Endostatin enhances antitumor effect of tumor antigen-pulsed dendritic cell therapy in mouse xenograft model of lung carcinoma

A real-world study of recombinant human endostatin combined with PD-1/PD-L1 blockade and chemotherapy for patients with advanced non-small cell lung cancer negative for actionable molecular biomarkers

The ongoing ENPOWER study exploring the efficacy and safety of the recombinant human endostatin (endostar) combined with programmed cell death 1 antibody sintilimab and chemotherapy showed encouraging efficacy and safety in advanced non-squamous non-small cell lung cancer. To evaluate the real-world efficacy and safety of endostar combined with immune checkpoint inhibitor and chemotherapy (EIC) for advanced non-squamous non-small cell lung cancer patients negative for actionable molecular biomarkers (NSCLCnm), patients with advanced NSCLCnm hospitalized to Zhejiang Provincial People's Hospital from January 2020 to December 2022 were screened for eligibility. The included patients were analyzed for the objective response rate (ORR) and disease control rate (DCR). The pre- and posttreatment expression levels of serum tumor associated biomarkers, chemokines and subpopulations of immune cells in peripheral blood were compared. For the 31 patients with advanced NSCLCnm treated with EIC, the median follow-up and treatment cycles were 18.0 months and 4, respectively. The ORR and DCR were 38.7% and 90.3%, respectively. For those who received EIC as first-line treatment, the ORR and DCR were 63.2% and 94.7%, respectively. EIC significantly decreased expression levels of carcinoma antigen 125, carcinoma embryonic antigen and cytokeratin 19 (P<0.05) in patients who were partial remission or stable disease. Among the 31 patients, 27 (87.1%) experienced at least 1 treatment-related adverse events, and 13 (41.9%) had the treatment-related adverse events of grade 3 or higher. No antiangiogenesis-related adverse events were observed. The current study showed that EIC was potentially effective for patients with NSCLCnm, especially when used as first-line therapy, and well tolerated.

Synergy of Polydopamine Nanovaccine and Endostar Alginate Hydrogel for Improving Antitumor Immune Responses Against Colon Tumor

BACKGROUND

Tumor immunotherapy, a novel type of therapeutic treatment, has a wide range of applications with potentially prolonged benefits. However, current immunotherapy has a low overall response rate in treating a variety of tumors. Combination of immunotherapy with other therapies can improve the therapeutic response rates. The purpose of this work was to explore the potential of anti-angiogenic treatment in combination with tumor cell lysate loaded polydopamine nanoparticle vaccine as a therapeutic strategy for colon tumor.

METHODS

We grafted tumor cell lysate onto polydopamine nanoparticles as nano-vaccine (TCLN) and fabricated alginate hydrogel loaded with Endostar (EH), then detected characteristics of EH and TCLN. We also estimated the cytotoxicity of EH/TCLN in vitro. In the tumor-bearing mouse model, we evaluated the antitumor effect of EH/TCLN treatment, and developed the animal survival study. After performing the EH/TCLN treatment, we also analyzed T cells and DCs using flow cytometry, and determined T cell responses and tumor microenvironmental cytokines. At last, we assessed the effect of the EH/TCLN treatment on anti-angiogenesis further.

RESULTS

When applied in combination with TCLN in MC-38 tumor-bearing mice, EH/TCLN significantly suppressed tumor growth with more than half of the mice showing tumor regression. In addition, EH/TCLN treatment resulted in noticeable changes in the tumor microenvironment. As compared with the control group, EH/TCLN treatment led to significantly reduced tumor angiogenesis and expression of tumor microenvironment-related cytokines (TMCs), increased proportion of CD8⁺ T cells in the spleen, lymph node and tumor, elevated activity of cytotoxic T lymphocytes (CTLs) and tumor cell apoptosis.

CONCLUSION

The present study demonstrated that the EH/TCLN treatment effectively created a favorable immune microenvironment for the induction of antitumor immunity and improved antitumor immune responses.

A novel form of docetaxel polymeric micelles demonstrates anti-tumor and ascites-inhibitory activities in animal models as monotherapy or in combination with anti-angiogenic agents

Malignant ascites (MA) is caused by intraperitoneal spread of solid tumor cells and results in a poor quality of life. Chemotherapy is a common first-line treatment for patients with MA. Taxotere ^® (DTX) is widely used in solid tumor therapies. However, the low water solubility and side effects caused by additives in the formulation restrict the clinical application of docetaxel. HT001 is a clinical stage docetaxel micelle developed to overcome the solubility issue with improved safety profiles. To support clinical development and expand clinical application of HT001, this study used in vitro and in vivo approaches to investigate the anti-tumor effects of HT001 when applied as monotherapy or in combination with anti-angiogenic agents. HT001 demonstrated comparable anti-proliferative activities as docetaxel in a broad range of cancer cell lines in vitro. Furthermore, HT001 suppressed tumor growth in a dose-dependent manner in A549, MCF-7, and SKOV-3 xenograft tumor mouse models in vivo. In a hepatocellular carcinoma H22 malignant ascites-bearing mouse model, HT001 presented a dose-dependent inhibition of ascites production, prolonged animal survival, and reduced VEGF levels. When dosed at 20 mg/kg, the HT001-treated group exhibited curative results, with no ascites formation in 80% of mice at the end of the study while all the mice in the vehicle control group succumbed. Similar results were obtained in HT001 treatment of mice bearing malignant ascites produced by human ovarian cancer ES-2 cells. Notably, the combination of HT001 with Endostar not only significantly reduced ascites production but also prolonged survival of H22 ascites-bearing mice. HT001 showed similar PK and tissue distribution profiles as DTX in non-rodent hosts. Collectively, these results demonstrate potent anti-tumor activity of HT001 in multiple solid tumor models or malignant ascites models, and reveal synergistic effects with anti-angiogenic agents, supporting the clinical development and clinical expansion plans for HT001.

Acquired resistance for immune checkpoint inhibitors in cancer immunotherapy: challenges and prospects

Drug resistance has become an obstacle to the further development of immunotherapy in clinical applications and experimental studies. In the current review, the acquired resistance to immunotherapy was examined. The mechanisms of acquired resistance were based on three aspects as follows: The change of the tumor functions, the upregulated expression of inhibitory immune checkpoint proteins, and the effects of the tumor microenvironment. The combined use of immunotherapy and other therapies is performed to delay acquired resistance. A comprehensive understanding of acquired drug resistance may provide ideas for solving this dilemma.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial–mesenchymal transition, and migration of cancer cells).

Endostatin inhibits the proliferation and migration of B16 cells by inducing macrophage polarity to M1‑type

Malignant melanoma is a common skin tumor that easily metastasizes and has a poor prognosis. Endostatin is an endogenous vascular endothelial inhibitor that mainly suppresses tumor growth by inhibiting the proliferation of vascular endothelial cells and by reducing the formation of tumor microvessels, however the immunological function of endostatin remains unclear. Previously, we have found that an over‑expression endostatin (pEndostatin) plasmid induced RAW264.7 cells' polarity to M1‑type macrophage. To elucidate the effect of M1‑type macrophages induced by endostatin on melanoma B16 cells, the present study transfected RAW264.7 cells with pEndostatin plasmid and co‑cultured them with B16 cells. Compared with the control group, the expression of matrix metalloproteinase (MMP)‑2, MMP‑9 and proliferating cell nuclear antigen in B16 cells was inhibited by M1‑type macrophages, but cleaved Caspase‑3 and cleaved Caspase‑8 were significantly upregulated and the ratio of Bax/Bcl‑2 was increased. These results indicated that M1 macrophages induced by pEndostatin plasmid inhibited the proliferation and migration of B16 cells and promoted their apoptosis. These findings suggest that the inhibitory effect of endostatin on melanoma is not limited to directly inhibiting tumor microvessel formation, but it may also be related to regulating changes in macrophage polarity.

Cancer Extracellular Matrix Proteins Regulate Tumour Immunity

The extracellular matrix (ECM) plays an increasingly recognised role in the development and progression of cancer. Whilst significant progress has been made in targeting aspects of the tumour microenvironment such as tumour immunity and angiogenesis, there are no therapies that address the cancer ECM. Importantly, immune function relies heavily on the structure, physics and composition of the ECM, indicating that cancer ECM and immunity are mechanistically inseparable. In this review we highlight mechanisms by which the ECM shapes tumour immunity, identifying potential therapeutic targets within the ECM. These data indicate that to fully realise the potential of cancer immunotherapy, the cancer ECM requires simultaneous consideration.

Synergic effect of PD-1 blockade and endostar on the PI3K/AKT/mTOR-mediated autophagy and angiogenesis in Lewis lung carcinoma mouse model

BACKGROUND

Immunotherapy has been shown to be effective as a first-line treatment option for non-small cell lung cancer (NSCLC) patients. Unfortunately, it has failed to acquire an anticipant anti-tumour effect for relatively lower clinical benefit rates. It is therefore important to identify novel strategies for improving immunotherapy. Endostar is a novel recombinant human endostatin that exerts its anti-angiogenic effects via vascular endothelial growth factor (VEGF)-related signalling pathways. Anti-programmed death receptor 1 (PD-1) antibody is an immune checkpoint inhibitor that was developed to stimulate the immune system. In this study, the synergy of PD-1 blockade and endostar was assessed in a lung carcinoma mouse model.

METHODS

Lewis lung carcinoma (LLC)-bearing mice were randomly assigned into three groups: controls, anti-PD-1 and anti-PD-1+endostar. The levels of cytokines such as interleukin (IL)-17, transforming growth factor-β1 (TGF-β1) and interferon-γ (IFN-γ) were measured with enzyme-linked immune sorbent assay (ELISA). The expression of VEGF, CD34 and CD31 was assessed with immunohistochemistry (IHC). The proportion of mature dendritic cells (mDC) and myeloid-derived suppressor cells (MDSC) was analysed with flow cytometry. The major proteins in PI3K/AKT/mTOR and autophagy were quantified with Western blot.

RESULTS

Anti-PD-1 combined with endostar dramatically suppressed tumour growth in LLC mouse models. This synergistic effect resulted in decreased pro-inflammatory cytokine IL-17 and immunosuppressive factor TGF-β1 levels, increased IFN-γ secretion, reduced myeloid-derived suppressor cell (MDSC) accumulation, and reversed CD8 + T cell suppression. The expression of VEGF, CD34 and CD31 was significantly down-regulated, while tumour cell apoptosis and PI3K/AKT/mTOR-mediated autophagy was up-regulated.

CONCLUSION

The combination of anti-PD-1 and endostar has a remarkably synergic effect on LLC tumour growth by means of improving the tumour microenvironment and activating autophagy.

Impact of 5-Fu/oxaliplatin on mouse dendritic cells and synergetic effect with a colon cancer vaccine

Objective

The aim of the present study was to investigate the effects of 5-fluorouracil (5-Fu) and oxaliplatin on the function and activation pathways of mouse dendritic cells (DCs), and to clarify whether 5-Fu/oxaliplatin combined with the CD1d-MC38/α-galactosylceramide (α-GC) tumor vaccine exhibits synergistic effects on the treatment of colon cancer in mice.

Methods

The combination of the Toll like receptor (TLR) ligands and/or 5-Fu/oxaliplatin was added into myeloid-derived DCs in vitro culture. DC phenotypic changes were detected by flow cytometry, and the secretion of DC cytokines was detected by cytometric bead array (CBA). A MC38 mouse colon cancer model was constructed and the DCs were isolated from the spleen, tumor tissue and lymph nodes following intraperitoneal injection of 5-Fu/oxaliplatin. The cell phenotypes were detected by flow cytometry. The tumor infiltrating leukocytes, splenocytes and lymph node cells were co-cultured with the dead MC38 tumor cells, and the secretion levels of interferon-γ (IFN-γ) were detected. 5-Fu/oxaliplatin combined with our previously developed CD1d-MC38/α-GC tumor vaccine was used to inhibit the growth of MC38 colon cancer in mice, and the tumor growth rate and survival time were recorded.

Results

5-Fu/oxaliplatin exerted no significant effect on the expression of the stimulating phenotypes of DCs in vitro, while it could reduce the expression of programmed death ligand 1/2 (PD-L1/L2) and promote interleukin-12 (IL-12) secretion by DCs. Furthermore 5-Fu/oxaliplatin was beneficial to the differentiation of T-helper 1 (Th1) cells. 5-Fu/oxaliplatin further enhanced the stimulating phenotypic expression of DCs in tumor bearing mice, decreased PD-L1/L2 expression, and specifically activated the lymphocytes. The CD1d-MC38/α-GC tumor vaccine combined with 5-Fu/oxaliplatin could exert a synergistic role that resulted in a significant delay of the tumor growth rate, and an increase in the survival time of tumor bearing mice.

Conclusions

5-Fu/oxaliplatin decreased the expression of the DC inhibitory phenotypes PD-L1/L2, promoted DC phenotypic maturation in tumor bearing mice, activated the lymphocytes of tumor bearing mice, and exerted synergistic effects with the CD1d-MC38/α-GC colon cancer tumor vaccine.

Role of interleukin (IL)-17 and T-helper (Th)17 cells in cancer

Interleukin-17 (IL-17), a pleiotropic proinflammatory cytokine, is reported to be significantly generated by a distinct subset of CD4⁺ T-cells, upgrading cancer-elicited inflammation and preventing cancer cells from immune surveillance. T-helper (Th)17 cells produced from naive CD4⁺ T cells have recently been renowned and generally accepted, gaining eminence in cancer studies and playing the effective role in context of cancer. Th17 cells are the main source of IL-17-secreting cells, It was found that other cell types produced this cytokine as well, including Group 3 innate lymphoid cells (ILC3), δγT cells, invariant natural killer T (iNKT) cells, lymphoid-tissue inducer (LTi)-like cells and Natural killer (NK) cells. Th17-associated cytokines give impetus to tumor progression, or inducing angiogenesis and metastasis. This review demonstrates an understanding on how the pro- or antitumor function of Th17 cells and IL-17 may change cancer progression, leading to the appearance of complex and pivotal biologic activities in tumor.