Surgical management of pancreatic ductal adenocarcinoma: a narrative review.

Background and Objective: Pancreatic ductal adenocarcinoma (PDAC) is the third-leading cause of cancer-related death in the United States and is projected to become the second-leading cause of cancer-related death by 2030. Despite advances in systemic and radiation therapy, for patients with surgically resectable PDAC, complete surgical resection is the only potentially curative treatment option. The conduct of a safe, technically excellent pancreatectomy is essential to achieve optimal perioperative outcomes and long-term survival. In this narrative review, evidence from large, well-executed studies and clinical trials examining the technical aspects of pancreatectomy is reviewed. Methods: A search was conducted in PubMed, Medline, and Cochrane Review databases to identify English-language randomized clinical trials, meta-analyses, and systematic reviews assessing surgical aspects of pancreatectomy for PDAC published between 2010 to 2023. Key Content and Findings: We identified retrospective and prospective studies evaluating the technical aspects of surgery for PDAC. In this review, we evaluate data on surgical techniques of pancreatectomy for PDAC, including the role of minimally invasive techniques, extent of lymphadenectomy, reconstruction options after pancreatoduodenectomy, and the role of surgical drainage. Conclusions: Surgical resection has a critical role in the treatment of operable PDAC. While pancreatic cancer surgery is an active area of research, conducting a technically excellent surgical resection maintains paramount importance for both oncological and perioperative outcomes. In this review, we summarize the latest evidence on surgical technique for operable PDAC.

Methodological Considerations on COVID-19 Mortality in Cancer Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: Patients with cancer are at risk for severe COVID-19. Previous studies examining mortality in cancer patients with COVID-19 have produced inconclusive results. Several published meta-analyses have aimed to estimate this association; however, because of methodological limitations in study selection and data aggregation, these studies do not reliably estimate the independent association between cancer and COVID-19 mortality. We conducted this systematic review and meta-analysis to determine whether cancer is an independent risk factor for COVID-19 mortality. METHODS: A literature search was performed in PubMed to identify studies that compared COVID-19 mortality in adult patients with and without cancer. Selection criteria included polymerase chain reaction-confirmed COVID-19, multivariate adjustment and/or matching for mortality risk estimates, and inclusion of hospitalized noncancer controls. Adjusted odds ratios and/or hazard ratios for mortality based on cancer status were extracted. Odds ratio and hazard ratio estimates were pooled using a random effects model. RESULTS: The analysis included 42 studies comprising 129 840 patients: 8612 cancer patients and 121 228 noncancer patients. Of these studies, 18 showed a null difference in survival between cancer and noncancer patients with COVID-19, and 24 studies showed statistically significantly worse survival in cancer patients with COVID-19. Meta-analysis revealed an increased risk of mortality in patients with cancer compared with noncancer patients with COVID-19 (odds ratio = 1.93, 95% confidence interval = 1.55 to 2.41; hazard ratio = 1.54, 95% confidence interval = 1.29 to 1.84). CONCLUSION: We conclude that cancer is an independent risk factor for mortality in unvaccinated patients admitted for or diagnosed with COVID-19 during hospitalization.

Evaluation of Elafin as a Prognostic Biomarker in Acute Graft-versus-Host Disease.

Acute graft-versus-host disease (GVHD) is a major cause of mortality in patients undergoing hematopoietic cell transplantation (HCT) for hematologic malignancies. The skin is the most commonly involved organ in GVHD. Elafin, a protease inhibitor overexpressed in inflamed epidermis, was previously identified as a diagnostic biomarker of skin GVHD; however, this finding was restricted to a subset of patients with isolated skin GVHD. The main driver of nonrelapse mortality (NRM) in HCT recipients is gastrointestinal (GI) GVHD. Two biomarkers, Regenerating islet-derived 3a (REG3α) and Suppressor of tumorigenesis 2 (ST2), have been validated as biomarkers of GI GVHD that predict long-term outcomes in patients treated for GVHD. We undertook this study to determine the utility of elafin as a prognostic biomarker in the general population of acute GVHD patients in whom GVHD may develop in multiple organs. We analyzed serum elafin concentrations as a predictive biomarker of acute GVHD outcomes and compared it with ST2 and REG3α in a large group of patients treated at multiple centers. A total of 526 patients from the Mount Sinai Acute GVHD International Consortium (MAGIC) who had received corticosteroid treatment for skin GVHD and who had not been previously studied were analyzed. Serum concentrations of elafin, ST2, and REG3α were measured by ELISA in all patients. The patients were divided at random into equal training and validation sets, and a competing-risk regression model was developed to model 6-month NRM using elafin concentration in the training set. Additional models were developed using concentrations of ST2 and REG3α or the combination of all 3 biomarkers as predictors. Receiver operating characteristic (ROC) curves were constructed using the validation set to evaluate the predictive accuracy of each model and to stratify patients into high- and low-risk biomarker groups. The cumulative incidence of 6-month NRM, overall survival (OS), and 4-week treatment response were compared between the risk groups. Unexpectedly, patients in the low-risk elafin group demonstrated a higher incidence of 6-month NRM, although the difference was not statistically significant (17% versus 11%; P = .19). OS at 6 months (68% versus 68%; P > .99) and 4-week response (78% versus 78%; P = .98) were similar in the low-risk and high-risk elafin groups. The area under the ROC curve (AUC) was 0.55 for elafin and 0.75 for the combination of ST2 and REG3α. The addition of elafin to the other 2 biomarkers did not improve the AUC. Our data indicate that serum elafin concentrations measured at the initiation of systemic treatment for acute GVHD did not predict 6-month NRM, OS, or treatment response in a multicenter population of patients treated systemically for acute GVHD. As seen in previous studies, serum concentrations of the GI GVHD biomarkers ST2 and REG3α were significant predictors of NRM, and the addition of elafin levels did not improve their accuracy. These results underscore the importance of GI disease in driving NRM in patients who develop acute GVHD.

High expression of maternal embryonic leucine-zipper kinase (MELK) impacts clinical outcomes in patients with ovarian cancer and its inhibition suppresses ovarian cancer cells growth ex vivo.

OBJECTIVE: Maternal embryonic leucine zipper kinase (MELK) is receiving an attention as a therapeutic target in various types of cancers. In this study, we aimed to evaluate the prognostic significance of MELK expression in ovarian cancer using clinical samples, and assessed the efficacy of a small molecule MELK inhibitor, OTS167, using patient-derived ovarian cancer cells as well as cell lines. METHODS: Expression levels of MELK in 11 ovarian cancer cell lines were confirmed by western blotting. Inhibitory concentration of OTS167 was determined by colorimetric assay. MELK messenger RNA (mRNA) expression was evaluated in 228 ovarian cancer patients by quantitative polymerase chain reaction. Growth inhibition of OTS167 was also evaluated using freshly-isolated primary ovarian cancer cells including spheroid formation condition. RESULTS: MELK mRNA expression was significantly higher in ovarian cancer than in normal ovaries (p<0.001), and high MELK mRNA expression was observed in patients with advanced stage, positive ascites cytology and residual tumor size. Patients with high MELK mRNA expression showed shorter progression-free survival (p=0.001). Expression of MELK was also confirmed in 10 of 11 ovarian cancer cell lines tested, and the half maximal inhibitory concentration of MELK inhibitor, OTS167, ranged from 9.3 to 60 nM. Additionally, OTS167 showed significant growth inhibitory effect against patient-derived ovarian cancer cells, regardless of their tumor locations, histologic subtypes and stages. CONCLUSIONS: We demonstrated MELK as both a prognostic marker and a therapeutic target for ovarian cancer using clinical ovarian cancer samples. MELK inhibition by OTS167 may be an effective approach to treat ovarian cancer patients.

WHSC1 monomethylates histone H1 and induces stem-cell like features in squamous cell carcinoma of the head and neck.

Squamous cell carcinoma of the head and neck (SCCHN) is a malignancy with poor outcomes, thus novel therapies are urgently needed. We recently showed that WHSC1 is necessary for the viability of SCCHN cells through H3K36 di-methylation. Here, we report the identification of its novel substrate, histone H1, and that WHSC1-mediated H1.4K85 mono-methylation may enhance stemness features in SCCHN cells. To identify proteins interacting with WHSC1 in SCCHN cells, WHSC1 immunoprecipitation and mass spectrometry identified H1 as a WHSC1-interacting candidate. In vitro methyltransferase assays showed that WHSC1 mono-methylates H1 at K85. We generated an H1K85 mono-methylation-specific antibody and confirmed that this methylation occurs in vivo. Sphere formation assays using SCC-35 cells stably expressing either wild-type (FLAG-H1.4-WT) or mutated (FLAG-H1.4K85A) vector with lysine 85 to alanine substitution which is not methylated, indicated a higher number of spheres in SCC-35 cells expressing the wild type than those with the mutant vector. SCC-35 cells expressing the wild type H1.4 proliferated faster than those expressing the mutated vector. RNA sequencing, RT-PCR and Western blotting of the FLAG-H1.4-WT or FLAG-H1.4K85A SCC-35 cells revealed that OCT4 levels were higher in wild type compared to mutant cells. These results were reproduced in SCC-35 cells genetically modified with CRISPR to express H1.4K85R. Chromatin immunoprecipitation showed that FLAG-H1.4K85A had decreased occupancy in the OCT4 gene compared to FLAG-H1.4-WT. This study supports that WHSC1 mono-methylates H1.4 at K85, it induces transcriptional activation of OCT4 and stemness features in SCCHN cells, providing rationale to target H1.4K85 mono-methylation through WHSC1 in SCCHN.

A whole-tissue RNA-seq toolkit for organism-wide studies of gene expression with PME-seq.

The immune system operates at the scale of the whole organism in mammals. We currently lack experimental approaches to systematically track and study organism-wide molecular processes in mice. Here we describe an integrated toolkit for measuring gene expression in whole tissues, 3-prime mRNA extension sequencing, that is applicable to most mouse organs and any mouse model of interest. Further, the methods of RNA-seq described in this protocol are broadly applicable to other sample types beyond whole organs, such as tissue samples or isolated cell populations. We report procedures to collect, store and lyse a dozen organ types using conditions compatible with the extraction of high-quality RNA. In addition, we detail protocols to perform high-throughput and low-cost RNA extraction and sequencing, as well as downstream data analysis. The protocol takes 5 d to process 384 mouse organs from collecting tissues to obtaining raw sequencing data, with additional time required for data analysis and mining. The protocol is accessible to individuals with basic skills in (i) mouse perfusion and dissection for sample collection and (ii) computation using Unix and R for data analysis. Overall, the methods presented here fill a gap in our toolbox for studying organism-wide processes in immunology and physiology.

Methylation and transcription patterns are distinct in IDH mutant gliomas compared to other IDH mutant cancers.

Mutations in isocitrate dehydrogenases 1 and 2 (IDHmut) are present in a variety of cancers, including glioma, acute myeloid leukemia (AML), melanoma, and cholangiocarcinoma. These mutations promote hypermethylation, yet it is only a favorable prognostic marker in glioma, for reasons that are unclear. We hypothesized that the patterns of DNA methylation, and transcriptome profiles, would vary among IDHmut cancers, especially gliomas. Using Illumina 450K and RNA-Seq data from The Cancer Genome Atlas, we show that of 365,092 analyzed CpG sites, 70,591 (19%) were hypermethylated in IDHmut gliomas compared to wild-type (IDHwt) gliomas, and only 3%, 2%, and 4% of CpG sites were hypermethylated in IDHmut AML, melanoma, and cholangiocarcinoma, relative to each of their IDHwt counterparts. Transcriptome differences showed pro-malignant genes that appear to be unique to IDHmut gliomas. However, genes involved in differentiation and immune response were suppressed in all IDHmut cancers. Additionally, IDHmut caused a greater degree of hypermethylation in undifferentiated neural progenitor cells than in mature astrocytes. These data suggest that the extent and targets of IDHmut-induced genomic hypermethylation vary greatly according to the cellular context and may help explain why IDHmut is only a favorable prognostic marker in gliomas.

TCR sequencing analysis of cancer tissues and tumor draining lymph nodes in colorectal cancer patients.

Tumor draining lymph nodes (TDLNs) are located in the routes of lymphatic drainage from a primary tumor and have the highest risk of metastasis in various types of solid tumors. TDLNs are also considered as a tissue to activate the antitumor immunity, where antigen-specific effector T cells are generated. However, T cell receptor (TCR) repertoires in TDLNs have not been well characterized. We collected 23 colorectal cancer tumors with 203 lymph nodes with/without metastatic cancer cells (67 were metastasis-positive and the remaining 136 were metastasis-negative) and performed TCR sequencing. Metastasis-positive TDLNs showed a significantly lower TCR diversity and shared TCR clonotypes more frequently with primary tumor tissues compared to metastasis-negative TDLNs. Principal component analysis indicated that TDLNs with metastasis showed similar TCR repertoires. These findings suggest that cancer-reactive T cell clones could be enriched in the metastasis-positive TDLNs.

The era of immunogenomics/immunopharmacogenomics.

Although germline alterations and somatic mutations in disease cells have been extensively analyzed, molecular changes in immune cells associated with disease conditions have not been characterized in depth. It is clear that our immune system has a critical role in various biological and pathological conditions, such as infectious diseases, autoimmune diseases, drug-induced skin and liver toxicity, food allergy, and rejection of transplanted organs. The recent development of cancer immunotherapies, particularly drugs modulating the immune checkpoint molecules, has clearly demonstrated the importance of host immune cells in cancer treatments. However, the molecular mechanisms by which these new therapies kill tumor cells are still not fully understood. In this regard, we have begun to explore the role of newly developed tools such as next-generation sequencing in the genetic characterization of both cancer cells and host immune cells, a field that is called immunogenomics/ immunopharmacogenomics. This new field has enormous potential to help us better understand changes in our immune system during the course of various disease conditions. Here we report the potential of deep sequencing of T-cell and B-cell receptors in capturing the molecular contribution of the immune system, which we believe plays critical roles in the pathogenesis of various human diseases.

Effective screening of T cells recognizing neoantigens and construction of T-cell receptor-engineered T cells.

Neoantigens are the main targets of tumor-specific T cells reactivated by immune checkpoint-blocking antibodies or when using tumor-infiltrating T cells for adoptive therapy. While cancers often accumulate hundreds of mutations and harbor several immunogenic neoantigens, the repertoire of mutation-specific T cells in patients might be restricted. To bypass suboptimal conditions, which impede the reactivation of existing T cells or the priming of neoantigen-specific T cells in a patient, we employ T cells of healthy donors with an overlapping HLA repertoire to target cancer neoantigens. In this study, we focus on streamlining the process of in vitro-induction of neoantigen-specific T cells and isolating their T cell receptors (TCRs) to establish a time-efficient protocol that will allow the patient to benefit from subsequent therapy. We first optimized the priming of T cells to omit multiple restimulations and extended culturing. Neoantigen-specific T cells were enriched using specific dextramers and next-generation sequencing was applied to determine the TCR repertoire. This allowed us to circumvent the laborious process of expanding T cell clones. Using this protocol, we successfully identified HLA-A-restricted TCRs specific for neoantigens found in an esophageal cancer cell line (TE-8) and a primary ovarian cancer. To verify TCR specificity, we generated TCR-engineered T cells and confirmed recognition of the tumor-derived neoantigens. Our results also emphasize the importance of neoepitope selection in order to avoid cross-reactivity to corresponding wild-type peptide sequences. In conclusion, we established a 2-week protocol for generating and identifying neoantigen-specific TCRs from third-party donors making this strategy applicable for clinical use.

Characterization of the T-Cell Receptor Repertoire and Immune Microenvironment in Patients with Locoregionally Advanced Squamous Cell Carcinoma of the Head and Neck.

Purpose: Squamous cell carcinoma of the head and neck (SCCHN) is a lethal cancer with a suboptimal 5-year overall survival of approximately 50% with surgery and/or definitive chemoradiotherapy. Novel treatments are thus urgently awaited. Immunotherapy with checkpoint blockade has emerged as a promising option for patients with recurrent/metastatic SCCHN; however, it has not been investigated in the curative-intent setting yet. The purpose of this study was to investigate the T-cell receptor repertoire and the tumor microenvironment in tumor tissues of SCCHN patients with locoregionally advanced disease.Experimental Design: We performed T-cell receptor sequencing of tumor tissues from 44 patients with locoregionally advanced SCCHN prior to treatment with definitive chemoradiotherapy and correlated the T-cell clonality and the mRNA expression levels of immune-related genes with clinicopathologic parameters.Results: Clonal expansion of T cells was significantly higher in human papilloma virus (HPV)-negative compared with HPV-positive tumors, signifying more robust antigen presentation in HPV-negative tumors. The latter was supported by the higher percentage of HPV-negative tumors expressing HLA-A protein compared with HPV-positive tumors (P = 0.049). Higher GRZB levels correlated significantly with longer recurrence-free survival (log-rank, P = 0.003) independent of tumor size, nodal stage, and HPV status.Conclusions: Our findings support clonal expansion of T cells in SCCHN patients with locoregionally advanced disease and imply differences in the antigen presentation capacity between HPV-negative and HPV-positive tumors. Elevated GRZB mRNA levels may also serve as a favorable and independent predictor of outcome in SCCHN patients treated with chemoradiotherapy. These data provide rationale for the introduction of immunotherapeutic approaches in the curative-intent setting. Clin Cancer Res; 23(16); 4897-907. ©2017 AACR.

Integrated analysis of somatic mutations and immune microenvironment in malignant pleural mesothelioma.

To investigate the link between the genomic landscape of cancer cells and immune microenvironment in tumor tissues, we characterized somatic mutations and tumor-infiltrating lymphocytes (TILs) in malignant pleural mesothelioma (MPM), including mutation/neoantigen load, spatial heterogeneity of somatic mutations of cancer cells and TILs (T-cell receptor ß (TCRß) repertoire), and expression profiles of immune-related genes using specimens of three different tumor sites (anterior, posterior, and diaphragm) obtained from six MPM patients. Integrated analysis identified the distinct patterns of somatic mutations and the immune microenvironment signatures both intratumorally and interindividually. MPM cases showed intratumoral heterogeneity in somatic mutations with unique TCRß clonotypes of TILs that were restricted to each tumor site, suggesting the presence of a neoantigen-related immune response. Correlation analyses showed that higher neoantigen load was significantly correlated with stronger clonal expansion of TILs (p = 0.048) and a higher expression level of an immune-associated cytolytic factor (PRF1 (p = 0.0041) in tumor tissues), suggesting that high neoantigen loads in tumor cells might promote expansion of functional tumor-specific T cells in the tumor bed. Our results collectively indicate that MPM tumors constitute a diverse heterogeneity in both the genomic landscape and immune microenvironment, and that mutation/neoantigen load may affect the immune microenvironment in MPM tissues.

TOPK (T-LAK cell-originated protein kinase) inhibitor exhibits growth suppressive effect on small cell lung cancer.

T-lymphokine-activated killer cell-originated protein kinase (TOPK) plays critical roles in cancer cell proliferation as well as maintenance of cancer stem cells (CSC). Small cell lung cancer (SCLC) has highly aggressive phenotype, reveals early spread to distant sites, and results in dismal prognosis with little effective treatment. In this study, we demonstrate that TOPK expression was highly upregulated in both SCLC cell lines and primary tumors. Similar to siRNA-mediated TOPK knockdown effects, treatment with a potent TOPK inhibitor, OTS514, effectively suppressed growth of SCLC cell lines (IC50 ; 0.4-42.6 nM) and led to their apoptotic cell death. TOPK inhibition caused cell morphologic changes in SCLC cells, elongation of intercellular bridges caused by cytokinesis defects or neuronal protrusions induced by neuronal differentiation in a subset of CSC-like SCLC cells. Treatment with OTS514 suppressed forkhead box protein M1 (FOXM1) activity, which was involved in stemness of CSC. Furthermore, OTS514 treatment reduced CD90-positive SCLC cells and showed higher cytotoxic effect against lung sphere-derived CSC-like SCLC cells. Collectively, our results suggest that targeting TOPK is a promising approach for SCLC therapy.

WHSC1L1-mediated EGFR mono-methylation enhances the cytoplasmic and nuclear oncogenic activity of EGFR in head and neck cancer.

While multiple post-translational modifications have been reported to regulate the function of epidermal growth factor receptor (EGFR), the effect of protein methylation on its function has not been well characterized. In this study, we show that WHSC1L1 mono-methylates lysine 721 in the tyrosine kinase domain of EGFR, and that this methylation leads to enhanced activation of its downstream ERK cascade without EGF stimulation. We also show that EGFR K721 mono-methylation not only affects the function of cytoplasmic EGFR, but also that of nuclear EGFR. WHSC1L1-mediated methylation of EGFR in the nucleus enhanced its interaction with PCNA in squamous cell carcinoma of the head and neck (SCCHN) cells and resulted in enhanced DNA synthesis and cell cycle progression. Overall, our study demonstrates the multifaceted oncogenic function of the protein lysine methyltransferase WHSC1L1 in SCCHN, which is mediated through direct non-histone methylation of the EGFR protein with effects both in its cytoplasmic and nuclear functions.

Intratumoral expression levels of PD-L1, GZMA, and HLA-A along with oligoclonal T cell expansion associate with response to nivolumab in metastatic melanoma.

Immune checkpoint inhibitors blocking the interaction between programmed death-1 (PD-1) and PD-1 ligand-1 (PD-L1) are revolutionizing the cancer immunotherapies with durable clinical responses. Although high expression of PD-L1 in tumor tissues has been implicated to correlate with the better response to the anti-PD-1 therapies, this association has been controversial. In this study, to characterize immune microenvironment in tumors, we examined mRNA levels of immune-related genes and characterized T cell repertoire in the tumors of 13 melanoma patients before and after nivolumab treatment. We found that, in addition to the PD-L1 (p = 0.03), expression levels of PD-1 ligand-2 (PD-L2), granzyme A (GZMA) and human leukocyte antigen-A (HLA-A) in the pre-treatment tumors were significantly higher (p = 0.04, p = 0.01 and p = 0.006, respectively) in responders (n = 5) than in non-responders (n = 8). With nivolumab treatment, tumors in responders exhibited a substantial increase of CD8, GZMA and perforin 1 (PRF1) expression levels as well as increased ratio of TBX21/GATA3, suggesting dominancy of helper T cell type 1 (Th1) response to type 2 (Th2) response. T cell receptor ß (TCR-ß) repertoire analysis revealed oligoclonal expansion of tumor-infiltrating T lymphocytes (TILs) in the tumor tissues of the responders. Our findings suggest that melanoma harboring high PD-1 ligands (PD-L1 and PD-L2), GZMA and HLA-A expression may respond preferentially to nivolumab treatment, which can enhance Th1-skewed cellular immunity with oligoclonal expansion of TILs.

WHSC1L1 drives cell cycle progression through transcriptional regulation of CDC6 and CDK2 in squamous cell carcinoma of the head and neck.

Wolf-Hisrchhorn Syndrome Candidate 1-Like 1 (WHSC1L1) is a protein lysine methyltransferase that is recurrently amplified (8p11.23) in patients with squamous cell carcinoma of the head and neck (SCCHN). In this study, we investigated the oncogenic role of WHSC1L1 in SCCHN. Using immunohistochemistry on tissue microarrays of patients with locoregionally advanced SCCHN, we found that WHSC1L1 is significantly overexpressed in patients with SCCHN, and is associated with poor grade and heavy smoking history. Knockdown of WHSC1L1 expression resulted in significant growth suppression and reduction of H3K36 dimethylation (H3K36me2) in SCCHN cells. Chromatin immunoprecipitation analysis showed that WHSC1L1 and H3K36me2 are enriched in the gene bodies of the cell cycle-related genes CDC6 and CDK2, implying that WHSC1L1 directly regulates the transcription of these genes. According to the importance of CDC6 and CDK2 for G1 to S transition, WHSC1L1 knockdown induced strong G0/G1 arrest which was rescued by introduction of wild-type WHSC1L1 but not by that of enzyme-inactive WHSC1L1. Our results imply that WHSC1L1 and its product H3K36me2 are essential for the transition from G1 to S phase in SCCHN cells and that WHSC1L1 could serve as a rational target for anticancer drug development for patients with head and neck cancer.