Thymosin α1 suppresses migration and invasion of PD-L1 high-expressing non-small-cell lung cancer cells via inhibition of STAT3-MMP2 signaling

Phenotypic drug discovery: a case for thymosin alpha-1

Phenotypic drug discovery (PDD) involves screening compounds for their effects on cells, tissues, or whole organisms without necessarily understanding the underlying molecular targets. PDD differs from target-based strategies as it does not require knowledge of a specific drug target or its role in the disease. This approach can lead to the discovery of drugs with unexpected therapeutic effects or applications and allows for the identification of drugs based on their functional effects, rather than through a predefined target-based approach. Ultimately, disease definitions are mostly symptom-based rather than mechanism-based, and the therapeutics should be likewise. In recent years, there has been a renewed interest in PDD due to its potential to address the complexity of human diseases, including the holistic picture of multiple metabolites engaging with multiple targets constituting the central hub of the metabolic host-microbe interactions. Although PDD presents challenges such as hit validation and target deconvolution, significant achievements have been reached in the era of big data. This article explores the experiences of researchers testing the effect of a thymic peptide hormone, thymosin alpha-1, in preclinical and clinical settings and discuss how its therapeutic utility in the precision medicine era can be accommodated within the PDD framework.

Repurposing drugs for solid tumor treatment: focus on immune checkpoint inhibitors

Cancer remains a significant global health challenge with limited treatment options beyond systemic therapies, such as chemotherapy, radiotherapy, and molecular targeted therapy. Immunotherapy has emerged as a promising therapeutic modality but the efficacy has plateaued, which therefore provides limited benefits to patients with cancer. Identification of more effective approaches to improve patient outcomes and extend survival are urgently needed. Drug repurposing has emerged as an attractive strategy for drug development and has recently garnered considerable interest. This review comprehensively analyses the efficacy of various repurposed drugs, such as transforming growth factor-beta (TGF-β) inhibitors, metformin, receptor activator of nuclear factor-κB ligand (RANKL) inhibitors, granulocyte macrophage colony-stimulating factor (GM-CSF), thymosin α1 (Tα1), aspirin, and bisphosphonate, in tumorigenesis with a specific focus on their impact on tumor immunology and immunotherapy. Additionally, we present a concise overview of the current preclinical and clinical studies investigating the potential therapeutic synergies achieved by combining these agents with immune checkpoint inhibitors.

Wilms' tumour gene 1 (WT1) enhances non-small cell lung cancer malignancy and is inhibited by microRNA-498-5p

BACKGROUND

Wilms' tumour gene 1 (WT1) is clearly recognized as a tumour promoter in diversiform of human malignancies. Nevertheless, knowledge of its expression, functions and potential molecular mechanisms in non-small cell lung cancer (NSCLC) remains elusive.

METHODS

Differential expression of WT1 mRNA and protein between NSCLC and normal tissues were assessed by analyzing RNA-seq data from Oncomine and protein data from Human Protein Atlas, respectively. Subsequently, prognosis significance and immune cell infiltration were analyzed by Kaplan-Meier plotter and CIBERSORT. 60 pairs of local NSCLC tissues were involved to validate WT1 expression by quantitative PCR (qPCR) and Western blot. Moreover, Cell Counting Kit-8 (CCK-8), colony formation, transwell, dual luciferase reporter assays and in vivo xenograft tumour growth experiments were conducted to explore the function and mechanism of WT1 in NSCLC.

RESULTS

Our solid data indicated that WT1 was increased in NSCLC tissues and cell lines in comparison with their matched controls. In particular, its upregulation correlated with worse prognosis and immune infiltration of the patients. Functional assays demonstrated that knockdown of WT1 inhibited NSCLC malignancy, including inhibiting cell proliferation, survival and invasion. Further exploration discovered that microRNA-498-5p (miR-498-5p) was the upstream suppressor of WT1 by directly targeting the 3' untranslated region (UTR) of WT1 mRNA. Moreover, expression of miR-498-5p was notably decreased and inversely correlated with WT1 in NSCLC tissues. Finally, we proved that miR-498-5p was a potent tumour suppressor in NSCLC by suppressing cell proliferation, survival and invasion, while WT1 restoration could in turn disrupt this suppression both in vitro and in vivo.

CONCLUSION

The abnormal increase in WT1 contributes to the malignant properties of NSCLC cells, and miR-498-5p is a natural inhibitor of WT1. Our findings might facilitate the development of novel therapeutic strategies against NSCLC in the future.

Mechanism and clinical application of thymosin in the treatment of lung cancer

Cancer is one of the leading causes of death worldwide. The burden of cancer on public health is becoming more widely acknowledged. Lung cancer has one of the highest incidence and mortality rates of all cancers. The prevalence of early screening, the emergence of targeted therapy, and the development of immunotherapy have all significantly improved the overall prognosis of lung cancer patients. The current state of affairs, however, is not encouraging, and there are issues like poor treatment outcomes for some patients and extremely poor prognoses for those with advanced lung cancer. Because of their potent immunomodulatory capabilities, thymosin drugs are frequently used in the treatment of tumors. The effectiveness of thymosin drugs in the treatment of lung cancer has been demonstrated in numerous studies, which amply demonstrates the potential and future of thymosin drugs for the treatment of lung cancer. The clinical research on thymosin peptide drugs in lung cancer and the basic research on the mechanism of thymosin drugs in anti-lung cancer are both systematically summarized and analyzed in this paper, along with future research directions.

Thymosin β4 Alleviates Autoimmune Dacryoadenitis via Suppressing Th17 Cell Response

Purpose

We investigated the therapeutic effect of recombinant thymosin β4 (rTβ4) on rabbit autoimmune dacryoadenitis, an animal model of SS dry eye, and explore its mechanisms.

Methods

Rabbits were treated topically with rTβ4 or PBS solution after disease onset for 28 days, and clinical scores were determined by assessing tear secretion, break-up time, fluorescein, hematoxylin and eosin staining, and periodic acid-Schiff. The expression of inflammatory mediators in the lacrimal glands were measured by real-time PCR. The expression of T helper 17 (Th17) cell-related transcription factors and cytokines were detected by real-time PCR and Western blotting. The molecular mechanism underlying the effects of rTβ4 on Th17 cell responses was investigated by Western blotting.

Results

Topical administration of rTβ4 after disease onset efficiently ameliorated the ocular surface inflammation and relieved the clinical symptoms. Further analysis revealed that rTβ4 treatment significantly inhibited the expression of Th17-related genes (RORC, IL-17A, IL-17F, IL-1R1, IL-23R, and granulocyte-macrophage colony-stimulating factor) and IL-17 protein in lacrimal glands, and meanwhile decreased the inflammatory mediators expression. Mechanistically, we demonstrated that rTβ4 repressed the phosphorylation of signal transducer and activator of transcription 3 (STAT3) both in vivo and in vitro. Activation of the STAT3 signal pathway by Colivelin partly reversed the suppressive effects of rTβ4 on IL-17 expression in vitro.

Conclusions

rTβ4 could alleviate ongoing autoimmune dacryoadenitis in rabbits, probably by suppressing Th17 response via partly affecting the STAT3 pathway. These data may provide a new insight into the therapeutic effect and mechanism of rTβ4 in dry eye associated with Sjögren's syndrome.

Saikosaponin A alleviates glycolysis of breast cancer cells through repression of Akt/STAT3 pathway

Saikosaponin A (SSA) has been revealed to have anti-breast cancer (BC) effect. However, the association between SSA and BC glycolysis is obscure. We want to probe the function and mechanism of SSA on BC glycolysis. Kaplan-Meier plotter revealed the relationship between STAT3 and the survival curve of BC. The protein kinase B (Akt)/signal transducer and activator of transcription 3 (STAT3) pathway and the viability in cells treated with or without 0, 5, 10, and 15 μM SSA were assessed by Western blot and cell counting kit-8. The biological behaviors, lactate, and ATP contents, glucose uptake, and Akt/STAT3 pathway-related markers in BC cells treated with colivelin or SSA were evaluated using cell function experiments, kit, and Western blot. Then, the impacts of colivelin and SSA on BC cells were tested again. The overexpressions of p-STAT3 and p-Akt in BC cells were weakened by 5, 10, and 15 μM SSA. Colivelin boosted the BC cell viability and proliferation and impeded apoptosis, while SSA did the opposite. Meanwhile, colivelin intensified lactate and ATP contents, glucose uptake, and Akt/STAT3 pathway-related markers level in BC cells, while SSA was the opposite. The modulation of SSA on the biological behavior, lactate and ATP productions, glucose uptake, and Akt/STAT3 pathway was rescued by colivelin. Our research unveiled new insights into SSA as a valuable candidate therapeutic agent for weakening glycolysis, and protruded the Akt/STAT3 pathway as a latent molecular target for SSA and glycolysis modulation.

Synergistic anti-cancer and attenuation effects of thymosin on chemotherapeutic drug vinorelbine in tumor-bearing zebrafish

Vinorelbine, the standard chemotherapy drug on advanced lung cancer, causes adverse events such as immunosuppression and bone marrow suppression. Thus, it is necessary to find drugs that could improve immune function and synergistically enhance the anti-tumor effect of vinorelbine. Thymosin is reported to inhibit tumor growth as an immunomodulator. Herein, to study the synergistic anti-cancer and attenuation effects of thymosin on vinorelbine, human lung cancer A549 cells that were labeled with CM-DiI were transplanted into zebrafish to establish the lung cancer xenotransplanted model. After treatment of vinorelbine and different concentrations of thymosin, the fluorescence intensity of CM-DiI-labeled A549 cells and the number of apoptotic muscle cells in the tumor-bearing zebrafish were detected. Besides, effects of thymosin on vinorelbine-reduced macrophages and T cells were identified in the transgenic zebrafish (Tg:zlyz-EGFP and Tg:rag2-DsRed). Then, the qRT-PCR was used to determine the alterations of the immune-related factors at the transcription level. Thymosin showed a marked synergistic anti-cancer effect with vinorelbine for the xenograft human lung cancer A549 cells, and the synergistic effect enhanced in a dose-dependent manner. Moreover, thymosin alleviated vinorelbine-induced muscle cell apoptosis, macrophage reduction, and T cell suppression. Compared with the vinorelbine group, co-administration with thymosin raised the mRNA levels of TNF-α, TNF-β, INF-γ, and GM-CSF. Thus, thymosin possesses synergistic anti-cancer effect on vinorelbine, and has protective effect on vinorelbine-induced immunosuppression. Thymosin, as an adjuvant immunomodulatory therapy, has great potential in enhancing the clinical application of vinorelbine.

Thymosin alpha 1 - Reimagine its broader applications in the immuno-oncology era

Thymosin alpha 1 (Tα1) is a highly conserved 28 amino-acid peptide naturally occurring in the thymus and plays critical roles in T cell maturity and differentiation. Its synthetic form, thymalfasin, has been approved by various regulatory agencies in the treatment of hepatitis B viral infection and as an enhancer of vaccine response in immune-compromised populations. In China, it has also widely utilized in patients with cancer and severe infections, as well as the emergency use during (Severe Acute Respiratory Syndrome)SARS and COVID-19 pandemic as an immune-regulator. Recent studies showed that Tα1 could significantly improve overall survival (OS) in patients with surgically resectable non-small cell lung cancer (NSCLC) and liver cancers in the adjuvant setting. For patients with locally advanced, unresectable NSCLC, Tα1 could significantly reduce chemoradiation-induced lymphopenia, pneumonia, and trending improvement of OS. Preclinical evidence are emerging to demonstrate that Tα1 may augment efficacy of cancer chemotherapy by reversing efferocytosis-induced M2 polarization of macrophages via activation of a TLR7/SHIP1 axis and enhancing anti-tumor immunity by turning "cold-tumors" to "hot-tumors"; a protective role in reducing colitis caused by immune check-point inhibitors (ICIs). Potential enhancement of ICIs' clinical efficacies has also been indicated. ICIs have transformed ways treating patients with cancer but limitations such as relatively low response rates and certain safety issues remains. Given the roles of Tα1 in regulating cellular immunities and exceptional safety profiles demonstrated in decades clinical uses, we believe that it is plausible to explore implications of Tα1 the immune-oncology setting by combining with ICI-based therapeutic strategies. Background Activities of Tα1. Tα1 is a biological response modifier which activates various cells in the immune system [1-3]. Tα1 is therefore expected to have clinical benefits in disorders where immune responses are impaired or ineffective. These disorders include acute and chronic infections, cancers, and vaccine non-responsiveness. In severe sepsis, for example, sepsis-induced immunosuppression is increasingly recognized as the overriding immune dysfunction in these vulnerable patients [4] and there is now agreement that many patients with severe sepsis survive the first critical hours of the syndrome but eventually die later due to patients' immunosuppression which make the system difficulty to fight the primary bacterial infection, decreased resistance to secondary nosocomial infections, and reactivation of viral infections [5]. Tα1 has been shown to restore immune functions and help to reduce mortality in patients with severe sepsis.

Thymosin α-1 in cancer therapy: Immunoregulation and potential applications

Thymosin α-1 (Tα-1) is an immunomodulating polypeptide of 28 amino acids, which was the first peptide isolated from thymic tissue and has been widely used for the treatment of viral infections, immunodeficiencies, and especially malignancies. Tα-1 stimulates both innate and adaptive immune responses, and its regulation of innate immune cells and adaptive immune cells varies under different disease conditions. Pleiotropic regulation of immune cells by Tα-1 depends on activation of Toll-like receptors and its downstream signaling pathways in various immune microenvironments. For treatment of malignancies, the combination of Tα-1 and chemotherapy has a strong synergistic effect by enhancing the anti-tumor immune response. On the basis of the pleiotropic effect of Tα-1 on immune cells and the promising results of preclinical studies, Tα-1 may be a favorable immunomodulator to enhance the curative effect and decrease immune-related adverse events of immune checkpoint inhibitors to develop novel cancer therapies.

Thymosin alpha1 use in adult COVID-19 patients: A systematic review and meta-analysis on clinical outcomes

OBJECTIVE

Thymosin alpha1 (Ta1) is widely used to treat patients with coronavirus disease 2019 (COVID-19), however, its effect remains unclear. This systematic review and meta-analysis aimed to evaluate the effect of Ta1 as a COVID-19 therapy.

METHODS

PubMed, EMBASE, the Cochrane library, Web of Science, and the reference lists of relevant articles were searched to identify eligible studies. Assessment of heterogeneity was done using the I-squared (I²) test and random/fixed effect analysis was done to determine the risk ratio (RR). We polled the data related to mortality mainly by using Review Manager 5.4. Predefined subgroup analyses and sensitivity analyses were also performed.

RESULTS

A total of 9 studies were included, on a total of 5352 (Ta1 = 1152, control = 4200) patient outcomes. Meta-analysis results indicated that Ta1 therapy had no statistically significant effect on mortality [RR 1.03 (0.60, 1.75), p = 0.92, I² = 90 %]. Subgroup analyses demonstrated that the beneficial effect in mortality was associated with mean age＞60 years in the Tα1 group [RR 0.68 (0.58, 0.78), p < 0.0000.1, I² = 0 %], the proportion of female ≤ 40 % in the Tα1 group [RR 0.67 (0.58, 0.77), p < 0.0000.1, I² = 0 %], and severe/critical COVID-19 patients [RR 0.66 (0.57, 0.76), p < 0.0000.1, I² = 0 %]. Sensitivity analysis further demonstrated the results to be robust.

CONCLUSIONS

The results of this meta-analysis do not support the use of Ta1 in hospitalized adult COVID-19 patients.

Effect of Thymosin on Inflammatory Factor Levels, Immune Function, and Quality of Life in Lung Cancer Patients Undergoing Radical Thoracoscopic Surgery

Purpose

To explore the effect of thymosin on inflammatory factor levels, immune function, and quality of life in patients undergoing radical thoracoscopic lung cancer surgery.

Methods

One hundred and twenty patients admitted to the Surgical Oncology Department of the First Hospital of Jiaxing from January 2018 to January 2019 were randomized into the study group and the control group using the random number table method, with 60 cases in each group. The control group was treated with radical thoracoscopic lung cancer surgery, and the study group was treated with radical thoracoscopic lung cancer surgery combined with thymosin. The clinical efficiency, inflammatory factors, immune function, and quality of life between the two groups of patients were compared.

Results

There was no significant difference between the two groups in terms of pathological stage, tissue type, maximum tumor diameter, and perioperative indicators such as operative time, intraoperative bleeding, pleural drainage, hospital stay, and the number of intraoperative lymph nodes removed. The levels of CD4 (+%), CD8 (+%), CD4+/CD8+, and natural killer cell (NK) (%) were significantly decreased in both groups after treatment, with significantly higher results in the study group than in the control group. The study group had significantly lower serum interleukin-6 (IL-6) levels and higher interleukin-10 (IL-10) levels than the control group. After treatment, patients in the study group had better postoperative physiological status and overall score than the control group. There was no significant difference in postoperative survival and adverse reactions between the two groups.

Conclusion

The use of thymosin treatment in lung cancer patients undergoing radical thoracoscopic surgery significantly improves immune function, mitigates inflammatory response, and enhances the quality of life, which is worthy of clinical application.

LINC00858 promotes colon cancer progression through activation of STAT3/5 signaling by recruiting transcription factor RAD21 to upregulate PCNP

The purpose of our investigation is to explore the putative molecular mechanisms underpinning LINC00858 involvement in colon cancer. The expression of LINC00858 in TCGA data was identified using the GEPIA website. Colon cancer cancerous tissues were clinically collected. The expression of LINC00858, RAD21, and PCNP in colon tissues or cells was determined using RT-qPCR. The interactions among LINC00858, RAD21, and PCNP promoter region were determined by means of RNA pull down, RIP, and ChIP assays. Cell proliferative, apoptotic, invasive, and migrated capabilities were evaluated. Western blot was conducted to determine RAD21, PCNP, phosphorylated (p)-STAT3, STAT3, p-STAT5 and STAT5 and apoptosis related proteins. A nude mouse model of colon cancer was constructed and tumorigenesis of colon cancer cells was observed. LINC00858 was upregulated in cancerous tissues and cells. LINC00858 recruited the transcription factor RAD21. Overexpression of LINC00858 promoted the binding of RAD21 and PCNP promoter region, which increased the expression of PCNP. Silencing of RAD21 or PCNP reversed the promoting effect of LINC00858 on the disease initiation and development. PCNP silencing inhibited proliferative ability and promoted apoptotic ability of cancerous cells via STAT3/5 inhibition, which was reversed by colivelin-activated STAT3. In vivo experiments further verified that LINC00858 enhanced the tumorigenicity of colon cancer cells in vivo by regulating the RAD21/PCNP/STAT3/5 axis. It indicated the promoting role of LINC00858 in colon cancer progression though activating PCNP-mediated STAT3/5 pathway by recruiting RAD21.

Anti-EpCAM functionalized graphene oxide vector for tumor targeted siRNA delivery and cancer therapy

Graphene oxide (GO) has emerged as a potential drug delivery vector. For siRNA delivery, GO should be modified to endow it with gene delivery ability and targeting effect. However, the cationic materials used previously usually had greater toxicity. In this study, GO was modified with a non-toxicity cationic material (chitosan) and a tumor specific monoclonal antibody (anti-EpCAM) for the delivery of survivin-siRNA (GCE/siRNA). And the vector (GCE) prepared was proved with excellent biosafety and tumor targeting effect. The GCE exhibited superior performance in loading siRNA, maintained stability in different solutions and showed excellent protection effect for survivin-siRNA in vitro. The gene silencing results in vitro showed that the mRNA level and protein level were down-regulated by 48.24% ± 2.50% and 44.12% ± 3.03%, respectively, which was equal with positive control (P > 0.05). It was also demonstrated that GCE/siRNA had a strong antitumor effect in vitro, which was attributed to the efficient antiproliferation, and migration and invasion inhibition effect of GCE/siRNA. The results in vivo indicated that GCE could accumulate siRNA in tumor tissues. The tumor inhibition rate of GCE/siRNA 54.74% ± 5.51% was significantly higher than control 4.87% ± 8.49%. Moreover, GCE/siRNA showed no toxicity for blood and main organs, suggesting that it is a biosafety carrier for gene delivery. Taken together, this study provides a novel design strategy for gene delivery system and siRNA formulation.

Elevated mRNA Level of Y-Box Binding Protein 1 Indicates Unfavorable Prognosis Correlated with Macrophage Infiltration and T Cell Exhaustion in Luminal Breast Cancer

Purpose

The Y-box binding protein 1 (YBX1) gene encodes the multifunctional protein YB1 that is associated with the dysregulation of numerous cancer-related genes. However, the prognostic value of YBX1 and its correlation with immune cell infiltration in breast cancer (BRCA) remain unclear.

Methods

YBX1 expression data in various malignancies were obtained from Oncomine, Tumor Immune Estimation Resource (TIMER), Cancer Cell Line Encyclopedia, UALCAN and cBio Cancer Genomics Portal databases. Survival data were analyzed with Kaplan–Meier plotter. Immune cell infiltration and its association with YBX1 expression level were assessed with TIMER and LinkedOmics. YB1 expression was evaluated by immunohistochemistry and Western blotting, and changes in cancer cell viability and T cell activity following YBX1 knockdown were assessed with an immunocyte–tumor cell co-culture assay.

Results

YBX1 was downregulated in the BRCA cohort, which was closely associated with worse prognosis in the luminal A subtype (overall survival [OS]: hazard ratio [HR] 1.93, 95% confidence interval [CI] 1.22–3.05, P = 0.0042; recurrence-free survival [RFS]: HR 1.85, 95% CI 1.51–2.28, P = 3.1e-9) and luminal B subtype (OS: HR 1.08, 95% CI 0.68–1.70, P = 0.75; RFS: HR 1.29, 95% CI 1.02–1.62, P = 0.03). YBX1 expression was positively correlated with the M2 macrophage infiltration and expression of T cell exhaustion markers such as indoleamine 2,3-dioxygenase 1 (IDO1) (rs = 0.388, P = 4.93e-37) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) (rs = 0.321, P = 2.54e-25) in luminal BRCA. Kaplan–Meier analysis revealed a correlation between YBX1 expression, M2 infiltration and survival outcome. Co-culture with macrophages or T cells enhanced the decrease in luminal BRCA cell viability induced by YBX1 knockdown.

Conclusion

High YBX1 mRNA levels predict a poor prognosis in luminal BRCA, which is correlated with M2 macrophage infiltration and T cell exhaustion in the tumor microenvironment. Combining classic therapeutics with immune checkpoint inhibitors and M1 polarization agents may be an effective treatment strategy for luminal BRCA with YBX1 overexpression.

Inhibition of programmed death ligand 1 (PD-L1) expression in breast cancer cells by sesamin

Programmed death ligand 1 (PD-L1) is overexpressed in some metastatic breast cancer subtypes, specifically triple-negative breast cancer (TNBC). This feature can assist in the eradication of anti-tumor immunity, thereby enhancing the survival of the tumor. This study aims to explore how sesamin affects PD-L1 expression in breast cancer cells and its related molecular mechanisms. We found high levels of expression of PD-L1 in both mRNA and protein levels in the TNBC cell line, MDA-MB231, but not in the luminal type-breast cancer cell line, MCF-7. We then demonstrated the tumor suppressive effect of sesamin, which induced the inhibition of cell proliferation in MDA-MB231 cells. Additionally, sesamin triggered PD-L1 downregulation (both mRNA and protein) through the inhibition of AKT, NF-κB and JAK/Stat signaling in MDA-MB231 cells. Moreover, the migration ability of MDA-MB231 cells was effectively diminished by sesamin via inhibition of the activation of MMP-9 and MMP-2. In summary, this study demonstrated that sesamin suppresses MDA-MB231 breast cancer cells' proliferation and migration; and decreases the expression of PD-L1 via the downregulation of AKT, NF-κB, and JAK/Stat signaling. Therefore, sesamin may be an effective alternative and novel therapeutic option for immunotherapy in breast cancer cells with high PD-L1 expression.

Detection of PD-L1 Expression and Its Clinical Significance in Circulating Tumor Cells from Patients with Non-Small-Cell Lung Cancer

Background

The expression of programmed cell death ligand 1(PD-L1) is related to the efficacy of immune checkpoint inhibitors on patients with non-small cell lung cancer (NSCLC), but tumor tissue (TT) samples are difficult to obtain, and initial TT samples are difficult to reflect the spatial-temporal heterogeneity. Therefore, we explored the feasibility of separating circulating tumor cells (CTCs) and detecting PD-L1 expression on CTCs.

Patients and Methods

Peripheral blood specimens were sampled from 66 NSCLC patients, and CTCs were separated by membrane filtration based on size. For 59 patients with paired TT specimens, the expression of PD-L1 in their CTCs and TTs was determined using the immunohistochemistry and immunocytochemistry based on 28–8 antibody, respectively. The PD-L1 expression in TTs was set as a gold standard for calculation of sensitivity, specificity, consistency, positive predictive value (PPV), and negative predictive value (NPV), and the Cohen kappa coefficient for CTCs and paired TTs was calculated. In addition, the T-test, Chi-square test, and Mann–Whitney U-test were adopted to analyze the correlation of clinical pathological features and prognosis with PD-L1 expression.

Results

Sensitivity, specificity, concordance, PPV and NPV of detecting PD-L1 in CTCs of the 41 initial treated patients were 88.89%, 73.91%, 80%, 72.73% and 89.47%, respectively, and the Cohen kappa coefficient of CTC and paired TTs was 0.613. The univariate analysis of survival showed that the progression-free survival time of initial treated patients with positive PD-L1 expression was shorter than that of those with negative PD-L1 expression in CTCs or TTs (P>0.05), and the positive PD-L1 expression in CTCs or TTs had nothing to do with age, sex, smoking status, histological type, and stage (P > 0.05).

Conclusion

The study confirms the feasibility of CTC PD-L1 detection in peripheral blood and lays a foundation for exploring real-time and individualized immunotherapy molecular biomarkers.

Inhibitory Effect of Hesperidin on the Expression of Programmed Death Ligand (PD-L1) in Breast Cancer

Programmed death ligand 1 (PD-L1) is overexpressed in the most aggressive breast cancer subtype, triple-negative breast cancer (TNBC), assisting the eradication of antitumor immunity, and thereby enhancing the survival of the tumor. This study explored how hesperidin affects PD-L1 expression, and thereby cancer progression in breast cancer cells. We found that MDA-MB231, the triple-negative breast adenocarcinoma cancer cell line, (high aggressiveness) has higher expression, in both mRNA and protein, of PD-L1 than that of the other breast cancer cell line, MCF-7 (low aggressiveness). Hesperidin inhibited cell proliferation in MDA-MB231 cells. Additionally, high expression of PD-L1 (both mRNA and protein) in aggressive cancer cells was strongly inhibited by hesperidin through inhibition of Akt and NF-κB signaling. Moreover, hesperidin treatment, by inhibiting activation of matrix metalloproteinases such as MMP-9 and MMP-2, suppressed the metastatic phenotype and cell migration in the PD-L1 high-expressing MDA-MB231 cells. In summary, hesperidin inhibits breast cancer cell growth through the inhibition of the expression of PD-L1 via downregulation of Akt and NF-κB signaling in TNBC. Moreover, hesperidin significantly suppresses cell migration of MDA-MB231 cells. Our findings reveal fresh insights into the anticancer effects of hesperidin which might have potential clinical implications.

Dynasore suppresses cell proliferation, migration, and invasion and enhances the antitumor capacity of cisplatin via STAT3 pathway in osteosarcoma

Osteosarcoma (OS) is the most common malignant bone tumor. The prognosis of metastatic and recurrent OS patients still remains unsatisfactory. Cisplatin reveals undeniable anti-tumor effect while induces severe side effects that threatening patients’ health. Dynasore, a cell-permeable small molecule that inhibits dynamin activity, has been widely studied in endocytosis and phagocytosis. However, the anti-tumor effect of dynasore on OS has not yet been ascertained. In the present study, we suggested that dynasore inhibited cell proliferation, migration, invasion, and induced G0/G1 arrest of OS cells. Besides, dynasore repressed tumorigenesis of OS in xenograft mouse model. In addition, we demonstrated that dynasore improved the anti-tumor effect of cisplatin in vitro and in vivo without inducing nephrotoxicity and hepatotoxicity. Mechanistically, dynasore repressed the expression of CCND1, CDK4, p-Rb, and MMP-2. Furthermore, we found that dynasore exerts anti-tumor effects in OS partially via inhibiting STAT3 signaling pathway but not ERK-MAPK, PI3K-Akt or SAPK/JNK pathways. P38 MAPK pathway served as a negative regulatory mechanism in dynasore induced anti-OS effects. Taken together, our study indicated that dynasore does suppress cell proliferation, migration, and invasion via STAT3 signaling pathway, and enhances the antitumor capacity of cisplatin in OS. Our results suggest that dynasore is a novel candidate drug to inhibit the tumor growth of OS and enhance the anti-tumor effects of cisplatin.

A Reappraisal of Thymosin Alpha1 in Cancer Therapy

Thymosin alpha1 (Tα1), an endogenous peptide first isolated from the thymic tissue in the mid-sixties, has gained considerable attention for its immunostimulatory activity that led to its application to diverse pathological conditions, including cancer. Studies in animal models and human patients have shown promising results in different types of malignancies, especially when Tα1 was used in combination with other chemo- and immune therapies. For this reason, the advancements in our knowledge on the adjuvant role of Tα1 have moved in parallel with the development of novel cancer therapies in a way that Tα1 was integrated to changing paradigms and protocols, and tested for increased efficacy and safety. Cancer immunotherapy has recently experienced a tremendous boost following the development and clinical application of immune checkpoint inhibitors. By unleashing the full potential of the adaptive immune response, checkpoint inhibitors were expected to be very effective against tumors, but it soon became clear that a widespread and successful application was not straightforward and shortcomings in efficacy and safety clearly emerged. This scenario led to the development of novel concepts in immunotherapy and the design of combination protocols to overcome these limitations, thus opening up novel opportunities for Tα1 application. Herein, we summarize in a historical perspective the use of Tα1 in cancer, with particular reference to melanoma, hepatocellular carcinoma and lung cancer. We will discuss the current limitations of checkpoint inhibitors in clinical practice and the mechanisms at the basis of a potential application of Tα1 in combination protocols.

Down-regulated circPAPPA suppresses the proliferation and invasion of trophoblast cells via the miR-384/STAT3 pathway

Preeclampsia (PE) is the main cause of maternal death in primipara, and commonly results in severe maternal and neonatal complications such as multiple organ dysfunction syndrome. However, the exact pathogenesis of this disease remains unclear. Circular RNAs (circRNAs) are noncoding RNAs that have been shown to be extensively involved in numerous physiological processes, but there is limited knowledge of their functions and mechanisms in PE. In the present study, we found the expression of a circRNA, hsa_circ_0088227 (circRNA of pregnancy-associated plasma protein A, circPAPPA), was down-regulated in both placenta and plasma samples from subjects with PE. Knockdown of circPAPPA led to decreased proliferation and invasion in HTR8-S/Vneo trophoblast cells. miR-384 was identified as a direct target of circPAPPA, and the gene encoding signal transducer and activator of transcription 3 (STAT3) was targeted by miR-384. We found that miR-384 was unregulated in PE, and overexpression of miR-384 could inhibit cell proliferation and invasion. In addition, we showed that the expression of STAT3 was decreased with knockdown of circPAPPA or the overexpression of miR-384 in trophoblast cells, but this decrease was partially reversed when co-transfection was performed with mimics of miR-384 inhibitor and si-circPAPPA. Together, these results suggest that down-regulation of circPAPPA facilitates the onset and development of PE by suppressing trophoblast cells, with involvement of the miR-384/STAT3 signaling pathway. Our study significantly increases the understanding of the occurrence and development of PE, and also provides a molecular target for the treatment of this disorder.

[Role of STAT3 in Resistance of Non-small Cell Lung Cancer]

近年来，肿瘤炎症微环境对非小细胞肺癌（non-small cell lung cancer, NSCLC）耐药影响的机制研究刚刚起步，信号传导及转录激活因子3（signal transducers and activators of transcription 3, STAT3）作为连接炎症和肿瘤的关键信号通路分子，其活化可引起肿瘤细胞中诸多基因沉默、表达异常及基因的不稳定等，诱导化疗、靶向药物治疗耐药，有望成为潜在的逆转耐药的新靶点。本综述阐述了STAT3在NSCLC获得性耐药中的研究进展，以探讨其作为逆转耐药新靶点的可能性，为NSCLC获得性耐药的临床治疗新策略提供理论依据。