Research Progress on the Bone Metastasis Mechanism of Prostate Cancer and Bone-Targeted Drugs

Prostate cancer is a common male malignant tumor,and bone metastasis is one of the common complications in the late stage of prostate cancer.The mechanism of prostate cancer bone metastasis is a complex process involving multiple factors and steps.In recent years,with in-depth research on the mechanism of prostate cancer bone metastasis and the development of new drugs,important progress has been made in the treatment of prostate cancer bone metastasis.Based on this,this article introduces the mechanism of prostate cancer bone metastasis and the research progress of several bone-targeted drugs to provide reference and inspiration for future research.

Role of autophagy in tumorigenesis,metastasis,targeted therapy and drug resistance of hepatocellular carcinoma

Autophagy is a "self-degradative" process and is involved in the maintenance of cellular homeostasis and the control of cellular components by facilitating the clearance or turnover of long-lived or misfolded proteins, protein aggregates, and damaged organelles. Autophagy plays a dual role in cancer, including in tumor progression and tumor promotion, suggesting that autophagy acts as a double-edged sword in cancer cells. Liver cancer is one of the greatest leading causes of cancer death worldwide due to its high recurrence rate and poor prognosis. Especially in China, liver cancer has become one of the most common cancers due to the high infection rate of hepatitis virus. In primary liver cancer, hepatocellular carcinoma (HCC) is the most common type. Considering the perniciousness and complexity of HCC, it is essential to elucidate the function of autophagy in HCC. In this review, we summarize the physiological function of autophagy in cancer, analyze the role of autophagy in tumorigenesis and metastasis, discuss the therapeutic strategies targeting autophagy and the mechanisms of drug-resistance in HCC, and provide potential methods to circumvent resistance and combined anticancer strategies for HCC patients.

Perspectives on bone-targeted nano-drug carriers for bone tumor treatment

Bone tumour is one of most common primary cancer which exhibits cancerous osteoblastic differentiation and malignant osteoid in patients.At present,chemotherapy(pre-and post-operative)is used as a standard treatment protocol for bone tumour.However,drugs used in the treatment of bone tumour induce high toxicity to normal tissues including anaemia,neutropenia,thrombocytopenia,and heart damage which further reduce the survival rate of patients.Therefore,there is an urgent need to develop a new therapeutic approach for the treatment such that it induce maximum cell killing effect in tumor cells while sparing the healthy bone cells.In this article,some new perspectives were provided on the development of bone-targeted nano-drug carriers for bone cancer treatment.We hope such discussions wouldencourage more detailed and careful studies to support product development of bone-targeted drug carriers for bone cancer treatment.

Antibody-platinum(IV)prodrugs conjugates for targeted treatment of cutaneous squamous cell carcinoma

Antibody-drug conjugates(ADCs)are a new type of targeting antibodies that conjugate with highly toxic anticancer drugs via chemical linkers to exert high specificity and efficient killing of tumor cells,thereby attracting considerable attention in precise oncology therapy.Cetuximab(Cet)is a typical antibody that offers the benefits of good targeting and safety for individuals with advanced and inoperable cutaneous squamous cell carcinoma(cSCC);however,its anti-tumor activity is limited to a single use.Cisplatin(CisPt)shows good curative effects;however,its adverse effects and non-tumor-targeting ability are major drawbacks.In this study,we designed and developed a new ADC based on a new cytotoxic platinum(IV)prodrug(C8Pt(IV))and Cet.The so-called antibody-platinum(IV)prodrugs conjugates,named Cet-C8Pt(IV),showed excellent tumor targeting in cSCC.Specifically,it accurately delivered C8Pt(IV)into tumor cells to exert the combined anti-tumor effect of Cet and CisPt.Herein,metabolomic analysis showed that Cet-C8Pt(IV)promoted cellular apoptosis and increased DNA damage in cSCC cells by affecting the vitamin B6 metabolic pathway in tumor cells,thereby further enhancing the tumor-killing ability and providing a new strategy for clinical cancer treatment using antibody-platinum(IV)prodrugs conjugates.

Dual ligand-targeted Pluronic P123 polymeric micelles enhance the therapeutic effect of breast cancer with bone metastases

Bone metastasis secondary to breast cancer negatively impacts patient quality of life and survival.The treatment of bone metastases is challenging since many anticancer drugs are not effectively delivered to the bone to exert a therapeutic effect.To improve the treatment efficacy,we developed Pluronic P123(P123)-based polymeric micelles dually decorated with alendronate(ALN)and cancer-specific phage protein DMPGTVLP(DP-8)for targeted drug delivery to breast cancer bone metastases.Doxorubicin(DOX)was selected as the anticancer drug and was encapsulated into the hydrophobic core of the micelles with a high drug loading capacity(3.44%).The DOX-loaded polymeric micelles were spherical,123 nm in diameter on average,and exhibited a narrow size distribution.The in vitro experiments demonstrated that a pH decrease from 7.4 to 5.0 markedly accelerated DOX release.The micelles were well internalized by cultured breast cancer cells and the cell death rate of micelle-treated breast cancer cells was increased compared to that of free DOX-treated cells.Rapid binding of the micelles to hydroxyapatite(HA)microparticles indicated their high affinity for bone.P123-ALN/DP-8@DOX inhibited tumor growth and reduced bone resorption in a 3D cancer bone metastasis model.In vivo experiments using a breast cancer bone metastasis nude model demonstrated increased accumulation of the micelles in the tumor region and considerable antitumor activity with no organ-specific histological damage and minimal systemic toxicity.In conclusion,our study provided strong evidence that these pH-sensitive dual ligand-targeted polymeric micelles may be a successful treatment strategy for breast cancer bone metastasis.

Recent advances in lymphatic targeted drug delivery system for tumor metastasis

The lymphatic system has an important defensive role in the human body. The metastasis of most tumors initially spreads through the surrounding lymphatic tissue and eventually forms lymphatic metastatic tumors; the tumor cells may even transfer to other organs to form other types of tumors. Clinically, lymphatic metastatic tumors develop rapidly. Given the limitations of surgical resection and the low effectiveness of radiotherapy and chemotherapy, the treatment of lymphatic metastatic tumors remains a great challenge. Lymph node metastasis may lead to the further spread of tumors and may be predictive of the endpoint event. Under these circumstances, novel and effective lymphatic targeted drug delivery systems have been explored to improve the specificity of anticancer drugs to tumor cells in lymph nodes. In this review, we summarize the principles of lymphatic targeted drug delivery and discuss recent advances in the development of lymphatic targeted carriers.

Genetic alteration and mutation profiling of circulating cell-free tumor DNA(cfDNA) for diagnosis and targeted therapy of gastrointestinal stromal tumors

Gastrointestinal stromal tumors(GISTs) have been recognized as a biologically distinctive type of tumor,different from smooth muscle and neural tumors of the gastrointestinal tract.The identification of genetic aberrations in proto-oncogenes that drive the growth of GISTs is critical for improving the efficacy of cancer therapy by matching targeted drugs to specific mutations.Research into the oncogenic mechanisms of GISTs has found that these tumors frequently contain activating gene mutations in either platelet-derived growth factor receptor A(PDGFRA) or a receptor tyrosine protein associated with a mast cell growth factor receptor encoded by the KIT gene.Mutant cancer subpopulations have the potential to disrupt durable patient responses to molecularly targeted therapy for GISTs,yet the prevalence and size of subpopulations remain largely unexplored.Detection of the cancer subpopulations that harbor low-frequency mutant alleles of target proto-oncogenes through the use of molecular genetic methods,such as polymerase chain reaction(PCR) target amplification technology,is hampered by the high abundance of wildtype alleles,which limit the sensitivity of detection of these minor mutant alleles.This is especially true in the case of mutant tumor DNA derived "driver" and "drug-resistant" alleles that are present in the circulating cell-free tumor DNA(cfDNA) in the peripheral blood circulation of GIST patients.So-called "liquid biopsy" allows for the dynamic monitoring of the patients' tumor status during treatment using minimally invasive sampling.New methodologies,such as a technology that employs a xenonucleic acid(XNA) clamping probe to block the PCR amplification of wild-type templates,have allowed improved molecular detection of these low-frequency alleles both in tissue biopsy samples and in cfDNA.These new methodologies could be widely applied for minimally invasive molecular testing in the therapeutic management of GISTs.

Molecular mechanisms of tumor resistance to PI3K-mTOR-targeted therapy

Deregulation of the phosphatidylinositide 3-kinase(PI3K) and mammalian target of rapamycin(mTOR) signaling pathway occurs frequently in a wide range of human cancers and is a major driving force in tumorigenesis.Thus,small molecules targeting this pathway are under active development as anticancer therapeutics.Although small-molecule inhibitors of the PI3K-mTOR pathway have shown promising clinical efficacy against human cancers,the emergence of drug resistance may limit their success in the clinic.To date,several resistance mechanisms,including both PI3K-dependent and-independent mechanisms,have been described.Here,we summarize the current understanding of resistance mechanisms to PI3K-mTOR inhibitors and discuss potential strategies for overcoming resistance for potential clinical application.

Novel insights into mTOR signalling pathways: A paradigm for targeted tumor therapy

As a crucial protein kinase,the mammalian target of rapamycin(mTOR)intimately controls essential cellular processes like cell development,proliferation,metabolism,and other crucial activities.Different cancers and disorders have been linked to imbalances in mTOR's regulatory systems.Multiple mTOR inhibitor therapy has recently acquired popularity as a method of treating cancers brought on by abnormal signal transduction pathways.We also explore potential processes behind tumor cell resistance to mTOR inhibitors and suggest workarounds to overcome this challenge.We hold the potential to pioneer cutting-edge methods for tumor therapy by methodically examining the complex mTOR signaling system and its regulatory complexity.Increasing our knowledge of mTOR-related mechanisms not only creates opportunities for cutting-edge methods to target and treat cancers but also has the potential to improve patient outcomes and general quality of life significantly.This review paper explores the most recent developments in understanding mTOR signaling pathways and the use of mTOR inhibitors in treating tumors.

The Clinical Study of Multigene Combination Test to Guide Chemotherapy Combined with Targeted Therapy in Patients with Advanced Gastrointestinal Tumors

Objective:To study the clinical effects of multigene combination test to guide chemotherapy combined with targeted therapy in patients with advanced gastrointestinal tumors.Methods:The samples were selected from 60 patients with advanced gastrointestinal tumors admitted to our hospital from March 2019 to July 2020,and were divided into a study group and a control group using a random number table model;patients in the control group did not undergo genetic testing and FOLLOX4+PD-1 chemotherapy,while patients in the study group underwent TYMS,ERCC1,EGFR,and KRAS and VEGF gene expression levels test,and the sensitive treatment plan was determined based on the test results,and the clinical indexes were compared between the two groups.Results:By comparing the total effective rate,survival time,and time to disease progression of chemotherapy in the two groups,the study group has a significant advantage(P<0.05).Conclusion:The combination of chemotherapy and targeted therapy for advanced gastrointestinal tumor patients can improve the efficiency of chemotherapy and prolong the time of disease progression and survival,which is worthy of comprehensive promotion.

Targeted therapy of gastrointestinal stromal tumours

Gastrointestinal stromal tumours(GISTs) are mesen-chymal neoplasms originating in the gastrointestinal tract, usually in the stomach or the small intestine, and rarely elsewhere in the abdomen. The malignant potential of GISTs is variable ranging from small lesions with a benign behaviour to fatal sarcomas. The majo-rity of the tumours stain positively for the CD-117(KIT) and discovered on GIST-1(DOG-1 or anoctamin 1) expression, and they are characterized by the presence of a driver kinase-activating mutation in either KIT or platelet-derived growth factor receptor α. Although surgery is the primary modality of treatment, almost half of the patients have disease recurrence following surgery, which highlights the need for an effective adjuvant therapy. Traditionally, GISTs are considered chemotherapy and radiotherapy resistant. With the advent of targeted therapy(tyrosine kinase inhibitors), there has been a paradigm shift in the management of GISTs in the last decade. We present a comprehensive review of targeted therapy in the management of GISTs.

Progression of targeted therapy in advanced cholangiocarcinoma

It is necessary to establish an effective therapy to improve the survival of patients with advanced eholangiocarcinoma （CCM. Recently, with the development of pathology research in CCA, a lot of special bio-markers such as EGFR, VEGF, HER2, and MEK et al. could be over expression or mutations in CCA patients. According to their changes, combinations of targeted therapy plus chemotherapy are now recognized as effective therapies for advanced CCA. The aim of this paper is to analyze recent promising studies about targeted therapy alone or combination with each other or with chemotherapies.

Biointerface engineering nanoplatforms for cancer-targeted drug delivery

Over the past decade,nanoparticle-based therapeutic modalities have become promising strategies in cancer therapy.Selective delivery of anticancer drugs to the lesion sites is critical for elimination of the tumor and an improved prognosis.Innovative design and advanced biointerface engineering have promoted the development of various nanocarriers for optimized drug delivery.Keeping in mind the biological framework of the tumormicroenvironment,biomembrane-camouflaged nanoplatforms have been a research focus,reflecting their superiority in cancer targeting.In this review,we summarize the development of various biomimetic cell membrane-camouflaged nanoplatforms for cancertargeted drug delivery,which are classified according to the membranes fromdifferent cells.The challenges and opportunities of the advanced biointerface engineering drug delivery nanosystems in cancer therapy are discussed.

Functionalized magnetic nanoparticles for drug delivery in tumor therapy

The side effects of chemotherapy are mainly the poor control of drug release. Magnetic nanoparticles(MNPs) have super-paramagnetic behaviors which are preferred for biomedical applications such as in targeted drug delivery, besides, in magnetic recording, catalysis, and others. MNPs, due to high magnetization response, can be manipulated by the external magnetic fields to penetrate directly into the tumor, thus they can act as ideal drug carriers. MNPs also play a crucial role in drug delivery system because of their high surface-to-volume ratio and porosity. The drug delivery in tumor therapy is related to the sizes, shapes, and surface coatings of MNPs as carriers. Therefore, in this review, we first summarize the effects of the sizes, shapes, and surface coatings of MNPs on drug delivery, then discuss three types of drug release systems, i.e., p H-controlled, temperature-controlled, and magnetic-controlled drug release systems, and finally compare the principle of passive drug release with that of active drug release in tumor therapy.

Lipid metabolism of hepatocellular carcinoma impacts targeted therapy and immunotherapy

Hepatocellular carcinoma(HCC)is a common malignant tumor that affecting many people's lives globally.The common risk factors for HCC include being overweight and obese.The liver is the center of lipid metabolism,synthesizing most cholesterol and fatty acids.Abnormal lipid metabolism is a significant feature of metabolic reprogramming in HCC and affects the prognosis of HCC patients by regulating inflammatory responses and changing the immune microenvironment.Targeted therapy and immunotherapy are being explored as the primary treatment strategies for HCC patients with unresectable tumors.Here,we detail the specific changes of lipid metabolism in HCC and its impact on both these therapies for HCC.HCC treatment strategies aimed at targeting lipid metabolism and how to integrate them with targeted therapy or immunotherapy rationally are also presented.

Research Progress in Targeted Therapy of Hepatocellular Carcinoma

Hepatocellular carcinoma(HCC)is one of the most common malignancies,and its treatment is limited.With the understanding of key genes and signaling pathways in the occurrence and development of HCC,targeted drugs with high selectivity and low toxicity have been developed continuously,bringing a variety of options for the treatment of advanced HCC.In this article,the research progress on representative drugs of targeted therapy and potential therapeutic targets for HCC are reviewed.

Targeted therapy: resistance and re-sensitization

The last two decades have witnessed a paradigm shift from cytotoxic drugs to targeted therapy in medical oncol?ogy and pharmaceutical innovation. Inspired by breakthroughs in molecular and cellular biology, a number of novel synthesized chemical compounds and recombinant antibodies have been developed to selectively target oncogenic signaling pathways in a broad array of tumor types. Although targeted therapeutic agents show impressive clinical eicacy and minimized adverse efects compared with traditional treatments, the challenging drug?resistant issue has also emerged to limit their beneits to cancer patients. In this regard, we aim to improve targeted therapy by present?ing a systematic framework regarding the drug resistance mechanisms and alternative approaches to re?sensitize cancer cells/tissues therapeutically.

Targeted Thrombolytic Therapy

Venous and arterial thrombosis are closely related to many severe diseases, especially to cardiovascular and cerebrovasular disorders. Thrombolytic therapy has been proven to be an effective method to treat such disease, which decreased the mortality and morbidity greatly.

Discovering metabolic vulnerability using spatially resolved metabolomics for antitumor small molecule-drug conjugates development as a precise cancer therapy strategy

Against tumor-dependent metabolic vulnerability is an attractive strategy for tumor-targeted therapy.However,metabolic inhibitors are limited by the drug resistance of cancerous cells due to their metabolic plasticity and heterogeneity.Herein,choline metabolism was discovered by spatially resolved metabolomics analysis as metabolic vulnerability which is highly active in different cancer types,and a choline-modified strategy for small molecule-drug conjugates(SMDCs)design was developed to fool tumor cells into indiscriminately taking in choline-modified chemotherapy drugs for targeted cancer therapy,instead of directly inhibiting choline metabolism.As a proof-of-concept,choline-modified SMDCs were designed,screened,and investigated for their druggability in vitro and in vivo.This strategy improved tumor targeting,preserved tumor inhibition and reduced toxicity of paclitaxel,through targeted drug delivery to tumor by highly expressed choline transporters,and site-specific release by carboxylesterase.This study expands the strategy of targeting metabolic vulnerability and provides new ideas of developing SMDCs for precise cancer therapy.