Molecular regulatory network of PD-1/PD-L1 in non-small cell lung cancer

Genome-wide multimediator analyses using the generalized Berk-Jones statistics with the composite test

MOTIVATION

Mediation analysis is performed to evaluate the effects of a hypothetical causal mechanism that marks the progression from an exposure, through mediators, to an outcome. In the age of high-throughput technologies, it has become routine to assess numerous potential mechanisms at the genome or proteome scales. Alongside this, the necessity to address issues related to multiple testing has also arisen. In a sparse scenario where only a few genes or proteins are causally involved, conventional methods for assessing mediation effects lose statistical power because the composite null distribution behind this experiment cannot be attained. The power loss hence decreases the true mechanisms identified after multiple testing corrections. To fairly delineate a uniform distribution under the composite null, Huang (Genome-wide analyses of sparse mediation effects under composite null hypotheses. Ann Appl Stat 2019a;13:60-84; AoAS) proposed the composite test to provide adjusted P-values for single-mediator analyses.

RESULTS

Our contribution is to extend the method to multimediator analyses, which are commonly encountered in genomic studies and also flexible to various biological interests. Using the generalized Berk-Jones statistics with the composite test, we proposed a multivariate approach that favors dense and diverse mediation effects, a decorrelation approach that favors sparse and consistent effects, and a hybrid approach that captures the edges of both approaches. Our analysis suite has been implemented as an R package MACtest. The utility is demonstrated by analyzing the lung adenocarcinoma datasets from The Cancer Genome Atlas and Clinical Proteomic Tumor Analysis Consortium. We further investigate the genes and networks whose expression may be regulated by smoking-induced epigenetic aberrations.

AVAILABILITY AND IMPLEMENTATION

An R package MACtest is available on https://github.com/roqe/MACtest.

Fascaplysin Induces Apoptosis and Ferroptosis, and Enhances Anti-PD-1 Immunotherapy in Non-Small Cell Lung Cancer (NSCLC) by Promoting PD-L1 Expression

Fascaplysin is a natural product isolated from sponges with a wide range of anticancer activities. However, the mechanism of fascaplysin against NSCLC has not been clearly studied. In this study, fascaplysin was found to inhibit migration by regulating the wnt/β-catenin signaling pathway and reversing the epithelial-mesenchymal transition phenotype. Further research showed that the anti-NSCLC effect of fascaplysin was mainly through the induction of ferroptosis and apoptosis. Fascaplysin-induced ferroptosis in lung cancer cells, evidenced by increased levels of ROS and Fe²⁺ and downregulation of ferroptosis-associated protein and endoplasmic reticulum stress, was involved in fascaplysin-induced ferroptosis. In addition, ROS was found to mediate fascaplysin-induced apoptosis. Fascaplysin significantly upregulated the expression of PD-L1 in lung cancer cells, and enhanced anti-PD-1 antitumor efficacy in a syngeneic mouse model. Therefore, these results suggest that fascaplysin exerts anticancer effects by inducing apoptosis and ferroptosis in vitro, and improving the sensitivity of anti-PD-1 immunotherapy in vivo. Fascaplysin is a promising compound for the treatment of NSCLC.

Circular RNA circFOXO3 facilitate non-small cell lung cancer progression through upregulating HMGB3 via sponging miR-545-3p/miR-506-3p

PURPOSE

Circular RNAs (circRNAs) have emerged as a pivotal regulatory element in the progression of human cancers. Being an important member of circRNAs, circFOXO3 has been implicated in tumor invasion or metastasis of non-small cell lung cancer (NSCLC); however, the molecular mechanism underlying this promoting effect remains an enigma. The present study aims to study the function of circFOXO3 and dissect the relevant intracellular network in the progression and metastasis of NSCLC.

METHODS

Quantitative real time PCR (RT-qPCR) assay and Western blotting were used to quantify the levels of RNAs and proteins respectively. starBase v2.0 and luciferase assay were used to validate the target of circRNAs or miRNAs. Cell Counting Kit-8 (CCK-8) assay was adopted to examine cell viability. Transwell was used to determine cell invasion and migration. Xenograft model was established to detect tumor growth.

RESULTS

RT-qPCR showed that circFOXO3 was overexpressed in NSCLC cells and tissues. Knockdown of circFOXO3 not only inhibited NSCLC cell proliferation, migration and invasion in vitro but also suppressed tumor growth in vivo. starBase v2.0 and luciferase assay results collectively suggested that circFOXO3 sponged miR-545-3p and miR-506-3p. Dual-inhibition of circFOXO3 and its target miRNAs suppressed the reduction of cell proliferation, migration and invasion induced by siRNA of circFOXO3 (si-circFOXO3), demonstrating that the effect of circFOXO3 on NSCLC was dependent on sponging miR-545-3p and miR-506-3p. Further bioinformatic analysis and biochemistry experiments revealed that miR-545-3p and miR-506-3p regulated the expression of a family member of high-mobility group box, HMGB3.

CONCLUSION

Here, we show thatcircFOXO3 in NSCLC promotes the proliferation, migration and invasion of NSCLC cells, thereby promoting tumor growth. We further find that circFOXO3 sponges miR-545-3p/miR-506-3p that bind to 3'-UTR of HMGB3 mRNA, which constitutes the major network fulfilling the circFOXO3's promoting effect. Therefore, we proposed that circFOXO3 could be a potential therapeutic target for NSCLC.

Prognostic prospect of soluble programmed cell death ligand-1 in cancer management

Aggressive tissue biopsy is commonly unavoidable in the management of most suspected tumor cases to conclusively verify the presence of cancerous cells through histological assessment. The extracted tissue is also immunostained for detection of antigens (tissue tumor markers) of potential prognostic or therapeutic importance to assist in treatment decision. Although liquid biopsies can be a powerful tool for monitoring treatment response, they are still excluded from standard cancer diagnostics, and their utility is still being debated in the scientific community. With a myriad of soluble tissue tumor markers now being discovered, liquid biopsies could completely change the current paradigms of cancer management. Recently, soluble programmed cell death ligand-1 (sPD-L1), which is found in the peripheral blood, i.e. serum and plasma, has shown potential as a pre-therapeutic predictive marker as well as a prognostic biomarker to monitor treatment efficacy. Thus, this review focuses on the emergence of sPD-L1 and promising technologies for its detection in order to support liquid biopsies for future cancer management.

Colorectal Cancer, Liver Metastases and Biotherapies

(1) Background: colorectal cancer (CRC) is one of the deadliest causes of death by cancer worldwide. Its first main metastatic diffusion spreads to the liver. Different mechanisms such as the epithelial-mesenchymal transition and angiogenesis are the characteristics of this invasion. At this stage, different options are possible and still in debate, especially regarding the use of targeted therapeutics and biotherapies. (2) Methods: A review of the literature has been done focusing on the clinical management of liver metastasis of colorectal cancer and the contribution of biotherapies in this field. (3) Results: In a clinical setting, surgeons and oncologists consider liver metastasis in CRC into two groups to launch adapted therapeutics: resectable and non-resectable. Around these two entities, the combination of targeted therapies and biotherapies are of high interest and are currently tested to know in which molecular and clinical conditions they have to be applied to impact positively both on survival and quality of life of patients.

Clinical Relevance of PD-L1 Expression and CD8+ T Cells' Infiltration in Patients With Lung Invasive Mucinous Adenocarcinoma

BACKGROUND

Invasive mucinous adenocarcinoma (IMA) of the lung is a rare and distinct subtype of adenocarcinoma. At present, people have no idea whether IMA patients can benefit from immunotherapy and target therapy; thus there is an urgent need to clarify the immune microenvironment and genetic characteristics of this cohort.

METHODS

A total of 31 IMA patients matched with 27 non-mucinous adenocarcinoma (non-IMA) patients were enrolled in this study, and clinical data was collected. The expression of PD-L1, CD8+ tumor-infiltrating lymphocytes (TILs) and ALK was determined by immunohistochemistry. Polymerase Chain Reaction was used to determine the mutations of EGFR. The Chi-square test, Kaplan-Meier method and Cox proportional hazard regression model were used to explore the correlations between these clinicopathological variables, survival and identify risk factors.

RESULTS

Of the patients with IMA 9.7% (3/31) revealed positive PD-L1 expression and 35.5% (11/31) showed CD8+ TIL infiltration, which were markedly lower than that of non-IMA group [PD-L1: 48.1% (13/27); CD8: 81.5% (22/27)]. Moreover, five (16.1%) patients in IMA group and 10 (37.0%) patients in non-IMA group had EGFR mutations, and nine (29.0%) patients in IMA group and zero (0.0%) patient in non-IMA group had ALK rearrangements. Additionally, we observed that IMA patients with CD8+ TIL infiltration had a worse prognosis than CD8-negative group (P = 0.024). Multivariate analyses showed that CD8 was an independent prognostic factor for patient's survival (HR = 5.60, 95% CI: 1.35-23.22, P = 0.017).

CONCLUSION

Patients with IMA have down-regulated expression of PD-L1 and less CD8+ TIL infiltration in tumor microenvironment. Besides, a lower frequency of EGFR mutations was detected in patients with IMA than non-IMA patients while a higher rate of ALK rearrangements was found. Our results provide important reference for therapy of lung IMA.

Emerging Role of Immunotherapy for Colorectal Cancer with Liver Metastasis

Colorectal cancer (CRC) is the third most common malignant tumor in the world and the second leading cause of cancer-related deaths, with the liver as the most common site of distant metastasis. The prognosis of CRC with liver metastasis is poor, and most patients cannot undergo surgery. In addition, conventional antitumor approaches such as chemotherapy, radiotherapy, targeted therapy, and surgery result in unsatisfactory outcomes. In recent years, immunotherapy has shown good prospects in the treatment of assorted tumors by enhancing the host's antitumor immune function, and it may become a new effective treatment for liver metastasis of CRC. However, challenges remain in applying immunotherapy to CRC with liver metastasis. This review examines how the microenvironment and immunosuppressive landscape of the liver favor tumor progression. It also highlights the latest research advances in immunotherapy for colorectal liver metastasis and identifies immunotherapy as a treatment regimen with a promising future in clinical applications.

HDAC10 Is Positively Associated With PD-L1 Expression and Poor Prognosis in Patients With NSCLC

Currently, non-small cell lung carcinoma (NSCLC) is a major worldwide health problem. Meanwhile accumulating evidence indicates that histone deacetylase (HDAC) activation could induce PD-L1 expression in various types of cancer, especially in myeloma and B-cell lymphomas. Therefore, we hypothesized that high-level expression of HDAC10 is associated with PD-L1 induction and poor prognosis in patients with NSCLC. In total 180 NSCLC patients receiving complete pulmonary resection and systematic lymph node dissection were enrolled from April 2004 to August 2009. The patients with integrated clinicopathological records were followed up. The expression level of HDAC10 and PD-L1 in tissue samples was determined by immunohistochemistry. We observed that HDAC10 expression in lung cancer tissue is significantly higher than that in corresponding para-cancer tissue. Moreover, HDAC10 expression positively correlated with the expression level of PD-L1 (r = 0.213, P < 0.05) in NSCLC patients. Subgroup, multivariate analysis showed that the expression level of HDAC10 can be an independent prognostic factor and high-level expression of HDAC10 indicated poor overall survival for pulmonary carcinoma (r = 0.540, P < 0.001). Our findings suggest that the expression level of HDAC10 is positively associated with PD-L1 expression and may predict the outcome of patients with NSCLC.