Role of therapeutic agents on repolarisation of tumour-associated macrophage to halt lung cancer progression

Macrophage Polarization: An Important Candidate Regulator for Lung Diseases

Macrophages are crucial components of the immune system and play a critical role in the initial defense against pathogens. They are highly heterogeneous and plastic and can be polarized into classically activated macrophages (M1) or selectively activated macrophages (M2) in response to local microenvironments. Macrophage polarization involves the regulation of multiple signaling pathways and transcription factors. Here, we focused on the origin of macrophages, the phenotype and polarization of macrophages, as well as the signaling pathways associated with macrophage polarization. We also highlighted the role of macrophage polarization in lung diseases. We intend to enhance the understanding of the functions and immunomodulatory features of macrophages. Based on our review, we believe that targeting macrophage phenotypes is a viable and promising strategy for treating lung diseases.

Recent progress in molecular mechanisms of postoperative recurrence and metastasis of hepatocellular carcinoma

Hepatectomy is currently considered the most effective option for treating patients with early and intermediate hepatocellular carcinoma (HCC). Unfortunately, the postoperative prognosis of patients with HCC remains unsatisfactory, predominantly because of high postoperative metastasis and recurrence rates. Therefore, research on the molecular mechanisms of postoperative HCC metastasis and recurrence will help develop effective intervention measures to prevent or delay HCC metastasis and recurrence and to improve the long-term survival of HCC patients. Herein, we review the latest research progress on the molecular mechanisms underlying postoperative HCC metastasis and recurrence to lay a foundation for improving the understanding of HCC metastasis and recurrence and for developing more precise prevention and intervention strategies.

Nanotechnology-Based siRNA Delivery Systems to Overcome Tumor Immune Evasion in Cancer Immunotherapy

Immune evasion is a common reason causing the failure of anticancer immune therapy. Small interfering RNA (siRNA), which can activate the innate and adaptive immune system responses by silencing immune-relevant genes, have been demonstrated to be a powerful tool for preventing or reversing immune evasion. However, siRNAs show poor stability in biological fluids and cannot efficiently cross cell membranes. Nanotechnology has shown great potential for intracellular siRNA delivery in recent years. Nano-immunotherapy can efficiently penetrate the tumor microenvironment (TME) and deliver multiple immunomodulatory agents simultaneously, which appears to be a promising method for combination therapy. Therefore, it provides a new perspective for siRNA delivery in immunomodulation and cancer immunotherapy. The current advances and challenges in nanotechnology-based siRNA delivery strategies for overcoming immune evasion will be discussed in this review. In addition, we also offer insights into therapeutic options, which may expand its applications in clinical cancer treatment.

Tumor Associated Macrophages and TAMs-Based Anti-Tumor Nanomedicines

As an important part of tumor microenvironment, tumor associated macrophages (TAMs) play a vital role in the occurrence, development, invasion, and metastasis of many malignant tumors and can significantly promote the formation of tumor blood vessels and lymphatic vessels, hence TAMs are greatly associated with poor prognosis. The research on nanomedicine has achieved huge progress, and nano-drugs have been widely utilized to treat various diseases through different mechanisms. Therefore, developing nano-drugs that are based on TAMs-associated anti-tumor mechanisms to effectively suppress tumor growth is expected to be a promising research filed. This paper introduces relevant information about TAMs in terms of their origin, and their roles in tumor genesis, development and metastasis. Furthermore, TAMs-related anti-tumor nano-drugs are summarized. Specifically, a wide range of nano-drugs targeting at TAMs are introduced, and categorized according to their therapeutic mechanisms toward tumors. Additionally, various nano delivery platforms using TAMs as cell carriers which aim at inhibiting tumor growth are reviewed. These two parts elucidate that the exploration of nanomedicine is essential to the study on TAMs-related anti-tumor strategies. This review is also intended to provide novel ideas for in-depth investigation on anti-tumor molecular mechanisms and nano-drug delivery systems based on TAMs.

Homogeneous polyporus polysaccharide inhibits bladder cancer by polarizing macrophages to M1 subtype in tumor microenvironment

Background

Polyporus polysaccharide (PPS), an active ingredient of traditional Chinese medicinal Polyporus umbellatus, has multiple biological functions, such as anti-cancer, immune-regulating and hepatoprotective activities. The purpose of this study was to investigate the mechanism of homogeneous polyporus polysaccharide (HPP) activated macrophages in the treatment of bladder cancer.

Methods

100 ng/mL Phorbol myristate acetate (PMA) was used to induce THP-1 human leukemic cells as a macrophage model. Then macrophages derived from THP-1 were treated with different concentrations of HPP (1, 10 and 100 μg/mL). Flow cytometry and RT-PCR were used to detected the expression of CD16, CD23, CD86, CD40 and interleukin (IL)-Iβ, iNOS mRNA. ELISA was used to test the change of IL-1β and TNF-α in macrophage after the treatment with HPP. The conditioned medium from HPP-polarized macrophages was used to detect the effect of activated macrophages on bladder cancer. MTT assay, 5-ethynyl-2′-deoxyuridine assay, flow cytometry, Transwell assay, and Western blot analysis were used to detect the effects of polarized macrophages on the viability, proliferation, apoptosis, and migration of bladder cancer cells. Western blot was also used to analysis the change of JAK2/NF-κB pathway protein.

Results

HPP promoted the expression of pro-inflammatory factors, such as IL-Iβ, TNF-α and iNOS, and surface molecules CD86, CD16, CD23, and CD40 in macrophages and then polarized macrophages to M1 type. Results demonstrated that activated macrophages inhibited the proliferation of bladder cancer cells, regulated their apoptosis, and inhibited migration and epithelial–mesenchymal transformation (EMT). JAK2/NF-κB pathways were downregulated in the anti-bladder cancer process of activated macrophages.

Conclusion

The findings indicated that HPP inhibited the proliferation and progression of bladder cancer by the polarization of macrophages to M1 type, and JAK2/NF-κB pathway was downregulated in the process of anti-bladder cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03318-x.

The role of tumor-associated macrophages in osteosarcoma progression - therapeutic implications

BACKGROUND

Osteosarcoma (OS) is the most common primary malignant bone tumor. Compared with previous treatment modalities, such as amputation, more recent comprehensive treatment modalities based on neoadjuvant chemotherapy combined with limb salvage surgery have improved the survival rates of patients. Osteosarcoma treatment has, however, not further improved in recent years. Therefore, attention has shifted to the tumor microenvironment (TME) in which osteosarcoma cells are embedded. Therapeutic targets in the TME may be key to improving osteosarcoma treatment. Tumor-associated macrophages (TAMs) are the most common immune cells within the TME. TAMs in osteosarcoma may account for over 50% of the immune cells, and may play important roles in tumorigenesis, angiogenesis, immunosuppression, drug resistance and metastasis. Knowledge on the role of TAMs in the development, progression and treatment of osteosarcoma is gradually improving, although different or even opposing opinions still remain.

CONCLUSIONS

TAMs may participate in the malignant progression of osteosarcoma through self-polarization, the promotion of blood vessel and lymphatic vessel formation, immunosuppression, and drug resistance. Besides, various immune checkpoint proteins expressed on the surface of TAMs, such as PD-1 and CD47, provide the possibility of the application of immune checkpoint inhibitors. Several clinical trials have been carried out and/or are in progress. Mifamotide and the immune checkpoint inhibitor Camrelizumab were both found to be effective in prolonging progression-free survival. Thus, TAMs may serve as attractive therapeutic targets. Targeting TAMs as a complementary therapy is expected to improve the prognosis of osteosarcoma. Further efforts may be made to identify potential beneficiaries of TAM-targeted therapies.

Nanomedicine enables spatiotemporally regulating macrophage-based cancer immunotherapy

Cancer immunotherapy, leveraging the host's coordinated immune system to fight against tumor has been clinically validated. However, the modest response owing to the multiple ways of tumor immune evasion is one of the challenges in cancer immunotherapy. Tumor associated macrophages (TAMs), as a major component of the leukocytes infiltrating in all tumors, play crucial roles in driving cancer initiation, progress and metastasis via multiple mechanisms such as mediating chronic inflammation, promoting angiogenesis, taming protective immune responses, and supporting migration and intravasation. TAMs targeted therapeutics have achieved remarkable successes in clinical trials mostly through the use of small-molecule agents and antibodies. However, efforts for further application have met with challenges of limited efficacy and safety. Nanomaterials can provide versatile approaches to realize the superior spatiotemporal control over immunomodulation to amplify immune responses, ultimately enhancing the therapeutic benefits and reducing toxicity. Here, the potential drugs used in TAM-centered cancer treatment in clinic are summarized and the recent advances of TAMs targeted nanomedicines in this filed are highlighted. More importantly, we focus on how nanomedicine can exert their advantages in spatial and temporal control of immunomodulation.

Formulation Design, Statistical Optimization, and In Vitro Evaluation of a Naringenin Nanoemulsion to Enhance Apoptotic Activity in A549 Lung Cancer Cells

Naringenin (NAR), a flavonoid mainly found in citrus and grapefruits, has proven anti-cancer activities. However, the poor water solubility and low bioavailability of NAR limits its use as a therapeutic agent. The aim of this study was to develop and optimize stable naringenin nanoemulsions (NAR-NE) using a Box-Behnken experimental design to obtain a formulation with a higher efficiency. Anticancer activity of optimized NAR-NE was evaluated in A549 lung cancer cells using cell viability, flow-cytometric assays, and enzyme-linked immunosorbent assay. The stabilized nanoemulsion, which showed a spherical surface morphology, had a globule size of 85.6 ± 2.1 nm, a polydispersity index of 0.263 ± 0.02, a zeta potential of -9.6 ± 1.2 mV, and a drug content of 97.34 ± 1.3%. The NAR release from the nanoemulsion showed an initial burst release followed by a stable and controlled release for a longer period of 24 h. The nanoemulsion exhibited excellent thermodynamic and physical stability against phase separation and storage. The NAR-NE showed concentration-dependent cytotoxicity in A549 lung cancer cells, which was greater than that of free NAR. The percentage of apoptotic cells and cell cycle arrest at the G2/M and pre-G1 phases induced by NAR-NE were significantly higher than those produced by free NAR (p < 0.05). NAR-NEs were more effective than the NAR solution in reducing Bcl2 expression, while increasing pro-apoptotic Bax and caspase-3 activity. Therefore, stabilized NAR-NE could be a suitable drug delivery system to enhance the effects of NAR in the treatment of lung cancer.