%) after 13.9+/-4.5 months and 21.4+/-4.3 months, respectively, P=0.43. CONCLUSION: Laparoscopic modified Sugarbaker technique in the repair of parastomal hernia affords an alternative to open repair for treating parastomal hernia.

Regulation of hippocampal parkin protein by corticosteroids.

Parkin is a protein that when mutated leads to an inherited form of Parkinson's disease. Under normal conditions, this molecule has multiple functions in different cell types, including protein degradation and tumor suppression. To understand the relationship between parkin and circulating corticosteroid hormones, we studied the long-term depletion of corticosterone due to bilateral adrenalectomy in rats. We show that adrenalectomy deletes the expected expression of nuclear parkin in hippocampal neurons. Notably, the effect of adrenalectomy on parkin was prevented by corticosterone hormone replacement therapy. This finding suggests that adrenal hormones may be critical in sustaining parkin ubiquitinating activity in the rat hippocampus.

BAX protein-immunoreactivity in midbrain neurons of Parkinson's disease patients.

Apoptosis has been implicated in the pathophysiology of Parkinson's disease (PD). Components of signaling pathways that initiate cell death are highly concentrated in vulnerable substantia nigra (SN) neurons and may therefore contribute to the relentless demise of dopamine cells. Here, we report the distribution and organizational pattern of the pro-apoptotic protein BAX in the parkinsonian brain. Coronal sections (60 microm) of SN material from control and PD patients showed identical expression of BAX-immunoreactivity (IR) in all cases examined. Neurons positive for BAX-IR exhibited a discrete cytoplasmic and dendritic labeling that was conspicuously interspersed with previously unrecognized axonal spheroid-like inclusions. Direct comparisons revealed a difference in the aggregation of BAX-rich inclusions, with the parkinsonian brain containing more SN inclusions than control cases. BAX expression by midbrain neurons was confirmed by immunoblot analysis on SN extracts showing a specific band of approximately 21kDa, which is consistent with the known molecular weight of native BAX. These results suggest that apoptosis or programmed cell death may play an indirect role in idiopathic PD.