ThPOK inhibits the immune escape of gastric cancer cells by inducing STPG1 to inactivate the ERK pathway

Background

Gastric cancer is the second most frequently diagnosed cancer worldwide. Weak immunogenicity helps cancer cells escape from immune elimination and grow into predominant subpopulations. This study aimed to investigate the effect of Zinc finger and BTB domain containing 7B (Zbtb7b, Alias ThPOK) on T cell activation after coculture with gastric cancer cells.

Methods

Cell Counting Kit-8 assay (CCK-8) was performed to explore the viability of gastric cancer cells. Flow cytometry analysis was used to measure CD3+ T cell proliferation and the ratio of activated IFN-γ+ T cells which were co-incubated with gastric cancer cells (HGC-27, SNU-1). The binding between ThPOK and the promoter of its target sperm tail PG-rich repeat containing 1 (STPG1) was explored using ChIP and luciferase reporter assays. Relative gene expression was quantified using RT-qPCR.

Results

ThPOK was expressed at a low level in gastric cancer tissues and cells at mRNA and protein levels. Gastric cancer patients with lower ThPOK expression had poorer prognosis. ThPOK overexpression suppressed gastric cancer cell viability and increased T cell activation. ThPOK served as a transcription factor for STPG1. STPG1 expression was also at a low level in the tissues and cells of gastric cancer. ThPOK positively regulated the mRNA and protein levels of STPG1 in gastric cancer cells. Moreover, ThPOK was demonstrated to bind with STPG1 promoter. STPG1 upregulation also exerted inhibitory effects on gastric cancer cell viability and T cell activation. Additionally, ThPOK and STPG1 were revealed to inactivate the ERK pathway in gastric cancer cells.

Conclusion

ThPOK inhibits gastric cancer cell viability and increases T cell activation by inducing STPG1 to inactivate the ERK pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-022-00485-5.

The allocation of COVID-19 vaccines and antivirals against emerging SARS-CoV-2 variants of concern in East Asia and Pacific region: A modelling study

BACKGROUND

In view of emerging variants of concern (VOCs), we aimed to evaluate the impact of various allocation strategies of COVID-19 vaccines and antiviral such that the pandemic exit strategy could be tailored to risks and preferences of jurisdictions in the East Asia and Pacific region (EAP) to improve its efficiency and effectiveness.

METHODS

Vaccine efficacies were estimated from the titre distributions of 50% plaque reduction neutralization test (PRNT50), assuming that PRNT50 titres of primary vaccination decreased by 2-10 folds due to antibody waning and emergence of VOCs, and an additional dose of vaccine would increase PRNT50 titres by 3- or 9-fold. We then used an existing SARS-CoV-2 transmission model to assess the outcomes of vaccine allocation strategies with and without the use of antivirals for symptomatic patients in Japan, Hong Kong, and Vietnam.

FINDINGS

Increasing primary vaccination coverage was the most important contributing factor in reducing the total and peak number of COVID-19 hospitalisations, especially when population vaccine coverage or vaccine uptake among older adults was low. Providing antivirals to 50% of symptomatic infections only further reduced total and peak hospitalisations by 10-13%. The effectiveness of an additional dose of vaccine was highly dependent on the immune escape potential of VOCs and antibody waning, but less dependent on the boosting efficacy of the additional dose.

INTERPRETATION

Increasing primary vaccination coverage should be prioritised in the design of allocation strategies of COVID-19 vaccines and antivirals against emerging VOCs, such as Omicron, in the EAP region. Heterologous vaccination with any available vaccine as the additional dose could be considered when planning pandemic exit strategies tailored to the circumstances of EAP jurisdictions.

FUNDING

Health and Medical Research Fund, General Research Fund, AIR@InnoHK.

Upregulated LINC01088 facilitates malignant phenotypes and immune escape of colorectal cancer by regulating microRNAs/G3BP1/PD-L1 axis

PURPOSE

Long intergenic non-coding RNA LINC01088 is a newly discovered long non-coding RNA (lncRNA). Its biological function in colorectal cancer (CRC) remains unknown.

METHODS

Here, 36 paired CRC and para-cancerous tissues were collected. In vitro, fluorescence in situ hybridization (FISH) assay, qPCR, western blotting analysis and cellular functional experiments, RNA immunoprecipitation (RIP) assay and dual-luciferase reporter system analysis were performed. In vivo, xenograft tumor mouse models were generated. Besides, patient-derived intestinal organoid (PDO) was generated ex vivo.

RESULTS

We found that LINC01088 was significantly upregulated in colorectal cancer tissues and CRC cell lines compared to adjacent normal tissues and colonic epithelial cells. High LINC01088 levels were correlated with adverse outcomes in patients with CRC. LINC01088 was mainly located in the cytoplasm. LINC01088 knockdown suppressed the proliferation, migration, invasion, and immune escape of colorectal cancer cells. Mechanistically, LINC01088 bound directly to miR-548b-5p and miR-548c-5p that were significantly upregulated Ras GTPase-activating protein-binding proteins 1 (G3BP1) and programmed death ligand 1 (PD-L1) expression, altering CRC cell phenotypes. In mouse xenograft models, LINC01088 knockdown restrained CRC tumor growth and lung metastasis. Furthermore, G3BP1 overexpression reversed LINC01088-knockdown-mediated inhibitory effects on tumor growth. Notably, LINC01088 knockdown downregulated PD-L1 expression, while G3BP1 overexpression restored PD-L1 expression in xenograft tumors. Besides, LINC01088 knockdown repressed CRC organoid growth ex vivo.

CONCLUSION

Overall, these findings suggested that LINC01088 directly targeted miR-548b-5p and miR-548c-5p, promoting G3BP1 and PD-L1 expression, which facilitated colorectal cancer progression and immune escape.

Estradiol initiates the immune escape of non-small cell lung cancer cells via ERβ/SIRT1/FOXO3a/PD-L1 axis

Mounting evidence has postulated estrogen as a contributor for lung cancer development and progression. Here, we focused on the effect of estradiol (E2) on the immune escape of non-small cell lung cancer (NSCLC). The expression of FOXO3a in NSCLC samples was screened by gene microarray and then verified using Western blot analysis in NSCLC cell lines. Interaction between E2, SIRT1, FOXO3a and PD-L1 was determined. Following ectopic expression and depletion experiments in A549 and H1435 cells, cell proliferation and killing of cytotoxic T lymphocytes (CTLs) on NSCLC cells were evaluated. Xenograft mouse models were prepared to validate the in vivo effect of E2. E2 activated SIRT1 by up-regulating the expression of ERβ and thereby weakened the killing of CTLs on NSCLC cells. E2 elevated PD-L1 by up-regulating the ERβ/SIRT1 axis to promote the immune escape of NSCLC cells. SIRT1 degraded FOXO3a by reducing the acetylation level of FOXO3a and increased its ubiquitination. E2 inhibited the expression of FOXO3a and elevated PD-L1 expression, thereby promoting the immune escape of NSCLC cells. In vivo results showed that E2 facilitated the growth and metastasis of NSCLC cells in nude mice by elevating ERβ via SIRT1/FOXO3a/PD-L1 axis. In summary, our data revealed the critical roles of E2/ERβ/SIRT1/FOXO3a/PD-L1 axis in the immune escape of NSCLC cells and suggested that the axis may be promising therapeutic targets for NSCLC.

The repeated setbacks of HIV vaccine development laid the groundwork for SARS-CoV-2 vaccines

The decades-long effort to produce a workable HIV vaccine has hardly been a waste of public and private resources. To the contrary, the scientific know-how acquired along the way has served as the critical foundation for the development of vaccines against the novel, pandemic SARS-CoV-2 virus. We retell the real-world story of HIV vaccine research – with all its false leads and missteps – in a way that sheds light on the current state of the art of antiviral vaccines. We find that HIV-related R&D had more than a general spillover effect. In fact, the repeated failures of phase 2 and 3 clinical trials of HIV vaccine candidates have served as a critical stimulus to the development of successful vaccine technologies today. We rebut the counterargument that HIV vaccine development has been no more than a blind alley, and that recently developed vaccines against COVID-19 are really descendants of successful vaccines against Ebola, MERS, and SARS. These successful vaccines likewise owe much to the vicissitudes of HIV vaccine development. We then discuss how the failures of HIV vaccine development have taught us how adapt SARS-CoV-2 vaccines to immune escape from emerging variants. Finally, we inquire whether recent advances in the development of vaccines against SARS-CoV-2 might in turn further the development of an HIV vaccine - what we describe as a reverse spillover effect.

Comparative transcriptome analysis reveals potential anti-viral immune pathways of turbot (Scophthalmus maximus) subverted by megalocytivirus RBIV-C1 for immune evasion

Successful viral infection and multiplication chiefly rely on virus subversion mechanisms against host anti-viral immune responses. In this study, in order to reveal the anti-viral immune-related pathways suppressed by megalocytivirus infection, transcriptome analysis was performed on the head-kidney of turbot (Scophthalmus maximus) infected with lethal dose of RBIV-C1 at 3, 6 and 9 days post challenge (dpc). The results showed that, compared to unchallenged groups, 190, 1220, and 3963 DEGs were detected in RBIV-C1 infected groups at 3, 6 and 9 dpc, respectively, of which, DEGs of complement components and pattern recognition proteins were up-regulated at 3 dpc and down-regulated at 6 and 9 dpc, DEGs of cytokines were up-regulated at 6 dpc and down-regulated at 9 dpc. Expression trend analysis revealed that DEGs of profiles 9 and 13 featured decreased expression patterns and were significantly enriched into 10 immune-related pathways, i.e., complement and coagulation cascades, cytokine-cytokine receptor interaction, chemokine signaling pathway, B/T cell receptor signaling pathway, antigen processing and presentation, and so on. Further co-expression network analysis (WGCNA) revealed positive correlated innate immune related pathways at 3 and 6 dpc, and negative correlated innate and adaptive immune related pathways at 9 dpc. This study revealed a set of anti-viral immune genes/pathways that would also be potential targets subverted by RBIV-C1 for immune evasion, which can serve as a valuable resource for future studies on the molecular mechanisms of anti-viral immune defense of turbot and immune escape of megalocytivirus.

Emergence of a recurrent insertion in the N-terminal domain of the SARS-CoV-2 spike glycoprotein

Tracking the evolution of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through genomic surveillance programs is undoubtedly one of the key priorities in the current pandemic situation. Although the genome of SARS-CoV-2 acquires mutations at a slower rate compared with other RNA viruses, evolutionary pressures derived from the widespread circulation of SARS-CoV-2 in the human population have progressively favored the global emergence, though natural selection, of several variants of concern that carry multiple non-synonymous mutations in the spike glycoprotein. These are often placed in key sites within major antibody epitopes and may therefore confer resistance to neutralizing antibodies, leading to partial immune escape, or otherwise compensate infectivity deficits associated with other non-synonymous substitutions. As previously shown by other authors, several emerging variants carry recurrent deletion regions (RDRs) that display a partial overlap with antibody epitopes located in the spike N-terminal domain (NTD). Comparatively, very little attention had been directed towards spike insertion mutations prior to the emergence of the B.1.1.529 (omicron) lineage. This manuscript describes a single recurrent insertion region (RIR1) in the N-terminal domain of SARS-CoV-2 spike protein, characterized by at least 49 independent acquisitions of 1-8 additional codons between Val213 and Leu216 in different viral lineages. Even though RIR1 is unlikely to confer antibody escape, its association with two distinct formerly widespread lineages (A.2.5 and B.1.214.2), with the quickly spreading omicron and with other VOCs and VOIs warrants further investigation concerning its effects on spike structure and viral infectivity.

SNF5, a core subunit of SWI/SNF complex, regulates melanoma cancer cell growth, metastasis, and immune escape in response to matrix stiffness

Increased stiffness of the extracellular matrix is an important hallmark of melanoma development and progression, but its regulatory role and related mechanisms remain unclear. We adapted polydimethylsiloxane (PDMS)-micropillar-based matrix platform and investigated the effect of matrix stiffness on the proliferation, epithelial-mesenchymal transition (EMT), and immune escape of melanoma cells. We observed a stiff matrix enhanced cell proliferation, EMT, and immune escape of A375 cells. Furthermore, the expression of SNF5 on the stiffer matrix was higher than that on the softer matrix. Next, we investigated whether SNF5 is an important transducer in response to matrix stiffness. Our results revealed that knockdown of SNF5 significantly decreased stiff matrix-induced activation of cell proliferation, EMT and immune escape. Meanwhile, the overexpression of SNF5 showed its ability to increase cell proliferation, invasion and immune escape by activating the STAT-3 pathway in vitro. Furthermore, SNF5 deficiency elevated the level of tumor-infiltrating CD8+T cells and decreased the number of PD-L1 positive cells in vivo. Together, our findings suggested that stiffer substrate enhanced melanoma development by upregulating SNF5 expression, and SNF5 is a key mediator of stiffer matrix-induced immune evasion of melanoma cancer cells.

Tumor promoting effect of circ_002172 associates with induced immune escape in breast cancer via the miR-296-5p/CXCL12 axis

Comprehending the biology of tumorigenesis needs identification of determinants of the immune reaction during cancer development. This study intends to illustrate the mechanistic actions of a bioinformatically predicted circRNA circ_002172 in cytotoxic T lymphocytes (CTL) infiltration and escape of breast cancer (BC) from immunological destruction. Expression patterns of circ_002172, miR-296-5p, and CXCL12 were determined in BC tissues and cells. Effects of circ_002172, miR-296-5p, and CXCL12 on cell viability, migration, and invasion were examined through artificial modulation of their expression. The role of circ_002172 and CXCL12 on tumorigenesis was validated in subcutaneously transplanted and orthotopically transplanted tumors in nude mice. Upregulation of circ_002172 and CXCL12 and downregulation of miR-296-5p occurred in BC tissues and cells. Circ_002172 promoted the oncogenic phenotypes of BC cells in vitro and growth of tumors in vivo, which was reversed by knockdown of CXCL12 expression. Circ_002172, as a miR-296-5p sponge, upregulated expression CXCL12. Moreover, Ectopic expression of circ_002172 inhibited cytotoxic T lymphocytes (CTL) infiltration to promote the immune escape of BC. In conclusion, the tumor-promoting role of circ_002172 in BC was achieved by inducing immune escape via the miR-296-5p/CXCL12 axis.

The acidic tumour microenvironment: Manipulating the immune response to elicit escape

The success of cancer treatment relies on the composition of the tumour microenvironment which is comprised of tumour cells, blood vessels, stromal cells, immune cells, and extracellular matrix components. Barriers to effective cancer treatment need to be overcome, and the acidic microenvironment of the tumour provides a key target for treatment. This review intends to provide an overview of the effects that low extracellular pH has on components of the tumour microenvironment and how they contribute to immune escape. Further, potential therapeutic targets will be discussed.

Deciphering mechanisms of immune escape to inform immunotherapeutic strategies in multiple myeloma

Multiple myeloma is an incurable cancer characterized by the uncontrolled growth of malignant plasma cells nurtured within a permissive bone marrow microenvironment. While patients mount numerous adaptive immune responses directed against their disease, emerging data demonstrate that tumor intrinsic and extrinsic mechanisms allow myeloma cells to subvert host immunosurveillance and resist current therapeutic strategies. Myeloma downregulates antigens recognized by cellular immunity and modulates the bone marrow microenvironment to promote uncontrolled tumor proliferation, apoptotic resistance, and further hamper anti-tumor immunity. Additional resistance often develops after an initial clinical response to small molecules, immune-targeting antibodies, immune checkpoint blockade or cellular immunotherapy. Profound quantitative and qualitative dysfunction of numerous immune effector cell types that confer anti-myeloma immunity further supports myelomagenesis, disease progression and the emergence of drug resistance. Identification of tumor intrinsic and extrinsic resistance mechanisms may direct the design of rationally-designed drug combinations that prevent or overcome drug resistance to improve patient survival. Here, we summarize various mechanisms of immune escape as a means to inform novel strategies that may restore and improve host anti-myeloma immunity.

Specific targeting of cancer stem cells by immunotherapy: A possible stratagem to restrain cancer recurrence and metastasis

Cancer stem cells (CSCs), the tumor-initiating cells playing a crucial role in cancer progression, recurrence, and metastasis, have the intrinsic property of self-renewal and therapy resistance. The tumorigenic properties of these cells include generation of cellular heterogeneity and immuno-suppressive tumor microenvironment (TME), conferring them the capability to resist a variety of anti-cancer therapeutics. Further, CSCs possess several unique immunological properties that help them escape recognition by the innate and adaptive immune system and shape a TME into a pro-tumorigenic and immunosuppressive landscape. In this context, immunotherapy is considered one of the best therapeutic options for eliminating CSCs to halt cancer recurrence and metastasis. In this review, we discuss the various immunomodulatory properties of CSCs and the interaction of CSCs with the immune system enabling immune evasion. In addition, we also highlight the present research update on immunotherapeutic targeting of CSCs and the possible further scope of research on this topic. We believe that a deeper understanding of CSCs' immunological properties and the crosstalk between CSCs and the immune system can develop better innovative immune-therapeutics and enhance the efficacy of current therapy-resistant cancer treatments.

Abrogation of HnRNP L enhances anti-PD-1 therapy efficacy via diminishing PD-L1 and promoting CD8+ T cell-mediated ferroptosis in castration-resistant prostate cancer

Owing to incurable castration-resistant prostate cancer (CRPC) ultimately developing after treating with androgen deprivation therapy (ADT), it is vital to devise new therapeutic strategies to treat CRPC. Treatments that target programmed cell death protein 1 (PD-1) and programmed death ligand-1 (PD-L1) have been approved for human cancers with clinical benefit. However, many patients, especially prostate cancer, fail to respond to anti-PD-1/PD-L1 treatment, so it is an urgent need to seek a support strategy for improving the traditional PD-1/PD-L1 targeting immunotherapy. In the present study, analyzing the data from our prostate cancer tissue microarray, we found that PD-L1 expression was positively correlated with the expression of heterogeneous nuclear ribonucleoprotein L (HnRNP L). Hence, we further investigated the potential role of HnRNP L on the PD-L1 expression, the sensitivity of cancer cells to T-cell killing and the synergistic effect with anti-PD-1 therapy in CRPC. Indeed, HnRNP L knockdown effectively decreased PD-L1 expression and recovered the sensitivity of cancer cells to T-cell killing in vitro and in vivo, on the contrary, HnRNP L overexpression led to the opposite effect in CRPC cells. In addition, consistent with the previous study, we revealed that ferroptosis played a critical role in T-cell-induced cancer cell death, and HnRNP L promoted the cancer immune escape partly through targeting YY1/PD-L1 axis and inhibiting ferroptosis in CRPC cells. Furthermore, HnRNP L knockdown enhanced antitumor immunity by recruiting infiltrating CD8⁺ T cells and synergized with anti-PD-1 therapy in CRPC tumors. This study provided biological evidence that HnRNP L knockdown might be a novel therapeutic agent in PD-L1/PD-1 blockade strategy that enhanced anti-tumor immune response in CRPC.

NLRP3 promotes immune escape by regulating immune checkpoints: A pan-cancer analysis

NLRP3 plays a pathogenic role in tumorigenesis by regulating innate and acquired immunity, apoptosis, differentiation, and intestinal microbes in tumors. Our research aimed to investigate the role of NLRP3 in pan-cancers based on multi-omics data in the TCGA database. Most types of tumors showed increased expression of NLRP3. Among them, the overexpressed NLRP3 in liver hepatocellular carcinoma (LIHC) and ovarian cancer (OV) indicated worse overall survival (OS). Further analysis also confirmed overexpressed NLRP3 in colon cancer (COAD) indicated a high probability of microsatellite instability (MSI) and low tumor mutational burden (TMB), which indicated a better response to immune checkpoint inhibitors (ICIs). Interestingly, overexpression of NLRP3 was closely related to high infiltration of immune cells (T cells, B cells, etc.) and overexpressed immune checkpoints (PD-1, PD-L1, LAG3, etc.). These results demonstrated NLRP3 promoted immune escape in cancers. Finally, we investigated the expression of various immune checkpoints by treating NLRP3 inhibitor MCC950 during the co-culture of peripheral blood mononuclear cells (PBMC) and LIHC cell line Hep3B. MCC950 significantly repressed the expression of PD-L1 and LAG3, and promoted the apoptosis rate of Hep3B. In conclusion, our research demonstrated the role of NLRP3 in pan-cancer, especially in LIHC. Inhibition of NLRP3 promoted the killing effect of T cells to cancer cells by repressing the expression of immune checkpoints.

Urogenital Microbiota:Potentially Important Determinant of PD-L1 Expression in Male Patients with Non-muscle Invasive Bladder Cancer

Background

Urogenital microbiota may be associated with the recurrence of bladder cancer, but the underlying mechanism remains unclear. The notion that microbiota can upregulate PD-L1 expression in certain epithelial tumors to promote immune escape has been demonstrated. Thus, we hypothesized that the urogenital microbiota may be involved in the recurrence and progression of non-muscle invasive bladder cancer (NMIBC) by upregulating the PD-L1 expression. To test this hypothesis, we investigated the relationship between urogenital microbial community and PD-L1 expression in male patients with NMIBC.

Results

16S rRNA gene sequencing was performed to analyse the composition of urogenital microbiota, and the expression of PD-L1 in cancerous tissues was detected by immunohistochemistry. The subjects (aged 43–79 years) were divided into PD-L1-positive group (Group P, n = 9) and PD-L1-negative group (Group N, n = 19) respectively based on their PD-L1 immunohistochemical results. No statistically significant differences were found in the demographic characteristics between group P and N. We observed that group P exhibited higher species richness (based on Observed species and Ace index, both P < 0.05). Furthermore, subgroup analysis showed that the increase in number of PD-L1 positive cells was accompanied by increased richness of urogenital microbiota. Significantly different composition of urogenital microbiota was found between group P and group N (based on weighted Unifrac and unweighted Unifrac distances metric, both P < 0.05). Enrichment of some bacterial genera (e.g., Leptotrichia, Roseomonas, and Propionibacterium) and decrease of some bacterial genera (e.g., Prevotella and Massilia) were observed in group P as compared with group N. These findings indicated that these genera may affect the expression of PD-L1 through some mechanisms to be studied.

Conclusion

Our study provided for the first time an overview of the association between urogenital microbiota and PD-L1 expression in male patients with NMIBC, indicating that urogenital microbiota was an important determinant of PD-L1 expression in male NMIBC patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02407-8.

AKT Isoforms as a Target in Cancer and Immunotherapy

Over the past years, targeted therapies have received tremendous attention in cancer therapy. One of the most frequently targeted pathways is the PI3K/AKT/mTOR signaling pathway that regulates crucial cellular processes including proliferation, survival, and migration. In a wide variety of cancer entities, the PI3K/AKT/mTOR signaling pathway was found to be a critical driver of disease progression, indicating a noteworthy target in cancer therapy. This chapter focuses on targeted therapies against AKT, which is a key enzyme within the PI3K/AKT/mTOR pathway. Although the three different isoforms of AKT, namely AKT1, AKT2, and AKT3, have a high homology, the isoforms exhibit different biological functions. Recently, direct inhibitors against all AKT isoforms as well as selective inhibitors against specific AKT isoforms have been extensively investigated in preclinical work as well as in clinical trials to attenuate proliferation of cancer cells. While no AKT inhibitor has been approved by the FDA for cancer therapy to date, AKT still plays a crucial role in a variety of treatment strategies including immune checkpoint inhibition. In this chapter, we summarize the status of AKT inhibitors either targeting all or specific AKT isoforms. Furthermore, we explain the role of AKT signaling in direct inhibition of tumor cell growth as well as in immune cells and immune checkpoint inhibition.

Organoid Co-culture Methods to Capture Cancer Cell-Natural Killer Cell Interactions

Metastasis is a complex process that has been historically difficult to model in culture. Host immune responses play critical roles in restraining and promoting metastatic tumor cells. Here we describe a method of 3D organotypic co-culture of natural killer cells and tumor organoids to capture interactions between the two cellular populations. These assays can be used to model key aspects of metastatic biology and to screen for the effectiveness of agents that stimulate natural killer cell cytotoxicity.

High concentration of Dezocine induces immune escape of lung cancer and promotes glucose metabolism through up-regulating PD-L1 and activating NF-κB pathway

BACKGROUND

Dezocine is an opioid analgesic that can affect the immune system. Here, we explored the synergy of high concentration of Dezocine and Programmed death-ligand 1 (PD-L1) with regards to immune escape and glucose metabolism in lung cancer (LC).

METHODS

PD-L1 level in human LC cell lines was determined and the influence of Dezocine at different concentrations for the proliferation of LC cells was identified. Next, LC cells were transfected to alter PD-L1 level, and exposed to Dezocine at 8 μg/mL to explore their effects on cell proliferation, production of interferon-γ (IFN-γ), contents of glucose, lactate and NADPH/NADP+ and activation of the nuclear factor-κB (NF-κB) pathway.

RESULTS

PD-L1 level was increased in LC cells and Dezocine (8 μg/mL) impaired the proliferation of LC cells. Down-regulating PD-L1 inhibited cell proliferation, enhanced production of IFN-γ and reduced the contents of glucose, lactate and NADPH/NADP+ while up-regulating PD-L1 caused the opposite results. Dezocine (8 μg/mL) induced immune escape and glucose metabolism in LC, and Dezocine-induced effects were reversed by down-regulating PD-L1. Dezocine (8 μg/mL) up-regulated PD-L1 by activating the NF-κB pathway.

CONCLUSION

Dezocine at 8 μg/mL promotes immune escape and glucose metabolism in LC through up-regulating PD-L1 and activating the NF-κB pathway.

[Perspectives for the evolution and use of CAR-T cells]

CAR-T cells have recently made a stunning entry on the arena of immunotherapy of B-cell lymphomas. This new treatment approach represents the culmination of 30 years of efforts to understand the role of T cells in the antitumor response. However, this technology is still in its infancy and suffers from a number of limitations. Many areas for improvement, based in particular on the possibilities of additional genetic manipulations of CAR-T cells, aim at reducing their toxicity, increasing their persistence in vivo, preventing the risk of tumor escape, recruiting other immune effectors, or extending their application to other cancers. Further studies of the dynamic interaction between the patient and these live drugs will allow elucidating the mechanisms determining the antitumor response in this context and thus developing more efficiently the future CAR-T cells.

Role of immune escape in different digestive tumours

A counterbalance between immune cells and tumour cells is key to fighting tumours, and immune escape is an important mechanism for the survival of tumour cells in the body. Tumor cells and their cytokines impair the activity of T cells, NK cells, macrophages and other immune cells through various ways, and change the expression of their own surface antigens so as to avoid the clearance of the immune system. Changes in major histocompatibility complex molecules, high expression of programmed death-ligand 1, and the presence of immunosuppressive cells in the tumor microenvironment (TME) are main means by which tumors impair the function of immune cells. During the development of tumours of the digestive system, different mechanisms acting on tumour cells, the TME, and immune cells lead to immune escape and promote tumour progression. In this paper, the mechanisms of immune escape in tumour cells of the digestive system are reviewed to provide a theoretical basis for the immunotherapy of gastrointestinal tumours.

LncRNA LINC00184 promotes docetaxel resistance and immune escape via miR-105-5p/PD-L1 axis in prostate cancer

BACKGROUND

Docetaxel (DTX) resistance is a common factor in metastatic prostate cancer (PC) chemotherapy that leads to treatment failure. Because lncRNA is involved in a variety of regulatory processes in tumor progression, this study aimed to explore the function and mechanism of LINC00184 in docetaxel resistance of PC.

METHODS

Two PC cell lines and their docetaxel resistant cell lines (DU145/DTX and PC3/DTX) were used. The expression of LINC00184 in both cell lines and PC patient samples were evaluated. SiRNA knocking down was used to test the function of LINC00184 in proliferation and colony formation. Interaction between LINC00184 and its target miR-105-5p, as well as miR-105-5p and PD-L1 was checked by luciferase reporter assay and RNA pull-down assay. PC cell line and CD8 + T cell co-culture system was established, miR-105-5p inhibitor was co-transfected with LINC00184 siRNA to investigate the underline mechanism.

RESULTS

LINC00184 was found to be associated with docetaxel resistance and adverse prognosis of prostate cancer. It regulated docetaxel resistance and T-cell-mediated immune response in prostate cancer cells. LINC00184 was induced by adsorption of miR-105-5p and negatively regulated it, subsequently inhibited the expression level of PD-L1.

CONCLUSIONS

LINC00184 promoted docetaxel resistance and immune escape in prostate cancer cells by adsorption of miR-105-5p, resulted in upregulation of the expression of PD-L1. LINC00184 could possibly be considered as a potential target for treatment in prostate cancer patients with docetaxel-resistance.

Reduced neutralization of SARS-CoV-2 B.1.617 variant by convalescent and vaccinated sera

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The Spike protein that mediates coronavirus entry into host cells is a major target for COVID-19 vaccines and antibody therapeutics. However, multiple variants of SARS-CoV-2 have emerged, which may potentially compromise vaccine effectiveness. Using a pseudovirus-based assay, we evaluated SARS-CoV-2 cell entry mediated by the viral Spike B.1.617 and B.1.1.7 variants. We also compared the neutralization ability of monoclonal antibodies from convalescent sera and neutralizing antibodies (NAbs) elicited by CoronaVac (inactivated vaccine) and ZF2001 (RBD-subunit vaccine) against B.1.617 and B.1.1.7 variants. Our results showed that, compared to D614G and B.1.1.7 variants, B.1.617 shows enhanced viral entry and membrane fusion, as well as more resistant to antibody neutralization. These findings have important implications for understanding viral infectivity and for immunization policy against SARS-CoV-2 variants.

Shuyu pills inhibit immune escape and enhance chemosensitization in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is characterized by dysregulation of the immune microenvironment and the development of chemoresistance. Specifically, expression of the programmed cell death protein 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) axis, an immune checkpoint, may lead to tumour immune escape, resulting in disease progression. The latest research shows that tumour immune escape may be caused by the upregulation of PD-L1 mediated by hypoxia-inducible factor-1 alpha (HIF-1α), and simultaneous inhibition of HIF-1α and PD-L1 has the potential to enhance the host’s antitumour immunity. Moreover, inhibition of the PD-1/PD-L1 axis may mitigate tumour chemoresistance. Shuyu pills (SYPs) contain immunity-enhancing and antitumour components, making them a potential HCC treatment.

AIM

To investigate the efficacy of SYPs for HCC treatment via simultaneous HIF-1α and PD-L1 inhibition and the mechanism involved.

METHODS

A subcutaneous xenograft tumour model was first established in BALB/c nude mice by the subcutaneous injection of 1 × 10⁷ SMMC-7721 cells. Male mice (male, 5 weeks old; n = 24) were then randomly divided into the following four groups (n = 6): Control (0.9% normal saline), SYP (200 mg/kg), SYP + cisplatin (DDP) (200 mg/kg + 5 mg/kg DDP weekly via intraperitoneal injection), and DDP (5 mg/kg cisplatin weekly via intraperitoneal injection). The dose of saline or SYPs for the indicated mouse groups was 0.2 mL/d via intragastric administration. The tumour volumes and body weights of the mice were measured every 2 d. The mice were euthanized by cervical dislocation after 14 d of continuous treatment, and the xenograft tissues were excised and weighed. Western blot assays were used to measure the protein expression of HIF-1α, PD­1, PD-L1, CD4+ T cells, and CD8+ T cells in HCC tumours from mice. Quantitative reverse transcription polymerase chain reaction was used for real-time quantitative detection of PD-1, PD-L1, and HIF-1α mRNA expression. An immunofluorescence assay was conducted to examine the expression of CD4+ T cells and CD8+ T cells.

RESULTS

Compared to mice in the control group, those in the SYP and SYP + DDP groups exhibited reduced tumour volumes and tumour weights. Moreover, the protein and mRNA expression levels of the oncogene HIF­1α and that of the negative immunomodulatory factors PD-1 and PD-L1 were decreased in both the SYP and SYP + DDP groups, with the decrease effects being more prominent in the SYP + DDP group than in the SYP group (HIF-1α protein: Control vs SYP, P = 0.0129; control vs SYP + DDP, P = 0.0004; control vs DDP, P = 0.0152, SYP + DDP vs DDP, P = 0.0448; HIF-1α mRNA: control vs SYP, P = 0.0009; control vs SYP + DDP, P < 0.0001; control vs DDP, P = 0.0003, SYP vs SYP + DDP, P = 0.0192. PD-1 protein: Control vs SYP, P = 0.0099; control vs SYP + DDP, P < 0.0001, SPY vs SYP + DDP, P = 0.0009; SYP + DDP vs DDP, P < 0.0001; PD-1 mRNA: control vs SYP, P = 0.0002; control vs SYP + DDP, P < 0.0001; control vs DDP, P = 0.0003, SPY vs SYP + DDP, P = 0.0003; SYP + DDP vs DDP, P = 0.0002. PD-L1 protein: control vs SYP, P < 0.0001; control vs SYP + DDP, P < 0.0001; control vs DDP, P < 0.0001, SPY vs SYP + DDP, P = 0.0040; SYP + DDP vs DDP, P = 0.0010; PD-L1 mRNA: Control vs SYP, P < 0.0001; control vs SYP + DDP, P < 0.0001; control vs DDP, P < 0.0001, SPY vs SYP + DDP, P < 0.0001; SYP + DDP vs DDP, P = 0.0014). Additionally, the quantitative and protein expression levels of CD4+ T cells and CD8+ T cells were simultaneously upregulated in the SYP + DDP group, whereas only the expression of CD4+ T cells was upregulated in the SYP group. (CD4+ T cell quantitative: Control vs SYP + DDP, P < 0.0001, SYP vs SYP + DDP, P = 0.0005; SYP + DDP vs DDP, P = 0.0002. CD4+ T cell protein: Control vs SYP, P = 0.0033; Control vs SYP + DDP, P < 0.0001; Control vs DDP, P = 0.0021, SYP vs SYP + DDP, P = 0.0004; SYP + DDP vs DDP, P = 0.0006. Quantitative CD8+ T cells: Control vs SYP + DDP, P = 0.0013; SYP vs SYP + DDP, P = 0.0347; SYP + DDP vs DDP, P = 0.0043. CD8+ T cell protein: Control vs SYP + DDP, P < 0.0001; SYP vs SYP + DDP, P < 0.0001; SYP + DDP vs DDP, P < 0.0001). Finally, expression of HIF-1α was positively correlated with that of PD-1/PD-L1 and negatively correlated with the expression of CD4+ T cells and CD8+ T cells.

CONCLUSION

SYPs inhibit immune escape and enhance chemosensitization in HCC via simultaneous inhibition of HIF-1α and PD-L1, thus inhibiting the growth of subcutaneous xenograft HCC tumours.

[Progress of researches on serine protease inhibitors for zoonotic cestode family Taeniidae]

Serine protease inhibitor, a protein superfamily that inhibits the serine protease activity, protects hosts from parasitic infections. This review describes the spatial structure and classification of serine protease inhibitor, mechanisms underlying the interplay between serine protease inhibitor and host immune responses and current advances in serine protease inhibitor of zoonotic cestode family Taeniidae, so as to provide insights into the diagnosis of zoonotic tapeworm infections, discovery of therapeutic targets and screening of vaccine candidates.