Molecular classification and precision therapy of cancer: immune checkpoint inhibitors

Comprehensive pan-cancer analysis reveals that C5orf34 regulates the proliferation and mortality of lung cancer

The gene C5orf34 exhibits evolutionary conservation among mammals, and emerging evidence suggests its potential involvement in tumor development; however, comprehensive investigations of this gene are lacking. This study aims to elucidate the functional attributes and underlying mechanisms of C5orf34 in cancer. To evaluate its clinical predictive value, we conducted an analysis of the pan-cancerous expression, clinical data, mutation, and methylation data of C5orf34. Additionally, we investigated the correlation between C5orf34 and tumor mutant load (TMB), immune cell infiltration, and microsatellite instability (MSI) through relevant analyses. Furthermore, immunohistochemical (IHC) staining was employed to validate clinical samples, while knockdown and overexpression experiments and transcriptome RNA sequencing were utilized to examine the impact of C5orf34 on LUAD cells. According to our study, C5orf34 exhibits high expression levels in the majority of malignant tumors. The upregulation of C5orf34 is governed by DNA copy number alterations and methylation patterns, and it is closely associated with patients' survival prognosis and immune characteristics, thereby holding significant clinical implications. Furthermore, IHC staining analysis, cellular experiments, and transcriptome RNA sequencing have provided evidence supporting the role of C5orf34 in modulating the cell cycle to promote LUAD proliferation, migration, and invasion. This highlights its potential as a promising therapeutic target. The findings of this investigation suggest that C5orf34 may serve as a valuable biomarker for various tumor types and represent a potential target for immunotherapy, particularly in relation to the proliferation, migration, and apoptosis of LUAD cells.

Chordoma Genetic Aberrations and Targeted Therapies Panorama: A Systematic Literature Review

Background: Chordomas pose a challenge in treatment due to their local invasiveness, high recurrence, and potential lethality. Despite being slow-growing and rarely metastasizing, these tumors often resist conventional chemotherapies (CTs) and radiotherapies (RTs), making surgical resection a crucial intervention. However, achieving radical resection for chordomas is seldom possible, presenting therapeutic challenges. The accurate diagnosis of these tumors is vital for their distinct prognoses, yet differentiation is hindered by overlapping radiological and histopathological features. Fortunately, recent molecular and genetic studies, including extracranial location analysis, offer valuable insights for precise diagnosis. This literature review delves into the genetic aberrations and molecular biology of chordomas, aiming to provide an overview of more successful therapeutic strategies. Methods: A systematic search was conducted across major medical databases (PubMed, Embase, and Cochrane Library) up to 28 January 2023. The search strategy utilized relevant Medical Subject Heading (MeSH) terms and keywords related to "chordomas", "molecular biology", "gene aberrations", and "target therapies". The studies included in this review consist of preclinical cell studies, case reports, case series, randomized controlled trials, non-randomized controlled trials, and cohort studies reporting on genetic and biological aberrations in chordomas. Results: Of the initial 297 articles identified, 40 articles were included in the article. Two tables highlighted clinical studies and ongoing clinical trials, encompassing 18 and 22 studies, respectively. The clinical studies involved 185 patients diagnosed with chordomas. The tumor sites were predominantly sacral (n = 8, 44.4%), followed by clivus (n = 7, 38.9%) and lumbar spine (n = 3, 16.7%). Primary treatments preceding targeted therapies included surgery (n = 10, 55.6%), RT (n = 9, 50.0%), and systemic treatments (n = 7, 38.9%). Various agents targeting specific molecular pathways were analyzed in the studies, such as imatinib (a tyrosine kinase inhibitor), erlotinib, and bevacizumab, which target EGFR/VEGFR. Common adverse events included fatigue (47.1%), skin reactions (32.4%), hypertension (23.5%), diarrhea (17.6%), and thyroid abnormalities (5.9%). Clinical outcomes were systematically assessed based on progression-free survival (PFS), overall survival (OS), and tumor response evaluated using RECIST or CHOI criteria. Notably, stable disease (SD) occurred in 58.1% of cases, and partial responses (PRs) were observed in 28.2% of patients, while 13.7% experienced disease progression (PD) despite targeted therapy. Among the 22 clinical trials included in the analysis, Phase II trials were the most prevalent (40.9%), followed by I-II trials (31.8%) and Phase I trials (27.3%). PD-1 inhibitors were the most frequently utilized, appearing in 50% of the trials, followed by PD-L1 inhibitors (36.4%), CTLA-4 inhibitors (22.7%), and mTOR inhibitors (13.6%). Conclusions: This systematic review provides an extensive overview of the state of targeted therapy for chordomas, highlighting their potential to stabilize the illness and enhance clinical outcomes.

A Review of Ultrasound-Mediated Checkpoint Inhibitor Immunotherapy

Over the past decade, immunotherapy has emerged as a major modality in cancer medicine. However, despite its unprecedented success, immunotherapy currently benefits only a subgroup of patients, may induce responses of limited duration and is associated with potentially treatment-limiting side effects. In addition, responses to immunotherapeutics are sometimes diminished by the emergence of a complex array of resistance mechanisms. The efficacy of immunotherapy depends on dynamic interactions between tumour cells and the immune landscape in the tumour microenvironment. Ultrasound, especially in conjunction with cavitation-promoting agents such as microbubbles, can assist in the uptake and/or local release of immunotherapeutic agents at specific target sites, thereby increasing treatment efficacy and reducing systemic toxicity. There is also increasing evidence that ultrasound and/or cavitation may themselves directly stimulate a beneficial immune response. In this review, we summarize the latest developments in the use of ultrasound and cavitation agents to promote checkpoint inhibitor immunotherapy.

Progress and prospects of targeted therapy and immunotherapy for urachal carcinoma

Introduction: Urachal carcinoma (UrC) is a rare and aggressive disease. Systematic chemotherapy shows limited efficacy in patients with advanced disease, while targeted therapy and immunotherapy may provide a reasonable alternative for specific populations. The molecular pattern of colorectal cancer (CRC) have recently been identified; this understanding has significantly influenced the clinical management of CRC in terms of molecular-targeted therapy. Although some genetic alterations have been associated with UrC, there is still no systematic overview of the molecular profile of this rare malignancy. Methods: In this review, we comprehensively discuss the molecular profile of UrC and further identify potential targets for the personalized treatment of UrC as well as immune checkpoint inhibitors that represent underlying biomarkers. A systematic literature search was carried out by searching the PubMed, EMBASE, and Web of Science databases to identify all literature related to targeted therapy and immunotherapy in urachal carcinoma from inception to February 2023. Results: A total of 28 articles were eligible, and most studies included were case report sand retrospective case series. Furthermore, 420 cases of UrC were identified to analyze the association between mutations and UrC. The most commonly mutated gene in UrC was TP53 with the prevalence of 70%, followed by KRAS mutations in 28.3%, MYC mutations in 20.3%, SMAD4 mutations in 18.2% and GNAS mutations in 18%, amongst other genes. Discussion: The molecular patterns of UrC and CRC are similar yet distinct. Notably, targeted therapy, especially EGFR-targeting therapy, might provide curative efficacy for patients with UrC by applying specific molecular markers. Additional potential biomarkers for the immunotherapy of UrC are mismatch repair (MMR) status and PD-L1 expression profile. In addition, combined regimens featuring targeted agents and immune checkpoint blockers might increase antitumor activity and exert better efficacy in UrC patients with specific mutational burden.

Receptor-ligand pair typing and prognostic risk model of response or resistance to immune checkpoint inhibitors in lung adenocarcinoma

Introduction

Currently, programmed cell death-1 (PD-1)-targeted treatment is ineffective for a sizable minority of patients, and drug resistance still cannot be overcome.

Methods

To explore the mechanisms of immunotherapy and identify new therapeutic opportunities in lung adenocarcinoma (LUAD), data from patients who did and did not respond to the anti-PD-1 treatment were evaluated using single-cell RNA sequencing, and bulk RNA sequencing were collected.

Results

We investigated the gene expression that respond or not respond to immunotherapy in diverse cell types and revealed transcriptional characteristics at the single-cell level. To ultimately explore the molecular response or resistance to anti-PD-1 therapy, cell-cell interactions were carried out to identify the different LRIs (ligand-receptor interactions) between untreated patients vs. no-responders, untreated patients vs. responders, and responders vs. non-responders. Next, two molecular subgroups were proposed based on 73 LRI genes, and subtype 1 had a poor survival status and was likely to be the immunosuppressive tumor subtype. Furthermore, based on the LASSO Cox regression analysis results, we found that TNFSF13, AXL, KLRK1, FAS, PROS1, and CDH1 can be distinct prognostic biomarkers, immune infiltration levels, and responses to immunotherapy in LUAD.

Discussion

Altogether, the effects of immunotherapy were connected to LRIs scores, indicating that potential medications targeting these LRIs could contribute to the clinical benefit of immunotherapy. Our integrative omics analysis revealed the mechanisms underlying the anti-PD-1 therapy response and offered abundant clues for potential strategies to improve precise diagnosis and immunotherapy.

Prognostic value and immunological role of FOXM1 in human solid tumors

FOXM1 acts as an oncogenic transcription factor and is involved in multiple hallmarks of human malignancies. Recent studies have demonstrated that FOXM1 is upregulated and correlated with poor prognosis in a majority of cancers. However, there are few pan-cancer analyses of FOXM1. This study aimed to investigate the expression profiles and clinical significance of FOXM1 in 31 types of solid tumors. We explored the expression profiles and the prognostic value of FOXM1 in pan-cancer across The Cancer Genome Atlas (TCGA). We further used lung adenocarcinoma (LUAD) tissues combined with quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC) for experimental validation of FOXM1 expression. Besides, we verified the function of FOXM1 in a lung cancer cell line. Gene set enrichment analysis (GSEA) was conducted to explore signaling pathways related to FOXM1 expression. We observed that up-regulated FOXM1 was significantly related to poor survival in most tumors. Furthermore, there are significant correlations between FOXM1 expression and the infiltrating levels of different types of immune cells, TMB, MSI and immune checkpoint genes in a variety of cancers. Additional analysis based on IMvigor 210 cohort confirmed that patients with high level of FOXM1 exhibited a superior response to anti-PD-L1 therapy, and had a prolonged OS. In conclusion, this study indicated that FOXM1 could serve as a prognostic biomarker for most types of cancers and played a crucial role in the tumor immune microenvironment.

Reprogramming the tumor microenvironment to improve the efficacy of cancer immunotherapies

The immunotherapeutic approaches based on checkpoint inhibitors, tumor vaccination, immune cell-based therapy, and cytokines were developed to engage the patient's immune system against cancer and better survival of them. While potent, however, preclinical and clinical data have identified that abnormalities in the tumor microenvironment (TME) can affect the efficacy of immunotherapies in some cancers. It is therefore imperative to develop new therapeutic interventions that will enable to overcome tumor-supportive TME and restrain anti-tumor immunity in patients that acquire resistance to current immunotherapies. Therefore, recognition of the essential nature of the tolerogenic TME may lead to a shift from the immune-suppressive TME to an immune-stimulating phenotype. Here, we review the composition of the TME and its effect on tumor immunoediting and then present how targeted monotherapy or combination therapies can be employed for reprogramming educated TME to improve current immunotherapies outcomes or elucidate potential therapeutic targets.

Identification and Verification of an Alternative Polyadenylation-Related lncRNA Prognostic Signature for Glioma

Due to the high mortality and modality of glioma, it was urgently needed to develop a glioma prognostic assessment system. Previous studies demonstrated that alternative polyadenylation- (APA-) related genes are important in immune response and oncogenesis. mRNA and lncRNA expression information of glioma samples were acquired from CGGA and TCGA databases, and lncRNAs associated with APA were selected through correlation analysis. The prognosis model of APA-related lncRNAs was built by the univariate Cox, random forest, and univariate Cox regression analyses. Glioma samples were assigned into high- and low-risk groups. Independence and effectiveness of the prognostic model were evaluated by Kaplan-Meier analysis, ROC curve, and Cox regression analyses. GO, KEGG enrichment, and GSEA analyses showed that the mainly involved signaling pathways were enriched in cellular immunity and immune signal transduction. We further analyzed expression differences of negative immune regulatory genes and immune cell infiltration degree between two groups. Immune checkpoints CTLA4 and LAG3 and immune suppressors TGFB, IL10, NOS3, and IDO1 and immune cell infiltration were notably upregulated in the high-risk group. The PD1/PDL1 expression was significantly correlated with risk score, showing that the prognostic model of APA-related lncRNA could effectively assess the tumor immune suppression. In conclusion, we established a risk assessment model of APA-related lncRNA in glioma, which could effectively evaluate prognosis of patients with glioma and tumor immune suppression and could provide guidance for clinical treatment.

Multi-target combinatory strategy to overcome tumor immune escape

Immune therapy has become the fourth approach after surgery, chemotherapy, and radiotherapy in cancer treatment. Many immune checkpoints were identified in the last decade since ipilimumab, which is the first immune checkpoint inhibitor to cytotoxic T-lymphocyte associated protein 4, had been approved by the US Food and Drug Administration (FDA) for the treatment of unresectable or metastatic melanoma in 2011. The use of several antibody drugs that target PD1/PD-L1 for various cancer treatments has been approved by the FDA. However, fewer people are benefitting from immune checkpoint inhibitor treatment in solid cancers. Approximately 80% of patients do not respond appropriately because of primary or acquired therapeutic resistance. Along with the characterization of more immune checkpoints, the combinatory treatment of multiimmune checkpoint inhibitors becomes a new option when monotherapy could not receive a good response. In this work, the author focuses on the combination therapy of multiple immune checkpoints (does not include targeted therapy of oncogenes or chemotherapy), introduces the current progression of multiple immune checkpoints and their related inhibitors, and discusses the advantages of combination therapy, as well as the risk of immune-related adverse events.

Cell membrane coated-nanoparticles for cancer immunotherapy

Cancer immunotherapy can effectively inhibit cancer progression by activating the autoimmune system, with low toxicity and high effectiveness. Some of cancer immunotherapy had positive effects on clinical cancer treatment. However, cancer immunotherapy is still restricted by cancer heterogeneity, immune cell disability, tumor immunosuppressive microenvironment and systemic immune toxicity. Cell membrane-coated nanoparticles (CMCNs) inherit abundant source cell-relevant functions, including “self” markers, cross-talking with the immune system, biological targeting, and homing to specific regions. These enable them to possess preferred characteristics, including better biological compatibility, weak immunogenicity, immune escaping, a prolonged circulation, and tumor targeting. Therefore, they are applied to precisely deliver drugs and promote the effect of cancer immunotherapy. In the review, we summarize the latest researches of biomimetic CMCNs for cancer immunotherapy, outline the existing specific cancer immune therapies, explore the unique functions and molecular mechanisms of various cell membrane-coated nanoparticles, and analyze the challenges which CMCNs face in clinical translation.

Overexpression of transposable elements is associated with immune evasion and poor outcome in colorectal cancer

AIM

High immune cell infiltration of the tumour microenvironment is generally associated with a good prognosis in solid cancers. However, a subset of patients with colorectal cancer (CRC) tumours with high immune cell infiltration have a poor outcome. These tumours have a high level of T cell infiltration and are also characterised by increased expression of programmed death-ligand 1 (PD-L1). As these tumours comprise both microsatellite instability and microsatellite stable subtypes, the mechanism underlying this phenotype is unknown.

METHODS

Using RNA-seq data from The Cancer Genome Atlas, we quantified transposable element (TE) expression and developed a TE expression score that is predictive of prognosis and immune infiltration independent of microsatellite instability status and tumour staging in CRC.

RESULTS

Tumours with the highest TE expression score showed increased immune cell infiltration with upregulation of interferon (IFN) signalling pathways and downstream activation of IFN-simulated genes. As expected, cell lines treated with DNA methyltransferase inhibitor mimicked patient tumours with increased TE expression and IFN signalling. However, surprisingly, unlike high TE expressing CRC, there is little evidence for the activation of JAK-STAT signalling and PD-L1 expression in DNA methyltransferase inhibitor-treated cells. Single-cell RNA-seq analysis of CRC samples showed that PD-L1 expression is mainly confined to tumour-associated macrophages and T cells, suggesting that TE mediated IFN signalling is triggering expression of PD-L1 in immune cells rather than in tumour cells.

CONCLUSIONS

Our study uncovers a novel mechanism of TE driven immune evasion and highlights TE expression as an important factor for patient prognosis in CRC.

Her2-Positive and Microsatellite Instability Status in Gastric Cancer-Clinicopathological Implications

Gastric cancer (GC) is one of the leading causes of cancer-related death. The combination of new molecular classifications with clinicopathological data could contribute to the individualization of patients and to the development of new therapeutic strategies. We examined the various associations in two molecular types of GC: HER2-positive (human epidermal growth factor receptor 2) and microsatellite instability (MSI), assessing their influence on treatment and prognosis. A retrospective study of 142 GC patients was performed with molecular characterization through HER2 overexpression and DNA repair protein expression for MSI. The percentage of HER2-positive tumors was 13.4%, predominantly in men. Correlations were found with intestinal type, metastases, advanced stages and chemotherapy. Almost 75% of HER2-positive patients died. MSI occurred in 16.2%, associated with advanced age, female sex, distal location and intestinal type. These patients had few metastases and low stages. The percentage of deaths was higher among MSI patients who received perioperative chemotherapy. The determination of HER2 and MSI status in GC is important for their association with specific clinicopathological features and for their prognostic and predictive value.

Understanding the tumor microenvironment for effective immunotherapy

Advances in immunotherapy have led to durable and long-term benefits in a subset of patients across a number of solid tumor types. Understanding of the subsets of patients that respond to immune checkpoint inhibitors at the cellular level, and in the context of their tumor microenvironment (TME) is becoming increasingly important. The TME is composed of a heterogeneous milieu of tumor and immune cells. The immune landscape of the TME can inhibit or promote tumor initiation and progression; thus, a deeper understanding of tumor immunity is necessary to develop immunotherapeutic strategies. Recent developments have focused on characterizing the TME immune contexture (type, density, and function) to discover mechanisms and biomarkers that may predict treatment outcomes. This has, in part, been powered by advancements in spatial characterization technologies. In this review article, we address the role of specific immune cells within the TME at various stages of tumor progression and how the immune contexture determinants affecting tumor growth are used therapeutically.

Expression profiles of gastric cancer molecular subtypes in remnant tumors

BACKGROUND

Remnant gastric cancer (RGC) is a carcinoma arising in the stomach remnant after previous gastric resection. It is frequently reported as a tumor with a poor prognosis and distinct biological features from primary gastric cancer (PGC). However, as it is less frequent, its profile regarding the current molecular classifications of gastric cancer has not been evaluated.

AIM

To evaluate a cohort of RGC according to molecular subtypes of GC using a panel of immunohistochemistry and in situ hybridization to determine whether the expression profile is different between PGC and RGC.

METHODS

Consecutive RGC patients who underwent gastrectomy between 2009 and 2019 were assessed using seven GC panels: Epstein-Barr virus in situ hybridization, immunohistochemistry for mismatch repair proteins (MutL homolog 1, MutS homolog 2, MutS homolog 6, and PMS1 homolog 2), p53 protein, and E-cadherin expression. Clinicopathological characteristics and survival of these patients were compared to 284 PGC patients.

RESULTS

A total of 40 RGC patients were enrolled in this study. Compared to PGC, older age (P < 0.001), male (P < 0.001), lower body mass index (P = 0.010), and lower hemoglobin level (P < 0.001) were associated with RGC patients. No difference was observed regarding Lauren’s type and pathologic Tumor Node Metastasis stage between the groups. Regarding the profiles evaluated, EBV-positive tumors were higher in RGC compared to PGC (P = 0.039). The frequency of microsatellite instability, aberrant p53 immunostaining, and loss of E-cadherin expression were similar between RGC and PGC. Higher rates of simultaneous alterations in two or more profiles were observed in RGC compared to PGC (P < 0.001). According to the molecular classification, the subtypes were defined as EBV in nine (22.5%) cases, microsatellite instability in nine (22.5%) cases, genomically stable in one (2.5%) case, and chromosomal instability in 21 (52.5%) cases. There was no significant difference in survival between molecular subtypes in RGC patients.

CONCLUSION

RGC was associated with EBV positivity and higher rates of co-altered expression profiles compared to PGC. According to the molecular classification, there was no significant difference in survival between the subtypes of RGC.

Analysis of the PD-1 Ligands Among Gastrointestinal Cancer Patients: Focus on Cancer Immunity

Many types of gastrointestinal cancer have shown promising outcomes after checkpoint blockade immunotherapy; however, it remains largely unclear about the expression profiles of programmed death 1 (PD-1) ligands (CD274 and PDCD1LG2) in the context of human pan-cancer. This work comprehensively analyzed the expression pattern of the PD-1 ligands and the clinical significance in the prognosis prediction among the seven types of gastrointestinal malignancies collected from The Cancer Genome Atlas (TCGA) and the Cancer Cell Line Encyclopedia (CCLE) database. Furthermore, the correlation of CD274/PDCD1LG2 with cancer immunity was also explored. The patients with liver hepatocellular carcinoma (LIHC) receiving cytokine-induced killer (CIK) cell immunotherapy at our cancer center were enrolled. CD274 and PDCD1LG2 displayed inconsistent gene expression levels among the diverse cancer cell lines. Typically, the abnormal expression level of CD274 and PDCD1LG2 was detected in both esophageal carcinoma (ESCA) and stomach adenocarcinoma (STAD), where PDCD1LG2 was related to the overall survival (OS) of the patients in ESCA (p = 0.015) and STAD (p = 0.025). High-serum CD274 and PDCD1LG2 levels predicted a worse survival in the patients with LIHC receiving CIK therapy. More importantly, the expression level of CD274 and PDCD1LG2 was significantly correlated with the degree of Estimation of STromal and Immune cells in MAlignant Tumor tissues using the Expression data (ESTIMATE). In addition, we found that CD274 and PDCD1LG2 were correlated with gene markers in tumor-infiltrating immune cells. Furthermore, the expression of CD274 and PDCD1LG2 was correlated with tumor mutation burden (TMB), microsatellite instability (MSI), mismatch repair (MMR), and DNA methyltransferase (DNMT) of different types of cancers. The present work comprehensively analyzed a RNA sequencing of the PD-1 ligands across the seven distinct types of gastrointestinal cancers, which provided clues for further studies in cancer immunity and development.

Expression of PD1/PDL1 in gastric cancer at different microsatellite status and its correlation with infiltrating immune cells in the tumor microenvironment

Objective: The microsatellite status and tumor immune microenvironment have a remarkable influence on tumor immunotherapy. This study was performed to investigate programmed cell death protein 1/programmed death ligand 1 (PD1/PDL1) expression and their correlations with CD8+ T cell/CD68+ macrophage (CD68+ M) densities in gastric cancer (GC) at different microsatellite statuses.

Methods: The expression of MLH1, PMS2, MSH2, and MSH6 was detected via immunohistochemistry (IHC) to determine the microsatellite status in 215 GC samples obtained from surgical resections. Furthermore, the expression of PD1, PDL1, CD8, and CD68 was detected in the samples via IHC, and the differences and correlations in GC at different microsatellite statuses were then analyzed. PDL1 expression in tumor cells was labeled as PDL1[T], while expression of PD1 and PDL1 in tumor-infiltrating immune cells was labeled as PD1 and PDL1, respectively. Kaplan-Meier analysis was used to evaluate the significance of PD1/PDL1 expression in determining overall survival. Multivariate Cox regression analysis was performed using SPSS software. P-values were determined using the log-rank test.

Results: Our results indicated that PD1, PDL1[T], and PDL1 positivity rates were 59%, 35%, and 57% in 46 microsatellite unstable (MSI) GCs and 45%, 22%, and 40% in 169 microsatellite stable (MSS) GCs, respectively. Compared with MSS GC, PD1, PDL1[T], and PDL1 expression was higher in MSI GC (P = 0.109, 0.090, and 0.044, respectively). Additionally, CD8+ T cell and CD68+ M densities were higher in MSI GC than in MSS GC (P = 0.537 and <0.001, respectively). Additionally, CD8+ T cell/CD68+ M densities were evaluated according to tumor center and invasion front. We found that PD1 expression was significantly correlated with CD8+ T cell density at the invasion front of the MSI GC (P = 0.031), whereas PDL1 expression was significantly correlated to high CD68+ M density in the tumor center and invasion front of MSS GC (P = 0.001 and 0.014, respectively). Survival analysis showed that patients with PD1-positive and PDL1[T]/PDL1-negative GC had better prognosis (P = 0.012, 0.005, and 0.022, respectively). Multivariate Cox survival analysis showed that PDL1[T] was an independent prognostic factor for GC.

Conclusion: The results suggested that PD1/PDL1 expression and immune response varied at different microsatellite statuses in GC. PD1/PDL1 expression was correlated with CD8+ T cell/CD68+ M densities in GC at different microsatellite statuses, especially at the invasion front. The patients exhibiting high PD1/PDL1 expression or high CD8+ T cell/CD68+ M densities MSI GC might be potential beneficiaries of PD1/PDL1 immunotherapy.

An integrated pan-cancer analysis of TFAP4 aberrations and the potential clinical implications for cancer immunity

Studies have shown that transcription factor activating enhancer binding protein 4 (TFAP4) plays a vital role in multiple types of cancer; however, the TFAP4 expression profile is still unknown, as is its value within the human pan‐cancer analysis. The present study comprehensively analysed TFAP4 expression patterns from 33 types of malignancies, along with the significance of TFAP4 for prognosis prediction and cancer immunity. TFAP4 displayed inconsistent levels of gene expression across the diverse cancer cell lines, and displayed abnormal expression within most malignant tumours, which closely corresponded to overall survival. More importantly, the TFAP4 level was also significantly related to the degree of tumour infiltration. TFAP4 was correlated using gene markers in tumour‐infiltrating immune cells and immune scores. TFAP4 expression was correlated with tumour mutation burden and microsatellite instability in different cancer types, and enrichment analyses identified TFAP4‐associated terms and pathways. The present study comprehensively analysed the expression of TFAP4 across 33 distinct types of cancers, which revealed that TFAP4 may possibly play a vital role during cancer formation and development. TFAP4 is related to differing degrees of immune infiltration within cancers, which suggests the potential of TFAP4 as an immunotherapy target in cancers. Our study demonstrated that TFAP4 plays an important role in tumorigenesis as a prognostic biomarker, which highlights the possibility of developing new targeted treatments.

Clinical Implications of Aberrant PD-1 and CTLA4 Expression for Cancer Immunity and Prognosis: A Pan-Cancer Study

Combination therapy with inhibitors of cytotoxic T lymphocyte-associated protein (CTLA)4 and programmed death (PD)-1 has demonstrated efficacy in cancer patients. However, there is little information on CTLA4 and PD-1 expression levels and their clinical significance across diverse cancers. In this study, we addressed this question by analyzing PD-1 and CTLA4 levels in 33 different types of cancer along with their prognostic significance using The Cancer Genome Atlas (TCGA) and Cancer Cell Line Encyclopedia datasets. Liver hepatocellular carcinoma (LIHC) patients receiving cytokine-induced killer cell (CIK) immunotherapy at Sun Yat-sen University cancer center were enrolled for survival analysis. The correlation between PD-1/CTLA4 expression and cancer immunity was also analyzed. The results showed that PD-1 and CTLA4 transcript levels varied across cancer cell lines, with aberrant expression detected in certain cancer types; Kaplan–Meier analysis with the Cox proportional hazards model showed that this was closely related to overall survival in breast invasive carcinoma, glioblastoma multiforme, head and neck squamous cell carcinoma, acute myeloid leukemialymphoma, uterine corpus endometrial carcinoma, and uveal melanoma in TCGA. High serum PD-1 and CTLA4 levels predicted better survival in LIHC patients receiving CIK therapy. PD-1 and CTLA4 levels were found to be significantly correlated with the degree of tumor cell infiltration using Tumor Immune Estimation Resource, Estimating Relative Subsets of RNA Transcripts, and Estimation of Stromal and immune Cells in Malignant Tumor Tissues Using Expression Data as well as with tumor-infiltrating lymphocyte marker expression; they were also related to tumor mutation burden, microsatellite instability, mismatch repair, and the expression of DNA methyltransferases in some cancer types. Gene set enrichment analysis of 33 cancer types provided further evidence for associations between PD-1/CTLA4 levels and cancer development and immunocyte infiltration. Thus, PD-1 and CTLA4 play important roles in tumorigenesis and tumor immunity and can serve as prognostic biomarkers in different cancer types.

Prognostic Value of Vimentin Is Associated With Immunosuppression in Metastatic Renal Cell Carcinoma

Introduction: Vimentin, a classical marker of epithelial–mesenchymal transition, reflects the invasiveness of cancer cells. Its role in the genesis and progression of tumor has been reported in various cancers, including renal cell carcinoma. However, the impact of vimentin on tumor microenvironment, particularly its implication with tumor-infiltrating immune cells, is unknown.

Methods: We conducted this study in 231 patients with metastatic renal cell carcinoma (mRCC) to determine the potential relationship between vimentin and immune status. Using immunohistochemical staining, expression of vimentin, CD8, FOXP3, programmed cell death protein 1 (PD-1), and programmed cell death ligand 1 (PD-L1) were evaluated in resected tumor tissue. Kaplan–Meier analysis and Cox regression models were used for survival analysis. Chi-square test, Fisher exact test, and Mann–Whitney U-test were used for comparison between vimentin high and low groups.

Results: High expression of vimentin, stroma PD-L1, and PD-1 indicated poor overall survival, whereas low regulatory T cell or high CD8+ T cell infiltration indicated long overall survival. Stroma PD-L1 (P = 0.030), vimentin (P = 0.026) expression, and CD8⁺ T cell infiltration (P < 0.001) were independent prognostic factors in mRCC. High vimentin expression was accompanied by high PD-1, PD-L1 expression, and increased regulatory T cell infiltration (all P < 0.001), indicating immunosuppression in the tumor microenvironment.

Conclusions: We revealed that vimentin expression was associated with immunosuppression in mRCC, and the immune-suppressive status might be possibly posed by PD-1/PD-L1. Patients with high vimentin expression may acquire potential benefit from the recently approved PD-1/PD-L1 inhibitors. However, further clinical trials are needed to validate our findings.

Are Immunohistochemical Markers Useful in Phenotypic Gastric Cancer Classification?

To identify useful markers for prognostic and therapeutic purposes, The Cancer Genome Atlas (TCGA) provided a molecular classification of gastric cancers (GCs). Previous studies have used immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) to define immunophenotypic surrogate markers of the molecular alterations. Some critical issues concerning the correct definition of immunophenotypic groups have emerged in these studies that employed tissue microarrays (TMAs). We performed an immunophenotypic classification by evaluating MLH1, p53, HER2, E-cadherin, and Epstein-Barr virus (EBV) on the whole section of the surgical GC samples compared to most of the studies conducted on TMAs. We also investigated the immunohistochemical expression of PD-L1, a known therapeutic target. We identified the following immunophenotypic groups: EBV (2.9%); mismatch repair deficient (MMR-D) (7.2%); overexpressed p53 and/or HER2+ (61.4%); aberrant E-cadherin (11.4%); and normal pattern (17.1%). The use of surgical samples emphasized that some immunohistochemical markers were not useful for properly classifying the GC specimens. We can state that EBV (significantly correlated to PD-L1 expression) and MMR-D GCs are well-defined groups, mutually exclusive, and easily assessable with IHC and CISH, and could be candidates for immunotherapy with PD-1/PD-L1 inhibitors. As regards p53, our findings suggest that IHC assessment may be responsible for a misclassification of GC groups. Immunohistochemical evaluation of E-cadherin needs to be standardized, particularly in terms of the heterogeneous cytoplasmic/membranous staining pattern. Whether to consider the normal-pattern group as a separate category remains to be clarified. Because GC specimens with known therapeutic targets account for only 40%, we suggest reviewing the immunophenotypic classification to find new therapeutic targets, such as PD-L1, MLH1, and HER2.

Pitfalls in Cancer Biomarker Discovery and Validation with Emphasis on Circulating Tumor DNA

Despite significant investment of funds and resources, few new cancer biomarkers have been introduced to the clinic in the last few decades. Although many candidates produce promising results in the laboratory, deficiencies in sensitivity, specificity, and predictive value make them less than desirable in a patient setting. This review will analyze these challenges in detail as well as discuss false discovery, problems with reproducibility, and tumor heterogeneity. Circulating tumor DNA (ctDNA), an emerging cancer biomarker, is also analyzed, particularly in the contexts of assay specificity, sensitivity, fragmentation, lead time, mutant allele fraction, and clinical relevance. Emerging artificial intelligence technologies will likely be valuable tools in maximizing the clinical utility of ctDNA which is often found in very small quantities in patients with early-stage tumors. Finally, the implications of challenging false discoveries are examined and some insights about improving cancer biomarker discovery are provided.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

Cancer immunotherapy: Pros, cons and beyond

Cancer immunotherapy is an innovative treatment for tumors today. In various experiments and clinical studies, it has been found that immunotherapy does have incomparable advantages over traditional anti-tumor therapy, which can prolong progression-free survival (PFS) and overall survival (OS). However, immunotherapy has obvious complexity and uncertainty. Immunotherapy may also cause severe adverse reactions due to an overactive immune system. More effective and fewer adverse reactions immunological checkpoints are still under further exploration. This review gives an overview of recent developments in immunotherapy and indicates a new direction of tumor treatment through analyzing the pros and cons of immunotherapy coupled with keeping a close watch on the development trend of the immunotherapy future.

Microsatellite instability: a review of what the oncologist should know

The patients with high microsatellite instability (MSI-H)/mismatch repair deficient (dMMR) tumors recently have been reported that can benefit from immunotherapy, and MSI can be used as a genetic instability of a tumor detection index. However, many studies have shown that there are many heterogeneous phenomena in patients with MSI tumors in terms of immunotherapy, prognosis and chemotherapy sensitivity. Here we mainly review the research results of MSI detection methods, the mechanisms of MSI occurrence and its relationship with related tumors, aiming to make a brief analysis of the current research status of MSI and provide comparable reference and guidance value for further research in this field.

Tumour mismatch repair protein loss is associated with advanced stage in oral cavity squamous cell carcinoma

An unexplained increase in the incidence of oral cavity squamous cell carcinoma (oSCC) has been observed despite decreasing smoking rates, particularly in younger patients. Links to defects in the DNA mismatch repair (MMR) system are well established in early onset colorectal, urothelial and gynaecological malignancies. MMR deficient patients treated with immune checkpoint inhibitors have demonstrated improved response rates. Studies exploring MMR status in head and neck squamous cell carcinoma (HNSCC) demonstrate conflicting results. This study explores the incidence of MMR protein loss and its association with clinicopathological features and outcome in oSCC. Immunohistochemical staining using tissue microarrays to assess the expression of MMR proteins (hMLH1, hMSH2, hMSH6, and hPMS2) was performed on 285 consecutive oSCC cases between 2000 and 2016. Data on smoking, alcohol and metachronous malignancies were retrospectively collected. Proportional hazards regression models were used to compare survival in MMR intact and deficient patients. MMR deficiency was seen in 21 patients (7.4%). MMR deficient tumours were associated with bone invasion (52% vs 32%, p=0.05), higher pT stage (pT4 in 57% vs 35%, p<0.001) and a higher number of metachronous malignancies (p=0.05). MMR deficiency was not associated with younger age at presentation or absence of smoking or alcohol. There was no significant association between MMR status and survival (overall survival hazard ratio 1.36; p=0.32). The incidence of MMR loss in oSCC is low and is not associated with young age at presentation. MMR deficiency in oSCC is associated with an increase in the number of metachronous malignancies and more advanced primary tumours.

Liver graft rejection following immune checkpoint inhibitors treatment: a review

Immune checkpoint inhibitors (ICIs) have demonstrated remarkable efficacy in a variety of solid tumors; nonetheless, they have not been well investigated and are still recognized as a relative contraindication for patients with a liver transplantation (LT) history, since ICIs treatment might potentially lead to graft rejection. The program death-1 (PD-1) and the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) pathways are implicated in the tolerance of transplanted organ, as well as blockade of the pathways, which contribute to eliminating tumors and may inadvertently lead to peripheral transplant rejection. Currently, no guidelines are available regarding the treatment for ICIs patients with a prior LT history. Therefore, this study was carried out to review the recent studies, attempting to introduce the ICIs-related graft rejection after LT from various aspects. We believed that ICIs could be given for the well-informed patients receiving LT and developed recurrence in a controlled setting. Typically, these patients should be treated according to a clinical care path or a prospective clinical trial, so as obtain a persistent anti-tumor immune response in the meantime of avoiding graft rejection, adjust the immunosuppression, reduce the possibility of graft loss following rejection, and have the opportunity to develop biomarkers for tumor response and transplant rejection.

Relationship between T-cell receptor α gene polymorphisms and symptomatic differences in patients with narcolepsy type 1

Supplemental Digital Content is available in the text

Background:

Recent genome-wide association studies have identified an important role of T-cell receptor α (TRA) gene in the development of narcolepsy type 1. However, the role of TRA haplotype polymorphisms in the symptomatic diversity of narcolepsy remains unclear. This study aimed to investigate whether TRA polymorphisms can influence the symptomatic diversity of narcolepsy.

Methods:

Totally, 903 patients with narcolepsy type 1 were included in the study. Patients were divided into different groups according to their symptoms. First, 13 genotyped single nucleotide polymorphisms in the TRA were assessed for their association with symptoms of narcolepsy. We used the Chi-square test to determine differences in genotype frequencies in patients with narcolepsy. Further, we identified the haplotypes and variations of the TRA and tested their association with the symptoms of narcolepsy using a logistic regression model.

Results:

According to the results of the logistic regression, TRA haplotypes TG and CT were significantly associated with auditory hallucination, with odds ratios of 1.235 (95% confidence interval [CI], 1.012–1.507) and 1.236 (95% CI, 1.012–1.511), respectively (P < 0.05).

Conclusions:

The patterns of haplotype in TRA (haplotypes TG and CT) are associated with hypnagogic auditory hallucination in patients with narcolepsy type 1. However, further studies are needed to confirm our results and explore the underlying mechanisms.

PD-L1 is a double-edged sword in colorectal cancer: the prognostic value of PD-L1 depends on the cell type expressing PD-L1

PURPOSE

To investigate the associations between programmed cell death ligand-1 (PD-L1) on tumor cells (TCs) or PD-L1 on tumor-infiltrating immune cells (TIICs) and the microsatellite instability (MSI) status in colorectal cancer (CRC).

METHODS

In total, 238 CRC patients were enrolled. PD-L1 expression and MSI status were studied by immunohistochemical staining and polymerase chain reaction. The χ² test was used to compare characteristics. The Kaplan-Meier method was used for survival analysis. Cox proportional hazards models were used to determine the prognostic influence of clinicopathological factors.

RESULTS

Eighteen patients (7.6%) were had MSI-high (MSI-H) CRC. The number of patients with PD-L1 expression on TCs, stromal TIICs and intraepithelial TIICs was 13 (5.5%), 64 (26.9%) and 45 (18.9%), respectively. The MSI-H phenotype was significantly associated with younger age, right sidedness, mucinous component, high grade, stromal TIICs expressing PD-L1 (P = 0.042) and intraepithelial TIICs expressing PD-L1 (P < 0.001), but not TCs expressing PD-L1. PD-L1-expressing TCs were an independent marker of poor prognosis [hazard ratio (HR) = 3.387, P = 0.003], and PD-L1-expressing stromal TIICs were an independent marker of good prognosis (HR = 0.551, P < 0.001).

CONCLUSIONS

PD-L1-expressing TCs were a marker of poor prognosis; in contrast, PD-L1-expressing TIICs were a marker of good prognosis. The MSI-H phenotype was associated with the presence of PD-L1-expressing TIICs, but not of PD-L1-expressing TCs.

Minimal microsatellite shift in microsatellite instability high endometrial cancer: a significant pitfall in diagnostic interpretation

Mismatch-repair deficiency testing plays a critical role in the identification of proband in Lynch Syndrome families and triaging patients with high stage or recurrent solid malignancies for check point inhibitor (Pembrolizumab) immunotherapy. We compared microsatellite shift patterns of microsatellite instability PCR analysis at 5 NCI recommended loci between microsatellite instability high endometrial carcinoma (n = 50) and microsatellite instability high colorectal cancer (n = 19). The endometrial cancer cohort included 45 endometrioid, 1 serous, and 4 clear cell carcinomas. Overall, 52% (26/50) of microsatellite instability high endometrial cancers showed minimal microsatellite shift (defined as a one to three nucleotide repeat shift at an involved locus) observed at least at one locus. Among microsatellite instability high endometrial cancers with minimal microsatellite shift, the frequencies at each involved locus were D2S123 (21/21, 100%), D17S250 (10/11, 89%), D5S346 (11/12, 92%), BAT25 (9/12, 80%), and BAT26 (8/21, 45%). Noticeably, 11 of the 26 cases (42%) showed only minimal shift. Among microsatellite instability high endometrial cancers with minimal microsatellite shift, 65% (17/26) had combined MLH1 and PMS2 loss, 8% (2/26) had combined MSH2 and MSH6 loss, 13% (3/26) had MSH6 loss and 15% (4/26) had loss of PMS2 by immunohistochemistry. In contrast, only 16% (3/19) had minimal microsatellite shift seen in colorectal cancer cohort with corresponding loss of MLH1/PMS2, MSH2/MSH6, or MSH6. Overall, 15% (7/50) of microsatellite instability high endometrial carcinomas showed isolated loss of MSH6 in contrast to 7% (1/15) seen in microsatellite instability high colorectal carcinomas. In conclusion, microsatellite instability high endometrial carcinomas have a significantly higher frequency of minimal microsatellite shift that coincides with a high percentage of combined loss of MLH1/PMS2. Microsatellite instability high endometrial cancers also have more frequent loss of MSH-6. Diagnostically, recognition of minimal microsatellite shift is crucial for accurate interpretation of microsatellite instability PCR data of endometrial carcinoma.

The COX2 Effector Microsomal PGE2 Synthase 1 is a Regulator of Immunosuppression in Cutaneous Melanoma

PURPOSE

Microsomal prostaglandin E2 synthase 1 (mPGES1) was evaluated as an important downstream effector of the COX2 pathway responsible for tumor-mediated immunosuppression in melanoma.

EXPERIMENTAL DESIGN

The analysis of a stage III melanoma tissue microarray (n = 91) was performed to assess the association between mPGES1, COX2, CD8, and patient survival. Pharmacologic inhibitors and syngeneic mouse models using PTGES-knockout (KO) mouse melanoma cell lines were used to evaluate the mPGES1-mediated immunosuppressive function.

RESULTS

We observed correlations in expression and colocalization of COX2 and mPGES1, which are associated with increased expression of immunosuppressive markers in human melanoma. In a syngeneic melanoma mouse model, PTGES KO increased melanoma expression of PD-L1, increased infiltration of CD8a+ T cells, and CD8a+ dendritic cells into tumors and suppressed tumor growth. Durable tumor regression was observed in mice bearing PTGES KO tumors that were given anti-PD-1 therapy. Analysis of a stage III melanoma tissue microarray revealed significant associations between high mPGES1 expression and low CD8+ infiltration, which correlated with a shorter patient survival.

CONCLUSIONS

Our results are the first to illustrate a potential role for mPGES1 inhibition in melanoma immune evasion and selective targeting in supporting the durability of response to PD-1 checkpoint immunotherapy. More research effort in this drug development space is needed to validate the use of mPGES1 inhibitors as safe treatment options.

Screening responsive or resistant biomarkers of immune checkpoint inhibitors based on online databases

Immune checkpoint inhibitors are a promising strategy in the treatment of cancer, especially advanced types. However, not all patients are responsive to immune checkpoint inhibitors. The response rate depends on the immune microenvironment, tumor mutational burden (TMB), expression level of immune checkpoint proteins, and molecular subtypes of cancers. Along with the Cancer Genome Project, various open access databases, including The Cancer Genome Atlas and Gene Expression Omnibus, provide large volumes of data, which allow researchers to explore responsive or resistant biomarkers of immune checkpoint inhibitors. In this review, we introduced some methodologies on database selection, biomarker screening, current progress of immune checkpoint blockade in solid tumor treatment, possible mechanisms of drug resistance, strategies of overcoming resistance, and indications for immune checkpoint inhibitor therapy.

CD44v6 engages in colorectal cancer progression

CD44 is a transmembrane glycoprotein. When the CD44 gene is expressed, its pre-messenger RNA (mRNA) can be alternatively spliced into mature mRNAs that encode several CD44 isoforms. The mRNA assembles with ten standard exons, and the sixth variant exon encodes CD44v6, which engages in a variety of biological processes, including cell growth, apoptosis, migration, and angiogenesis. Mechanistically, CD44v6 interacts with hyaluronic acid (HA) or osteopontin, or it acts as a coreceptor for various cytokines, such as epidermal growth factor, vascular endothelial growth factor, hepatocyte growth factor, and C-X-C motif chemokine 12. In this context, the receptor tyrosine kinase or G protein-coupled receptor-associated signaling pathways, including mitogen-activated protein kinase/extracellular-signal-regulated kinase and phosphoinositide-3-kinase/Akt, are activated. Using these actions, homeostasis or regeneration can be facilitated among normal tissues. However, overexpression of the mature mRNA encoding CD44v6 can induce cancer progression. For example, CD44v6 assists colorectal cancer stem cells in colonization, invasion, and metastasis. Overexpression of CD44v6 predicts poor prognosis in patients with colorectal cancer, as patients with a large number of CD44v6-positive cells in their tumors are generally diagnosed at late stages. Thus, the clinical significance of CD44v6 in colorectal cancer deserves consideration. Preclinical results have indicated satisfactory efficacies of anti-CD44 therapy among several cancers, including prostate cancer, pancreatic cancer, and gastric cancer. Moreover, clinical trials aiming to evaluate the pharmacokinetics, pharmacodynamics, efficacy, and toxicity of a commercialized anti-CD44 monoclonal antibody developed by Roche (RO5429083) have been conducted among patients with CD44-expressing malignant tumors, and a clinical trial focusing on the dose escalation of this antibody is ongoing. Thus, we are hopeful that anti-CD44 therapy will be applied in the treatment of colorectal cancer in the future.

Immunohistochemical detection of PD-L1 among diverse human neoplasms in a reference laboratory: observations based upon 62,896 cases

Targeting of the PD1/PD-L1 immune checkpoint pathway has rapidly gained acceptance as a therapeutic strategy for a growing number of malignancies. Testing for expression of PD-L1 in tumor cells and immune cells has been used as a companion or complementary test for drugs targeting the PD1/PD-L1 pathway. We evaluated the results of PD-L1 testing in a large reference lab cohort. Using Food and Drug Administration-approved methods and interpretive instructions for each individual test, 62,896 cases were evaluated for PD-L1 using antibody clone 22C3, 28-8, SP142, or SP263. Case data analyzed included test results and information on tumor location and clinical history. No clinical outcome information was available and no attempt was made to correlate PD-L1 results with any other tests performed. The following numbers of cases were evaluated: 22C3 with tumor proportion score [n = 52585], 22C3 with combined positive score [n = 2631], 28-8 [n = 4191], SP142 [n = 850], and SP263 [n = 70]. In 22C3/tumor proportion score cases, the general results were as follows: negative 33.1% (n = 17,405), (low) expression 33.9% (n = 17,822), and high expression 29.5% (n = 15,486). In cases identified as metastatic, the results were as follows: negative 35.9% (n = 1411), (low) expression 30.8% (n = 1211), and high expression 30.7% (n = 1208). We found broad ranges of expression in tumor types with increasing positivity, as adenocarcinomas were reported as poorly differentiated, whereas squamous cell carcinomas showed more positivity as tumors were described as well-differentiated. The results of many individual tumor types were evaluated and showed, in general, high levels of positive expression. Practical challenges and observations of PD-L1 stain results and interpretation are also discussed.

Identification of discrepancy between CTLA4 expression and CTLA4 activation in gastric cancer

Objective: Recently, immune checkpoints blockers showed higher anti-tumor activity for advanced gastric cancer (GC). The purpose of the study is to find out predictive biomarkers related to anti-cytotoxic lymphocyte antigen 4 (CTLA4) therapy. Materials and methods: Datasets of gene expression omnibus (GEO), the cancer genome atlas (TCGA), and gene set enrichment analysis (GESA) were extracted. Differential expression of CTLA4 between cancer tissues and normal mucosa, enrichment of WT (wild type) vs. CTLA4_KO (knockout) upregulated gene set and clinical significance were analyzed. The expression of CTLA4, CD3, and granzyme A (GZMA) were validated on 30 cases of Chinese GC. Microsatellite instability (MSI) marker MLH1 and Epstein-Barr virus (EBV) marker EBER were examined on 30 cases of Chinese GC by immunohistochemistry and in situ hybridization. Results: CTLA4 was upregulated in GC tissue relative to normal mucosa in datasets of GSE27342 (fold change = 1.586, p < .001) and GSE63089 (fold change = 1.365, p < .001). Increased CTLA4 expression was positively related to CTLA4 activation. EBV-associated GC (EBVaGC) and microsatellite instability GC (MSIGC) disclosed higher CTLA4 levels than other GCs. Genomic stability GC (GSGC) also showed higher enrichment score of CTLA4 activation. CTLA4 activation resulted in shorter overall survival in GC. The expression level of CTLA4 was well correlated to expression levels of GZMA (R = 0.701, p < .001) and CD3 (R = 0.750, p < .001). Conclusions: Based on bioinformatics analysis, GSGC should be worth noticed as a potential GC subtypes responsive to anti-CTLA4 treatment.

Diosgenin promotes antitumor immunity and PD-1 antibody efficacy against melanoma by regulating intestinal microbiota

Diosgenin, a natural steroidal saponin, can exert antitumor effect by regulating immune function and improving intestinal microbiota. The response to anti-PD-1 immunotherapy is associated with intestinal microbiota and effector T cells in tumor microenvironment. We hypothesize that the modulation of diosgenin on intestinal microbiota can facilitate antitumor immunity and the therapeutic efficacy of PD-1 antibody. In melanoma-bearing C57BL/6 mice, we observed that the anti-melanoma effect of diosgenin relied more on antitumor immunity than direct tumor inhibition activity evidenced by obvious CD4⁺/CD8⁺ T-cell infiltration and IFN-γ expression in tumor tissues, and it could improve the compositions of intestinal microbiota. Antibiotics impaired the therapeutic efficacy and immunity responses of diosgenin through disturbing intestinal microbiota, indicating the importance of intestinal microbiota in diosgenin’s in vivo antitumor activity. More importantly, the combined administration of PD-1 antibody with diosgenin aggravated the tumor necrosis and apoptosis by eliciting augmented T-cell responses. Taken together, diosgenin can be used as a microecological regulator to induce antitumor immunity and improve the efficacy of immune checkpoint antibody, making it more suitable for the treatment of malignant tumors.

UBE2C Is a Potential Biomarker of Intestinal-Type Gastric Cancer With Chromosomal Instability

This study explored potential biomarkers associated with Lauren classification of gastric cancer. We screened microarray datasets on gastric cancer with information of Lauren classification in gene expression omnibus (GEO) database, and compared differentially expressing genes between intestinal-type or diffuse-type gastric cancer. Four sets of microarray data (GSE2669, GSE2680, GDS3438, and GDS4007) were enrolled into analysis. By differential gene analysis, UBE2C, CDH1, CENPF, ERO1L, SCD, SOX9, CKS1B, SPP1, MMP11, and ANLN were identified as the top genes related to intestinal-type gastric cancer, and MGP, FXYD1, FAT4, SIPA1L2, MUC5AC, MMP15, RAB23, FBLN1, ANXA10, and ADH1B were genes related to diffuse-type gastric cancer. We comprehensively validated the biological functions of the intestinal-type gastric cancer related gene UBE2C and evaluated its clinical significance on 1,868 cases of gastric cancer tissues from multiple medical centers of Shanghai, China. The gain of copy number on 20q was found in 4 out of 5 intestinal-type cancer cell lines, and no similar copy number variation (CNV) was found in any diffuse-type cancer cell line. Interfering UBE2C expression inhibited cell proliferation, migration and invasion in vitro, and tumorigenesis in vivo. Knockdown of UBE2C resulted in G2/M blockage in intestinal-type gastric cancer cells. Overexpression of UBE2C activated ERK signal pathway and promoted cancer cell proliferation. U0126, an inhibitor of ERK signaling pathway reversed the oncogenic phenotypes caused by UBE2C. Moreover, overexpression of UBE2C was identified in human intestinal-type gastric cancer. Overexpression of UBE2C protein predicted poor clinical outcome. Taken together, we characterized a group of Lauren classification-associated biomarkers, and clarified biological functions of UBE2C, an intestinal-type gastric cancer associated gene. Overexpression of UBE2C resulted in chromosomal instability that disturbed cell cycle and led to poor prognosis of intestinal-type gastric cancer.

A precision therapeutic strategy for hexokinase 1-null, hexokinase 2-positive cancers

Background

Precision medicine therapies require identification of unique molecular cancer characteristics. Hexokinase (HK) activity has been proposed as a therapeutic target; however, different hexokinase isoforms have not been well characterized as alternative targets. While HK2 is highly expressed in the majority of cancers, cancer subtypes with differential HK1 and HK2 expression have not been characterized for their sensitivities to HK2 silencing.

Methods

HK1 and HK2 expression in the Cancer Cell Line Encyclopedia dataset was analyzed. A doxycycline-inducible shRNA silencing system was used to examine the effect of HK2 knockdown in cultured cells and in xenograft models of HK1⁻HK2⁺ and HK1⁺HK2⁺ cancers. Glucose consumption and lactate production rates were measured to monitor HK activity in cell culture, and ¹⁸F-FDG PET/CT was used to monitor HK activity in xenograft tumors. A high-throughput screen was performed to search for synthetically lethal compounds in combination with HK2 inhibition in HK1⁻HK2⁺ liver cancer cells, and a combination therapy for liver cancers with this phenotype was developed. A metabolomic analysis was performed to examine changes in cellular energy levels and key metabolites in HK1⁻HK2⁺ cells treated with this combination therapy. The CRISPR Cas9 method was used to establish isogenic HK1⁺HK2⁺ and HK1⁻HK2⁺ cell lines to evaluate HK1⁻HK2⁺ cancer cell sensitivity to the combination therapy.

Results

Most tumors express both HK1 and HK2, and subsets of cancers from a wide variety of tissues of origin express only HK2. Unlike HK1⁺HK2⁺ cancers, HK1⁻HK2⁺ cancers are sensitive to HK2 silencing-induced cytostasis. Synthetic lethality was achieved in HK1⁻HK2⁺ liver cancer cells, by the combination of DPI, a mitochondrial complex I inhibitor, and HK2 inhibition, in HK1⁻HK2⁺ liver cancer cells. Perhexiline, a fatty acid oxidation inhibitor, further sensitizes HK1⁻HK2⁺ liver cancer cells to the complex I/HK2-targeted therapeutic combination. Although HK1⁺HK2⁺ lung cancer H460 cells are resistant to this therapeutic combination, isogenic HK1^KOHK2⁺ cells are sensitive to this therapy.

Conclusions

The HK1⁻HK2⁺ cancer subsets exist among a wide variety of cancer types. Selective inhibition of the HK1⁻HK2⁺ cancer cell-specific energy production pathways (HK2-driven glycolysis, oxidative phosphorylation and fatty acid oxidation), due to the unique presence of only the HK2 isoform, appears promising to treat HK1⁻HK2⁺ cancers. This therapeutic strategy will likely be tolerated by most normal tissues, where only HK1 is expressed.

Electronic supplementary material

The online version of this article (10.1186/s40170-018-0181-8) contains supplementary material, which is available to authorized users.

Targeting adenosine for cancer immunotherapy

Immune checkpoint antagonists (CTLA-4 and PD-1/PD-L1) and CAR T-cell therapies generate unparalleled durable responses in several cancers and have firmly established immunotherapy as a new pillar of cancer therapy. To extend the impact of immunotherapy to more patients and a broader range of cancers, targeting additional mechanisms of tumor immune evasion will be critical. Adenosine signaling has emerged as a key metabolic pathway that regulates tumor immunity. Adenosine is an immunosuppressive metabolite produced at high levels within the tumor microenvironment. Hypoxia, high cell turnover, and expression of CD39 and CD73 are important factors in adenosine production. Adenosine signaling through the A2a receptor expressed on immune cells potently dampens immune responses in inflamed tissues. In this article, we will describe the role of adenosine signaling in regulating tumor immunity, highlighting potential therapeutic targets in the pathway. We will also review preclinical data for each target and provide an update of current clinical activity within the field. Together, current data suggest that rational combination immunotherapy strategies that incorporate inhibitors of the hypoxia-CD39-CD73-A2aR pathway have great promise for further improving clinical outcomes in cancer patients.