Involvement of local renin-angiotensin system in immunosuppression of tumor microenvironment

Role of renin angiotensin system inhibitors and metformin in Glioblastoma Therapy: a review

Glioblastoma multiforme (GBM) is a highly aggressive and incurable disease accounting for about 10,000 deaths in the USA each year. Despite the current treatment approach which includes surgery with chemotherapy and radiation therapy, there remains a high prevalence of recurrence. Notable improvements have been observed in persons receiving concurrent antihypertensive drugs such as renin angiotensin inhibitors (RAS) or the antidiabetic drug metformin with standard therapy. Anti-tumoral effects of RAS inhibitors and metformin have been observed in in vitro and in vivo studies. Although clinical trials have shown mixed results, the potential for the use of RAS inhibitors and metformin as adjuvant GBM therapy remains promising. Nevertheless, evidence suggest that these drugs exert multimodal antitumor actions; by particularly targeting several cancer hallmarks. In this review, we highlight the results of clinical studies using multidrug cocktails containing RAS inhibitors and or metformin added to standard therapy for GBM. In addition, we highlight the possible molecular mechanisms by which these repurposed drugs with an excellent safety profile might elicit their anti-tumoral effects. RAS inhibition elicits anti-inflammatory, anti-angiogenic, and immune sensitivity effects in GBM. However, metformin promotes anti-migratory, anti-proliferative and pro-apoptotic effects mainly through the activation of AMP-activated protein kinase. Also, we discussed metformin's potential in targeting both GBM cells as well as GBM associated-stem cells. Finally, we summarize a few drug interactions that may cause an additive or antagonistic effect that may lead to adverse effects and influence treatment outcome.

Efficacy and safety of immune checkpoint inhibitors in solid tumor patients combined with chronic coronary syndromes or its risk factor: a nationwide multicenter cohort study

BACKGROUND

Although, immune checkpoint inhibitors (ICIs) have been widely applied in the therapy of malignant tumors, the efficacy and safety of ICIs in patients with tumors and pre-existing CAD, especially chronic coronary syndromes (CCS) or their risk factors (CRF), is not well identified.

METHODS

This was a nationwide multicenter observational study that enrolled participants who diagnosed with solid tumors and received ICIs therapy. The main efficacy indicators were progression-free survival (PFS) and overall survival (OS), followed by objective response rate (ORR) and disease control rate (DCR). Safety was assessed by describing treatment-related adverse events (TRAEs) during ICIs therapy evaluated by the Common Terminology Criteria for Adverse Events 5.0 (CTCAE 5.0).

RESULTS

In the current research, we retrospectively analyzed the data of 551 patients diagnosed with solid tumors and received ICIs therapy, and these patients were divided into CCS/CRF group and non-CCS/CRF group. Patients with CCS/CRF had more favorable PFS and OS than patients without CCS/CRF (P < 0.001) and the pre-existing CCS/CRF was a protective factor for survival. The ORR (51.8% vs. 39.1%) and DCR (95.8% vs. 89.2%) were higher in CCS/CRF group than in non-CCS/CRF group (P = 0.003, P = 0.006). In this study, there was no significant difference in treatment-related adverse events (TRAEs), including immune-related adverse events (irAEs), between the two groups.

CONCLUSIONS

We concluded that ICIs appear to have better efficacy in malignant solid tumor patients with pre-existing CCS/CRF and are not accompanied by more serious irAEs.

Concomitant use of renin-angiotensin system inhibitors augments the efficacy of immune checkpoint inhibitors: a systematic review and meta-analysis

Background

The impact of renin-angiotensin system inhibitors (RASIs) on the outcome of hypertensive cancer patients undergoing immune checkpoint inhibitor (ICIs) therapy remains ambiguous. This investigation sought to elucidate the consequences of RASIs use on the prognosis for this specific patient group within the context of ICIs treatment, aspiring to provide a clearer basis for rational, evidence-driven choices in the clinical prescription of these medications.

Methods

A comprehensive search was conducted on PubMed, Embase, Web of Science, and the Cochrane Library for original studies published up to 6 August 2023. Studies published in English reporting hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and/or progression-free survival (PFS) were included. All statistical analyses were executed utilizing R software (version 4.2.2).

Results

A total of 13 studies, encompassing approximately 12,595 patients, satisfied the inclusion criteria. Meta-analyses demonstrated a statistically significant association between the use of RASIs and a favorable outcome in OS (HR, 0.74; 95% CI, 0.62-0.88) and PFS (HR, 0.77; 95% CI, 0.62-0.96) among cancer patients receiving ICIs treatment.

Conclusion

This investigation provides compelling evidence supporting the beneficial prognostic impact of RASIs on cancer patients receiving ICIs. RASIs present a viable option as antihypertensive agents for cancer patients with hypertension undergoing ICIs treatment. Further exploration and validation through prospective studies are necessary to establish definitive guidelines for the use of RASIs in managing hypertensive cancer patients undergoing immunotherapy with ICIs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023454886.

Research on the signaling pathway and the related mechanism of traditional Chinese medicine intervention in chronic gastritis of the "inflammation-cancer transformation"

Objective: The aim of this study is to uncover the traditional Chinese medicine (TCM) treatments for chronic gastritis and their potential targets and pathways involved in the "inflammation-cancer" conversion in four stages. These findings can provide further support for future research into TCM and its active components. Materials and methods: The literature search encompassed PubMed, Web of Science, Google Scholar, CNKI, WanFang, and VIP, employing keywords such as "chronic gastritis", "gastric cancer", "traditional Chinese medicine", "medicinal herb", "Chinese herb", and "natural plant". Results: Herbal remedies may regulate the signaling pathways linked to the advancement of chronic gastritis. Under the multi-target and multi-pathway independent or combined reaction, the inflammatory microenvironment may be enhanced, leading to repair of damaged gastric mucosal cells, buffering the progress of mucosal atrophic degeneration via the decrease of inflammatory factor expression, inhibition of oxidative stress-induced damage, facilitation of microvascular neovascularization in the gastric mucosa and regulation of the processes of gastric mucosal cell differentiation and proliferation. Simultaneously, the decreased expression of inflammatory factors may impact the expression of associated oncogenes and regulate the malignant proliferation of cells, thereby achieving the treatment and prevention objectives of gastric cancer through the reduction of cell metastasis and apoptosis. Conclusion: Chinese medicine formulations and individual drugs can be utilised at various stages of the "inflammation-cancer" progression of chronic gastritis to prevent and treat gastric cancer in a multi-level, multi-targeted, and multi-directional fashion. This can provide guidance for the accurate application of medicines during different stages of "inflammation-cancer" transformation. New insights into the mechanism of inflammation-cancer transformation and the development of novel drugs for chronic gastritis can be gained through an extensive investigation of TCM treatment in this condition.

The Expression of Alamandine Receptor MrgD in Clear Cell Renal Cell Carcinoma Is Associated with a Worse Prognosis and Unfavorable Response to Antiangiogenic Therapy

Renal cell carcinoma (RCC) ranks among the most prevalent malignancies in Western countries, marked by its notable heterogeneity, which contributes to an unpredictable clinical trajectory. The insufficiency of dependable biomarkers adds complexity to assessing this tumor progression. Imbalances of several components of the intrarenal renin-angiotensin system (iRAS) significantly impact patient prognoses and responses to first-line immunotherapies. In this study, we analyzed the immunohistochemical expression of the Mas-related G-protein-coupled receptor D (MrgD), which recognizes the novel RAS peptide alamandine (ALA), in a series of 87 clear cell renal cell (CCRCCs), 19 papillary (PRCC), 7 chromophobe (ChRCC) renal cell carcinomas, and 11 renal oncocytomas (RO). MrgD was expressed in all the renal tumor subtypes, with a higher mean staining intensity in the PRCCs, ChRCCs, and ROs. A high expression of MrgD at the tumor center and at the infiltrative front of CCRCC tissues was significantly associated with a high histological grade, large tumor diameter, local invasion, and locoregional node and distant metastasis. Patients with worse 5-year cancer-specific survival and a poorer response to antiangiogenic tyrosine-kinase inhibitors (TKIs) showed higher MrgD expression at the center of their primary tumors. These findings suggest a possible role of MrgD in renal carcinogenetic processes. Further studies are necessary to unveil its potential as a novel biomarker for CCRCC prognosis and response to frontline therapies.

Genetic Variations of Angiotensinogen, Angiotensin Converting Enzyme, and Angiotensin Type 1 Receptor with the Risk of Pulmonary Tuberculosis

There is little data regarding the impact of renin-angiotensin system (RAS) gene polymorphisms on tuberculosis. The current study designed to survey the possible association between RAS polymorphisms and the risk of pulmonary tuberculosis (PTB) in a sample of the southeast Iranian population. This case-control study was done on 170 PTB patients and 170 healthy subjects. The AGT rs699 C>T, ACE rs4341 C>G and AT1R rs5186 C>A variants were genotyped using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) and ACE rs4646994 (287bp I/D) variant by PCR method. Regarding AT1R rs5186 A>C polymorphism, the findings revealed that AC genotype and C allele significantly decreased the risk of PTB (OR=0.39, 95% CI=0.22-0.67, p=0.001, and OR=0.53, 95% CI=0.25-0.72, p=0.002, C vs. A, respectively). The TC genotype and C allele of AGT rs699 T>C significantly associated with decreased the risk of PTB (OR=0.45, 95% CI=0.28-0.74, p=0.002, TC vs. TT and OR=0.51, 95% CI=0.32-0.80, p=0.005, C vs. T, respectively). The ID genotype of ACE 287bp I/D significantly increased the risk of PTB (OR=1.88, 95% CI=1.12-3.17, p=0.017). Our finding did not support an association between ACE rs4341 C>G variant and the risk of PTB. In summary, the findings revealed an association between AT1R rs5186 A>C, AGT rs699 T>C and ACE 287bp I/D polymorphisms and the risk of PTB in a sample of the southeast Iranian population. Further investigation with higher sample sizes and diverse ethnicities are required to confirm our findings.

Insights into the Tumor Microenvironment-Components, Functions and Therapeutics

Similarly to our healthy organs, the tumor tissue also constitutes an ecosystem. This implies that stromal cells acquire an altered phenotype in tandem with tumor cells, thereby promoting tumor survival. Cancer cells are fueled by abnormal blood vessels, allowing them to develop and proliferate. Tumor-associated fibroblasts adapt their cytokine and chemokine production to the needs of tumor cells and alter the peritumoral stroma by generating more collagen, thereby stiffening the matrix; these processes promote epithelial-mesenchymal transition and tumor cell invasion. Chronic inflammation and the mobilization of pro-tumorigenic inflammatory cells further facilitate tumor expansion. All of these events can impede the effective administration of tumor treatment; so, the successful inhibition of tumorous matrix remodeling could further enhance the success of antitumor therapy. Over the last decade, significant progress has been made with the introduction of novel immunotherapy that targets the inhibitory mechanisms of T cell activation. However, extensive research is also being conducted on the stromal components and other cell types of the tumor microenvironment (TME) that may serve as potential therapeutic targets.

Role of cancer-associated fibroblasts in colorectal cancer and their potential as therapeutic targets

Cancer-associated fibroblasts (CAFs) are mesenchymal cells in the tumor microenvironment (TME). CAFs are the most abundant cellular components in the TME of solid tumors. They affect the progression and course of chemotherapy and radiotherapy in various types of tumors including colorectal cancer (CRC). CAFs can promote tumor proliferation, invasion, and metastasis; protect tumor cells from immune surveillance; and resist tumor cell apoptosis caused by chemotherapy, resulting in drug resistance to chemotherapy. In recent years, researchers have become increasingly interested CAF functions and have conducted extensive research. However, compared to other types of malignancies, our understanding of the interaction between CRC cells and CAFs remains limited. Therefore, we searched the relevant literature published in the past 10 years, and reviewed the origin, biological characteristics, heterogeneity, role in the TME, and potential therapeutic targets of CAFs, to aid future research on CAFs and tumors.

Charting a killer course to the solid tumor: strategies to recruit and activate NK cells in the tumor microenvironment

The ability to expand and activate natural Killer (NK) cells ex vivo has dramatically changed the landscape in the development of novel adoptive cell therapies for treating cancer over the last decade. NK cells have become a key player for cancer immunotherapy due to their innate ability to kill malignant cells while not harming healthy cells, allowing their potential use as an "off-the-shelf" product. Furthermore, recent advancements in NK cell genetic engineering methods have enabled the efficient generation of chimeric antigen receptor (CAR)-expressing NK cells that can exert both CAR-dependent and antigen-independent killing. Clinically, CAR-NK cells have shown promising efficacy and safety for treating CD19-expressing hematologic malignancies. While the number of pre-clinical studies using CAR-NK cells continues to expand, it is evident that solid tumors pose a unique challenge to NK cell-based adoptive cell therapies. Major barriers for efficacy include low NK cell trafficking and infiltration into solid tumor sites, low persistence, and immunosuppression by the harsh solid tumor microenvironment (TME). In this review we discuss the barriers posed by the solid tumor that prevent immune cell trafficking and NK cell effector functions. We then discuss promising strategies to enhance NK cell infiltration into solid tumor sites and activation within the TME. This includes NK cell-intrinsic and -extrinsic mechanisms such as NK cell engineering to resist TME-mediated inhibition and use of tumor-targeted agents such as oncolytic viruses expressing chemoattracting and activating payloads. We then discuss opportunities and challenges for using combination therapies to extend NK cell therapies for the treatment of solid tumors.

The renin-angiotensin-aldosterone system (RAAS) signaling pathways and cancer: foes versus allies

The renin-angiotensin-aldosterone system (RAAS), is an old system with new fundamental roles in cancer biology which influences cell growth, migration, death, and metastasis. RAAS signaling enhances cell proliferation in malignancy directly and indirectly by affecting tumor cells and modulating angiogenesis. Cancer development may be influenced by the balance between the ACE/Ang II/AT1R and the ACE2/Ang 1-7/Mas receptor pathways. The interactions between Ang II/AT1R and Ang I/AT2R as well as Ang1-7/Mas and alamandine/MrgD receptors in the RAAS pathway can significantly impact the development of cancer. Ang I/AT2R, Ang1-7/Mas, and alamandine/MrgD interactions can have anticancer effects while Ang II/AT1R interactions can be involved in the development of cancer. Evidence suggests that inhibitors of the RAAS, which are conventionally used to treat cardiovascular diseases, may be beneficial in cancer therapies.Herein, we aim to provide a thorough description of the elements of RAAS and their molecular play in cancer. Alongside this, the role of RAAS components in sex-dependent cancers as well as GI cancers will be discussed with the hope of enlightening new venues for adjuvant cancer treatment.

Strategy of targeting the tumor microenvironment via inhibition of fibroblast/fibrosis remodeling new era to cancer chemo-immunotherapy resistance

The use of repurposing drugs that may have neoplastic and anticancer effects increases the efficiency and decrease resistance to chemotherapy drugs through a biochemical and mechanical transduction mechanisms through modulation of fibroblast/fibrosis remodeling in tumor microenvironment (TME). Interestingly, fibroblast/fibrosis remodeling plays a vital role in mediating cancer metastasis and drug resistance after immune chemotherapy. The most essential hypothesis for induction of chemo-immunotherapy resistance is via activation of fibroblast/fibrosis remodeling and preventing the infiltration of T cells after is mainly due to the interference between cytoskeleton, mechanical, biochemical, metabolic, vascular, and remodeling signaling pathways in TME. The structural components of the tumor that can be targeted in the fibroblast/fibrosis remodeling include the depletion of the TME components, targeting the cancer-associated fibroblasts and tumor associated macrophages, alleviating the mechanical stress within the ECM, and normalizing the blood vessels. It has also been found that during immune-chemotherapy, TME injury and fibroblast/fibrosis remodeling causes the up-regulation of inhibitory signals and down-regulation of activated signals, which results in immune escape or chemo-resistance of the tumor. In this regard, repurposing or neo-adjuvant drugs with various transduction signaling mechanisms, including anti-fibrotic effects, are used to target the TME and fibroblast/fibrosis signaling pathway such as angiotensin 2, transforming growth factor-beta, physical barriers of the TME, cytokines and metabolic factors which finally led to the reverse of the chemo-resistance. Consistent to many repurposing drugs such as pirfenidone, metformin, losartan, tranilast, dexamethasone and pentoxifylline are used to decrease immune-suppression by abrogation of TME inhibitory signal that stimulates the immune system and increases efficiency and reduces resistance to chemotherapy drugs. To overcome immunosuppression based on fibroblast/fibrosis remodeling, in this review, we focus on inhibitory signal transduction, which is the physical barrier, alleviates mechanical stress and prevents mechano-metabolic activation.

The role of gut microbiota and drug interactions in the development of colorectal cancer

The human gut microbiota is a complex ecosystem regulating the host's environmental interaction. The same functional food or drug may have varying bioavailability and distinct effects on different individuals. Drugs such as antibiotics can alter the intestinal flora, thus affecting health. However, the relationship between intestinal flora and non-antibiotic drugs is bidirectional: it is not only affected by drugs; nevertheless, it can alter the drug structure through enzymes and change the bioavailability, biological activity, or toxicity of drugs to improve their efficacy and safety. This review summarizes the roles and mechanisms of antibiotics, antihypertensive drugs, nonsteroidal anti-inflammatory drugs, lipid-lowering drugs, hypoglycemic drugs, virus-associated therapies, metabolites, and dietary in modulating the colorectal cancer gut microbiota. It provides a reference for future antitumor therapy targeting intestinal microorganisms.

Drug Repurposing to Circumvent Immune Checkpoint Inhibitor Resistance in Cancer Immunotherapy

Immune checkpoint inhibitors (ICI) have achieved unprecedented clinical success in cancer treatment. However, drug resistance to ICI therapy is a major hurdle that prevents cancer patients from responding to the treatment or having durable disease control. Drug repurposing refers to the application of clinically approved drugs, with characterized pharmacological properties and known adverse effect profiles, to new indications. It has also emerged as a promising strategy to overcome drug resistance. In this review, we summarized the latest research about drug repurposing to overcome ICI resistance. Repurposed drugs work by either exerting immunostimulatory activities or abolishing the immunosuppressive tumor microenvironment (TME). Compared to the de novo drug design strategy, they provide novel and affordable treatment options to enhance cancer immunotherapy that can be readily evaluated in the clinic. Biomarkers are exploited to identify the right patient population to benefit from the repurposed drugs and drug combinations. Phenotypic screening of chemical libraries has been conducted to search for T-cell-modifying drugs. Genomics and integrated bioinformatics analysis, artificial intelligence, machine and deep learning approaches are employed to identify novel modulators of the immunosuppressive TME.

Comedications with Immune Checkpoint Inhibitors: Involvement of the Microbiota, Impact on Efficacy and Practical Implications

Immune checkpoint inhibitors (ICIs) have been a major breakthrough in solid oncology over the past decade. The immune system and the gut microbiota are involved in their complex mechanisms of action. However, drug interactions have been suspected of disrupting the fine equilibrium necessary for optimal ICI efficacy. Thus, clinicians are facing a great deal of sometimes contradictory information on comedications with ICIs and must at times oppose conflicting objectives between oncological response and comorbidities or complications. We compiled in this review published data on the role of the microbiota in ICI efficacy and the impact of comedications. We found mostly concordant results on detrimental action of concurrent corticosteroids, antibiotics, and proton pump inhibitors. The timeframe seems to be an important variable each time to preserve an initial immune priming at ICIs initiation. Other molecules have been associated with improved or impaired ICIs outcomes in pre-clinical models with discordant conclusions in retrospective clinical studies. We gathered the results of the main studies concerning metformin, aspirin, and non-steroidal anti-inflammatory drugs, beta blockers, renin-angiotensin-aldosterone system inhibitors, opioids, and statins. In conclusion, one should always assess the necessity of concomitant treatment according to evidence-based recommendations and discuss the possibility of postponing ICI initiation or switching strategies to preserve the critical window.

Angiotensin receptor blockers retard the progression and fibrosis via inhibiting the viability of AGTR1+ CAFs in intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (iCCA) is a highly lethal malignancy characterized by massive fibrosis and has ineffective adjuvant therapies. Here, we demonstrate the potential of angiotensin receptor blockers (ARBs) in targeting iCCA.

METHODS

Masson's trichrome staining was used to assess the effect of ARBs in iCCA specimens, CCK8 and gel contraction assays in vitro and in xenograft models in vivo. RNA-seq and ATAC-seq were used for mechanistic investigations.

RESULTS

Patients with iCCA who were administered ARBs had a better prognosis and a lower proportion of tumour stroma, indicating alleviated fibrosis. The presence of AGTR1, the ARBs receptor, is associated with a poor prognosis of iCCA and is highly expressed in tumour tissues and cancer-associated fibroblasts (CAFs). The ARBs strongly attenuated the viability of AGTR1+ CAFs in vitro and retarded tumour progression and fibrosis in xenograft models of co-cultured CAFs and iCCA cells. Still, they did not have a significant effect on AGTR1- CAFs. Moreover, ARBs decreased the secretion of AGTR1+ CAF-derived MFAP5 via the Hippo pathway, weakened the interaction between CAFs and iCCA cells, and impaired the aggressiveness of iCCA cells by attenuating the activation of the Notch1 pathway in iCCA cells.

CONCLUSIONS

ARBs exhibit anti-fibrotic function by inhibiting the viability of AGTR1+ CAFs. These findings support using ARBs as a novel therapeutic option for targeting iCCA.

Melanoma antigens recognized by T cells and their use for immunotherapy

Melanoma has been a prototype for cancer immunology research, and the mechanisms of anti-tumor T-cell responses have been extensively investigated in patients treated with various immunotherapies. Individual differences in cancer-immune status are defined mainly by cancer cell characteristics such as DNA mutations generating immunogenic neo-antigens, and oncogene activation causing immunosuppression, but also by patients' genetic backgrounds such as HLA types and genetic polymorphisms of immune related molecules, and environmental and lifestyle factors such as UV rays, smoking, gut microbiota and concomitant medications; these factors have an influence on the efficacy of immunotherapy. Recent comparative studies on responders and non-responders in immune-checkpoint inhibitor therapy using various new technologies including multi-omics analyses on genomic DNA, mRNA, metabolites and microbiota and single cell analyses of various immune cells have led to the advance of human tumor immunology and the development of new immunotherapy. Based on the new findings from these investigations, personalized cancer immunotherapies along with appropriate biomarkers and therapeutic targets are being developed for patients with melanoma. Here, we will discuss one of the essential subjects in tumor immunology: identification of immunogenic tumor antigens and their effective use in various immunotherapies including cancer vaccines and adoptive T-cell therapy.

Clinical Significance and Tumor Microenvironment Characterization of a Novel Immune-Related Gene Signature in Bladder Cancer

Cancer immunotherapy plays a crucial role in bladder cancer (BC) progression. Increasing evidence has elucidated the clinicopathologic significance of the tumor microenvironment (TME) in predicting outcomes and therapeutic efficacy. This study sought to establish a comprehensive analysis of the immune-gene signature combined with TME to assist in BC prognosis. We selected sixteen immune-related genes (IRGs) after a weighted gene co-expression network and survival analysis. Enrichment analysis revealed that these IRGs were actively involved in Mitophagy and Renin secretion pathways. After multivariable COX analysis, the IRGPI comprising NCAM1, CNTN1, PTGIS, ADRB3, and ANLN was established to predict the overall survival of BC, which was validated in both TCGA and GSE13507 cohorts. In addition, a TME gene signature was developed for molecular and prognosis subtyping with unsupervised clustering, followed by a panoramic landscape characterization of BC. In summary, the IRGPI model developed in our study provided a valuable tool with an improved prognosis for BC.

Molecular differences of angiogenic versus vessel co-opting colorectal cancer liver metastases at single-cell resolution

BACKGROUND

Colorectal cancer liver metastases (CRCLM) are associated with a poor prognosis, reflected by a five-year survival rate of 14%. Anti-angiogenic therapy through anti-VEGF antibody administration is one of the limited therapies available. However, only a subgroup of metastases uses sprouting angiogenesis to secure their nutrients and oxygen supply, while others rely on vessel co-option (VCO). The distinct mode of vascularization is reflected by specific histopathological growth patterns (HGPs), which have proven prognostic and predictive significance. Nevertheless, their molecular mechanisms are poorly understood.

METHODS

We evaluated CRCLM from 225 patients regarding their HGP and clinical data. Moreover, we performed spatial (21,804 spots) and single-cell (22,419 cells) RNA sequencing analyses to explore molecular differences in detail, further validated in vitro through immunohistochemical analysis and patient-derived organoid cultures.

RESULTS

We detected specific metabolic alterations and a signature of WNT signalling activation in metastatic cancer cells related to the VCO phenotype. Importantly, in the corresponding healthy liver of CRCLM displaying sprouting angiogenesis, we identified a predominantly expressed capillary subtype of endothelial cells, which could be further explored as a possible predictor for HGP relying on sprouting angiogenesis.

CONCLUSION

These findings may prove to be novel therapeutic targets to the treatment of CRCLM, in special the ones relying on VCO.

Effect of renin-angiotensin-aldosterone system inhibitors on survival outcomes in cancer patients treated with immune checkpoint inhibitors: a systematic review and meta-analysis

Background

Effect of renin-angiotensin-aldosterone system inhibitors (RAASIs) in combination with immune checkpoint inhibitors (ICIs) on prognoses in cancer patients remains controversial. This study systematically evaluated the effect of RAASIs on survival outcomes in cancer patients receiving ICIs treatment and provided an evidence-based reference for the rational use of RAASIs and ICIs combination therapy in clinical practice.

Methods

Studies evaluating the prognosis of RAASIs-used versus RAASIs-free in cancer patients receiving ICIs treatment from inception to 1 November 2022 were retrieved by searching PubMed, Cochrane Library, Web of Science, Embase, and major conference proceedings. Studies in English reporting hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) and/or progression-free survival (PFS) were included. Statistical analyses were conducted using the software Stata 17.0.

Results

A total of 12 studies containing 11739 patients were included, comprising ~4861 patients in the RAASIs-used and ICIs-treated group and ~6878 patients in RAASIs-free and ICIs-treated group. The pooled HR was 0.85 (95%CI, 0.75-0.96; P = 0.009) for OS and 0.91 (95%CI, 0.76-1.09; P = 0.296) for PFS, indicating a positive effect of RAASIs concomitant with ICIs on cancer patients. This effect was observed especially in patients with urothelial carcinoma (HR, 0.53; 95%CI, 0.31-0.89; P = 0.018) and renal cell carcinoma (HR, 0.56; 95%CI, 0.37-0.84; P = 0.005) on OS.

Conclusion

Concomitant use of RAASIs and ICIs enhanced the efficacy of ICIs and this combination regimen was associated with significantly improved OS and a trend towards better PFS. RAASIs can be considered as adjuvant drugs when hypertensive patients receive ICIs treatment. Our results provide an evidence-based reference for the rational use of the RAASIs and ICIs combination therapy to improve the efficacy of ICIs in clinical practice.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022372636; https://inplasy.com/, identifier INPLASY2022110136.

Impact of renin-angiotensin system inhibitors on the survival of patients with rectal cancer

Background

Renin-angiotensin system inhibitors (RASIs) are widely used in the treatment of hypertension. However, their impact on the outcome of the combined treatment of rectal cancer is poorly understood. The aim of this study was to assess the effect of RASIs on the survival of rectal cancer patients with associated hypertension after neoadjuvant treatment and radical resection.

Methods

Between 2008 and 2016, 242 radical (R0) rectal resections for cancer were performed after neoadjuvant treatment in patients with associated hypertension. At the time of treatment, 158 patients were on RASIs, including 35 angiotensin-receptor antagonists (ARB) users and 123 angiotensin-converting enzyme inhibitors (ACEI) users. Eighty-four patients were on drugs other than RASIs (non-RASI users). The survival analysis was performed using the Kaplan–Meier estimator with the log-rank test and the Cox proportional hazards model.

Results

The log-rank test showed a significantly worse overall survival (OS) in the group of ACEI users compared to ARB users (p = 0.009) and non-RASI users (p = 0.013). Disease-free survival (DFS) was better in the group of ARB users compared to ACEI users. However, the difference was not statistically significant (p = 0.064). The Multivariate Cox analysis showed a significant beneficial effect of ARBs on OS (HR: 0.326, 95% CI: 0.147–0.724, p = 0.006) and ARBs on DFS (HR: 0.339, 95% CI: 0.135–0.850, p = 0.021) compared to ACEIs. Other factors affecting OS included age (HR: 1.044, 95% CI: 1.016–1.073, p = 0.002), regional lymph node metastasis (ypN +) (HR: 2.157, 95% CI: 1.395–3.334, p = 0.001) and perineural invasion (PNI) (HR: 3.864, 95% CI: 1.799–8.301, p = 0.001). Additional factors affecting DFS included ypN + (HR: 2.310, 95% CI: 1.374–3.883, p = 0.002) and PNI (HR: 4.351, 95% CI: 1.584–11.954, p = 0.004).

Conclusions

The use of ARBs instead of ACEIs may improve the outcome of the combined therapy for rectal cancer patients with associated hypertension.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09919-0.

MDACT: A New Principle of Adjunctive Cancer Treatment Using Combinations of Multiple Repurposed Drugs, with an Example Regimen

In part one of this two-part paper, we present eight principles that we believe must be considered for more effective treatment of the currently incurable cancers. These are addressed by multidrug adjunctive cancer treatment (MDACT), which uses multiple repurposed non-oncology drugs, not primarily to kill malignant cells, but rather to reduce the malignant cells' growth drives. Previous multidrug regimens have used MDACT principles, e.g., the CUSP9v3 glioblastoma treatment. MDACT is an amalgam of (1) the principle that to be effective in stopping a chain of events leading to an undesired outcome, one must break more than one link; (2) the principle of Palmer et al. of achieving fractional cancer cell killing via multiple drugs with independent mechanisms of action; (3) the principle of shaping versus decisive operations, both being required for successful cancer treatment; (4) an idea adapted from Chow et al., of using multiple cytotoxic medicines at low doses; (5) the idea behind CUSP9v3, using many non-oncology CNS-penetrant drugs from general medical practice, repurposed to block tumor survival paths; (6) the concept from chess that every move creates weaknesses and strengths; (7) the principle of mass-by adding force to a given effort, the chances of achieving the goal increase; and (8) the principle of blocking parallel signaling pathways. Part two gives an example MDACT regimen, gMDACT, which uses six repurposed drugs-celecoxib, dapsone, disulfiram, itraconazole, pyrimethamine, and telmisartan-to interfere with growth-driving elements common to cholangiocarcinoma, colon adenocarcinoma, glioblastoma, and non-small-cell lung cancer. gMDACT is another example of-not a replacement for-previous multidrug regimens already in clinical use, such as CUSP9v3. MDACT regimens are designed as adjuvants to be used with cytotoxic drugs.

[Research Progress in Immunosuppressive Tumor Microenvironment of Gastrointestinal Cancer]

Gastrointestinal (GI) cancer, a common malignant tumor with a high incidence in China, is showing a trend of rising incidence and is afflicting increasingly younger patients. Meanwhile, there have been constant development and innovations in new therapeutic technologies, among which, immunotherapy is now leading in a new era in the treatment of GI cancer. However, the complexity and diversity of immunosuppressive tumor microenvironment (TME) bring many obstacles to the immunotherapy of solid tumors in the GI tract. In this paper, focusing on solid tumors in the GI tract, we reviewed the main factors affecting the formation of immunosuppressive TME, and summarized strategies for targeted immunosuppressive TME-based therapies. Moreover, we analyzed the synergistic mechanism of various combination immunotherapies and reported on the latest progress in and future direction of immunotherapy for GI cancer, intending to provide new perspectives for treating solid tumors in the GI tract with immumotherapy.

The Role of the Renin-Angiotensin System in the Cancer Stem Cell Niche

Cancer stem cells (CSCs) drive metastasis, treatment resistance, and tumor recurrence. CSCs reside within a niche, an anatomically distinct site within the tumor microenvironment (TME) that consists of malignant and non-malignant cells, including immune cells. The renin-angiotensin system (RAS), a critical regulator of stem cells and key developmental processes, plays a vital role in the TME. Non-malignant cells within the CSC niche and stem cell signaling pathways such as the Wnt, Hedgehog, and Notch pathways influence CSCs. Components of the RAS and cathepsins B and D that constitute bypass loops of the RAS are expressed on CSCs in many cancer types. There is extensive in vitro and in vivo evidence showing that RAS inhibition reduces tumor growth, cell proliferation, invasion, and metastasis. However, there is inconsistent epidemiological data on the effect of RAS inhibitors on cancer incidence and survival outcomes, attributed to different patient characteristics and methodologies used between studies. Further mechanistic studies are warranted to investigate the precise effects of the RAS on CSCs directly and/or the CSC niche. Targeting the RAS, its bypass loops, and convergent signaling pathways participating in the TME and other key stem cell pathways that regulate CSCs may be a novel approach to cancer treatment.

Roles of G Protein-Coupled Receptors (GPCRs) in Gastrointestinal Cancers: Focus on Sphingosine 1-Shosphate Receptors, Angiotensin II Receptors, and Estrogen-Related GPCRs

It is well established that gastrointestinal (GI) cancers are common and devastating diseases around the world. Despite the significant progress that has been made in the treatment of GI cancers, the mortality rates remain high, indicating a real need to explore the complex pathogenesis and develop more effective therapeutics for GI cancers. G protein-coupled receptors (GPCRs) are critical signaling molecules involved in various biological processes including cell growth, proliferation, and death, as well as immune responses and inflammation regulation. Substantial evidence has demonstrated crucial roles of GPCRs in the development of GI cancers, which provided an impetus for further research regarding the pathophysiological mechanisms and drug discovery of GI cancers. In this review, we mainly discuss the roles of sphingosine 1-phosphate receptors (S1PRs), angiotensin II receptors, estrogen-related GPCRs, and some other important GPCRs in the development of colorectal, gastric, and esophageal cancer, and explore the potential of GPCRs as therapeutic targets.

Comprehensive landscape of the renin-angiotensin system in Pan-cancer: a potential downstream mediated mechanism of SARS-CoV-2

Background: SARS-CoV-2, the cause of the worldwide COVID-19 pandemic, utilizes the mechanism of binding to ACE2 (a crucial component of the renin-angiotensin system [RAS]), subsequently mediating a secondary imbalance of the RAS family and leading to severe injury to the host. However, very few studies have been conducted to reveal the mechanism behind the effect of SARS-CoV-2 on tumors.

Methods: Demographic data extracted from 33 cancer types and over 10,000 samples were employed to determine the comprehensive landscape of the RAS. Expression distribution, pretranscriptional and posttranscriptional regulation and posttranslational modifications (PTMs) as well as genomic alterations, DNA methylation and m6A modification were analyzed in both tissue and cell lines. The clinical phenotype, prognostic value and significance of the RAS during immune infiltration were identified.

Results: Low expression of AGTR1 was common in tumors compared to normal tissues, while very low expression of AGTR2 and MAS1 was detected in both tissues and cell lines. Differential expression patterns of ACE in ovarian serous cystadenocarcinoma (OV) and kidney renal clear cell carcinoma (KIRC) were correlated with ubiquitin modification involving E3 ligases. Genomic alterations of the RAS family were infrequent across TCGA pan-cancer program, and ACE had the highest alteration frequency compared with other members. Low expression of AGTR1 may result from hypermethylation in the promoter. Downregulation of RAS family was linked to higher clinical stage and worse survival (as measured by disease-specific survival [DSS], overall survival [OS] or progression-free interval [PFI]), especially for ACE2 and AGTR1 in KIRC. ACE-AGTR1, a classical axis of the RAS family related to immune infiltration, was positively correlated with M2-type macrophages, cancer-associated fibroblasts (CAFs) and immune checkpoint genes in most cancers.

Conclusion: ACE, ACE2, AGT and AGTR1 were differentially expressed in 33 types of cancers. PTM of RAS family was found to rely on ubiquitination. ACE2 and AGTR1 might serve as independent prognostic factors for LGG and KIRC. SARS-CoV-2 might modify the tumor microenvironment by regulating the RAS family, thus affecting the biological processes of cancer.

Angiotensin II promotes primary tumor growth and metastasis formation of murine TNBC 4T1 cells through the fibroblasts around cancer cells

Angiotensin II (Ang II) reportedly facilitates primary tumor growth and distal hematogenous metastasis formation in various murine intravenous metastasis models. However, it is unclear whether Ang II accelerates the initial processes of metastasis formation that begins in primary tumors surrounded by tumor microenvironment. We examined the effects of Ang II on primary tumors and lung metastasis lesions using a murine spontaneous metastasis model, in which triple negative breast cancer 4T1 cells constitutively expressing luciferase (4T1-Luc cells) were injected into the mammary fat pad of BALB/c mice. Subcutaneous injection of Ang II significantly accelerated primary tumor growth and lung metastasis formation. Ang II increased the protein expression levels of c-Myc, cyclin D1, fibronectin, vimentin, αSMA and Snail, and the treatment with the Ang II type 1 receptor blocker valsartan significantly suppressed the Ang II-induced increases of fibronectin and vimentin. Valsartan also significantly reduced lung metastatic lesions. However, Ang II did not have significant effects on 4T1-Luc cells including the proliferation, migration, invasion, or the expressions of proteins related to cell proliferation and epithelial-to-mesenchymal transition. In contrast, when 4T1-Luc cells were co-cultured with dermal fibroblasts, Ang II significantly accelerated cell migration and increased the expressions of fibronectin, vimentin, αSMA and Snail in 4T1-Luc cells. And moreover, Ang II significantly increased the mRNA expression of IL-6 in fibroblasts co-cultured with 4T1-Luc cells. These results suggested that Ang II accelerates surrounding fibroblasts by soluble factors such as IL-6 to promote epithelial-to-mesenchymal transition, which result in the initiation of cancer metastasis.

Effect of concomitant use of antihypertensives and immune check point inhibitors on cancer outcomes

OBJECTIVES

Antihypertensives and cancer have a complex relationship. Among the antihypertensives, renin--angiotensin system inhibitors have strong immune modulatory activities that may affect immune check point inhibitors-related outcomes in cancer patients. We evaluated the association between concomitant use of renin--angiotensin system inhibitors and other antihypertensive agents with survival/toxicity outcomes from atezolizumab.

METHODS

A post hoc analysis of individual patient data from seven clinical trials of lung, renal or urothelial cancers was performed. Users and nonusers of antihypertensive classes were compared for overall survival, progression-free survival and immune adverse events. Cox proportional hazards were calculated between the groups and reported as hazards ratio and 95% confidence interval (95% CI).

RESULTS

Of the 3695 patients, 2539 were treated with atezolizumab and the rest with chemotherapy. Twenty-four percent of patients were on a renin--angiotensin system inhibitor at trial commencement. No statistically significant difference in overall survival (hazard ratio 0.92, 95% CI 0.79-1.07, P = 0.29), progression-free survival (hazard ratio 0.95, 95% CI 0.84-1.08, P = 0.42) or immune adverse events (odds ratio 0.94, 95% CI 0.76-1.15, P = 0.55) between renin--angiotensin system inhibitor users and nonusers were identified in the atezolizumab-treated cohort. Other classes of antihypertensives were also not associated with survival.

CONCLUSION

Concomitant use of antihypertensives including RASi was not associated with survival and immune-related safety outcomes during atezolizumab therapy for solid cancers. Future studies should evaluate the association between antihypertensives and other ICI as well as ICI combination interventions in clinical trials and real-world settings.

Immunomodulatory effects of renin-angiotensin system inhibitors on T lymphocytes in mice with colorectal liver metastases

Background

It is now recognized that many anticancer treatments positively modulate the antitumor immune response. Clinical and experimental studies have shown that inhibitors of the classical renin–angiotensin system (RAS) reduce tumor progression and are associated with better outcomes in patients with colorectal cancer. RAS components are expressed by most immune cells and adult hematopoietic cells, thus are potential targets for modulating tumor-infiltrating immune cells and can provide a mechanism of tumor control by the renin–angiotensin system inhibitors (RASi).

Aim

To investigate the effects of the RASi captopril on tumor T lymphocyte distribution in a mouse model of colorectal liver metastases.

Methods

Liver metastases were established in a mouse model using an autologous colorectal cancer cell line. RASi (captopril 750 mg/kg) or carrier (saline) was administered to the mice daily via intraperitoneal injection, from day 1 post-tumor induction to endpoint (day 15 or 21 post-tumor induction). At the endpoint, tumor growth was determined, and lymphocyte infiltration and composition in the tumor and liver tissues were analyzed by flow cytometry and immunohistochemistry (IHC).

Results

Captopril significantly decreased tumor viability and impaired metastatic growth. Analysis of infiltrating T cells into liver parenchyma and tumor tissues by IHC and flow cytometry showed that captopril significantly increased the infiltration of CD3⁺ T cells into both tissues at day 15 following tumor induction. Phenotypical analysis of CD45⁺ CD3⁺ T cells indicated that the major contributing phenotype to this influx is a CD4 and CD8 double-negative T cell (DNT) subtype, while CD4⁺ T cells decreased and CD8⁺ T cells remained unchanged. Captopril treatment also increased the expression of checkpoint receptor PD-1 on CD8⁺and DNT subsets.

Conclusion

Captopril treatment modulates the immune response by increasing the infiltration and altering the phenotypical composition of T lymphocytes and may be a contributing mechanism for tumor control.

Further Understanding of the Immune Microenvironment in Head and Neck Squamous Cell Carcinoma: Implications for Prognosis

Purpose

We aimed to review the literature on the tumor microenvironment as a key player in tumor growth and anti-cancer treatment responses in head and neck cancer.

Patients and Methods

We reviewed the recent literature on this topic, using the following research words: “tumor microenvironment” and “head and neck cancer or neoplasm or head and neck squamous cell carcinoma” and “immune cells” and “stromal cells”. A search was conducted on the PubMed website and reports from international meetings, presentations and abstracts.

Results

The tumor microenvironment is a complex network in which myeloid cells, tumoral cells, growth factors and cytokines are involved in angiogenesis, the extracellular matrix and epithelial-to-mesenchymal transition.

Conclusion

Immune resistance and rapid tumor growth depend on immunosuppressive and pro-tumoral environments. Further investigations to classify and adequately treat patients with head and neck cancer are required.

Breast cancer and the renin-angiotensin system (RAS): Therapeutic approaches and related metabolic diseases

The Renin-Angiotensin System (RAS) is classically recognized for regulating blood pressure and fluid balance. Recently, this role has extended to other areas including inflammation, obesity, diabetes, as well as breast cancer. RAS components are expressed in normal and cancerous breast tissues, and downregulation of RAS inhibits metastasis, proliferation, angiogenesis, and desmoplasia in the tumor microenvironment. Therefore, RAS inhibitors (Angiotensin receptor blockers, ARBs, or angiotensin converting enzyme inhibitors, ACE-I) may be beneficial as preventive adjuvant therapies to thwart breast cancer development and improve outcomes, respectively. Given the beneficial effects of RAS inhibitors in metabolic diseases, which often co-exist in breast cancer patients, combining RAS inhibitors with other breast cancer therapies may enhance the effectiveness of current treatments. This review scrutinizes above associations, to advance our understanding of the role of RAS in breast cancer and its potential for repurposing of RAS inhibitors to improve the therapeutic approach for breast cancer patients.

Impact of concomitant medication on clinical outcomes in patients with advanced non-small cell lung cancer treated with immune checkpoint inhibitors: A retrospective study

Background

It has recently been suggested that concomitant medication may affect the clinical outcome of patients treated with immune checkpoint inhibitors (ICIs). However, only a few studies on the impact of concomitant medication on immune‐related adverse events (irAEs) have previously been reported. Here, we aimed to determine the impact of concomitant medication on the efficacy and safety of ICIs.

Methods

We retrospectively analyzed the data of 300 patients treated with nivolumab or pembrolizumab for advanced non‐small cell lung cancer (NSCLC) between January 2016 and July 2018. Multivariate logistic regression analysis was used to assess the effect of concomitant medication on treatment response or irAEs. A multivariate Cox proportional hazards model was used to evaluate concomitant medication‐related factors associated with time‐to‐treatment failure or overall survival (OS).

Results

A total of 70 patients responded to treatment and 137 experienced irAEs. The response rate and incidence of irAEs in patients treated with ICIs were not significantly associated with concomitant medication. Multivariate analysis showed that the use of opioids was an independent factor (time‐to‐treatment failure: hazard ratio 1.39, p = 0.021, OS: hazard ratio 1.54, p = 0.007).

Conclusions

The efficacy and safety of nivolumab or pembrolizumab in the treatment of patients with advanced NSCLC were not significantly influenced by concomitant medication. However, opioid usage might be associated with shorter OS in patients treated with these ICIs. Further mechanistic investigations should explore whether these associations are purely prognostic or contribute to ICI resistance.

Angiotensin Receptor Blockers Are Not Just for Hypertension Anymore

Beyond blood pressure control, angiotensin receptor blockers reduce common injury mechanisms, decreasing excessive inflammation and protecting endothelial and mitochondrial function, insulin sensitivity, the coagulation cascade, immune responses, cerebrovascular flow, and cognition, properties useful to treat inflammatory, age-related, neurodegenerative, and metabolic disorders of many organs including brain and lung.

CCL5 production by fibroblasts through a local renin-angiotensin system in malignant melanoma affects tumor immune responses

PURPOSE

To enhance the antitumor effects of anti-programmed death-1 (PD-1) antibodies, it is important to reverse cancer-induced immunosuppression. We previously reported that a localized renin-angiotensin system in the tumor microenvironment inhibited tumor immunity via macrophages. In this study, we analyzed the underlying mechanism through which fibroblasts express tumor immunity influenced by the angiotensin receptor.

METHODS

We used an angiotensin receptor inhibitor (ARB) to inhibit renin-angiotensin system. Furthermore, angiotensin receptors were knocked out from mice fibroblasts, which were then collected. The fibroblasts and a malignant melanoma were then transfused into a mouse model and tumor immunity response was analyzed.

RESULTS

Fibroblasts produced CC motif chemokine ligand 5 (CCL5) on renin-angiotensin system stimulation, and this production decreased after ARB administration. In mice with transplanted malignant melanoma, ARB administration resulted in decreased CCL5 concentration in the blood, increase in tumor-infiltrating T cells, decrease in regulatory T cells, as well as an increase in tumor antigen-specific T-cell responses. The mice in which the angiotensin receptor knockout fibroblasts and malignant melanoma were transplanted showed a similar decrease in CCL5 concentration and increased tumor antigen-specific T-cell responses. Furthermore, ARB and anti-PD-1 antibody were administered in combination, which resulted in significantly better tumor growth inhibition over monotherapy.

CONCLUSION

Inhibiting renin-angiotensin system restored the therapeutic efficacy of inhibited anti-PD-1 antibodies. Thus, this could be considered a valid approach to enhance the therapeutic efficacy of anti-PD-1 antibodies.

The Tumor Proteolytic Landscape: A Challenging Frontier in Cancer Diagnosis and Therapy

In recent decades, dysregulation of proteases and atypical proteolysis have become increasingly recognized as important hallmarks of cancer, driving community-wide efforts to explore the proteolytic landscape of oncologic disease. With more than 100 proteases currently associated with different aspects of cancer development and progression, there is a clear impetus to harness their potential in the context of oncology. Advances in the protease field have yielded technologies enabling sensitive protease detection in various settings, paving the way towards diagnostic profiling of disease-related protease activity patterns. Methods including activity-based probes and substrates, antibodies, and various nanosystems that generate reporter signals, i.e., for PET or MRI, after interaction with the target protease have shown potential for clinical translation. Nevertheless, these technologies are costly, not easily multiplexed, and require advanced imaging technologies. While the current clinical applications of protease-responsive technologies in oncologic settings are still limited, emerging technologies and protease sensors are poised to enable comprehensive exploration of the tumor proteolytic landscape as a diagnostic and therapeutic frontier. This review aims to give an overview of the most relevant classes of proteases as indicators for tumor diagnosis, current approaches to detect and monitor their activity in vivo, and associated therapeutic applications.

Clinical applicability of renin-angiotensin system inhibitors in cancer treatment

The renin-angiotensin system (RAS) regulates physiological functions of the cardiovascular system, kidneys, and other tissues. Various in vivo and in vitro studies have shown that RAS plays a pivotal role in the development of malignant tumors, while several retrospective studies have confirmed that patients undergoing long-term RAS inhibitors (RASi) treatment have a lowered risk of cancer. Moreover, blocking RAS has been shown to inhibit tumor growth, metastasis, and angiogenesis in various experimental models of malignant tumors. Herein, we review the available RASi-related literature and provide an analysis using the scientific atlas software VOSviewer. We observed that recent studies have primarily focused on gene expression, tumor biology, and survival analysis. Through an in-depth data analysis from the Cancer Genome Atlas (TCGA) and Genotype Tissue Expression (GTEx), we identified the impact of AGTR1, an essential component of RAS, on tumors, and we discuss the underlying biological mechanism of RASi. Furthermore, we outline the research progress and potential use of RASi in tumor treatment. Overall, RASi may be a promising adjunct in cancer therapy.

Research Status and Molecular Mechanism of the Traditional Chinese Medicine and Antitumor Therapy Combined Strategy Based on Tumor Microenvironment

Treatment of malignant tumors encompasses multidisciplinary comprehensive diagnosis and treatment and reasonable combination and arrangement of multidisciplinary treatment, which is not a simple superimposition of multiple treatment methods, but a comprehensive consideration of the characteristics and specific conditions of the patients and the tumor. The mechanism of tumor elimination by restoring the body's immune ability is consistent with the concept of "nourishing positive accumulation and eliminating cancer by itself" in traditional Chinese medicine (TCM). The formation and dynamic changes in the tumor microenvironment (TME) involve many different types of cells and multiple signaling pathways. Those changes are similar to the multitarget and bidirectional regulation of immunity by TCM. Discussing the relationship and mutual influence of TCM and antitumor therapy on the TME is a current research hotspot. TCM has been applied in the treatment of more than 70% of cancer patients in China. Data have shown that TCM can significantly enhance the sensitivity to chemotherapeutic drugs, enhance tumor-suppressing effects, and significantly improve cancer-related fatigue, bone marrow suppression, and other adverse reactions. TCM treatments include the application of Chinese medicine monomers, extracts, classic traditional compound prescriptions, listed compound drugs, self-made compound prescriptions, as well as acupuncture and moxibustion. Studies have shown that the TCM functional mechanism related to the positive regulation of cytotoxic T cells, natural killer cells, dendritic cells, and interleukin-12, while negatively regulating of regulatory T cells, tumor-associated macrophages, myeloid-derived suppressive cells, PD-1/PD-L1, and other immune regulatory factors. However, the application of TCM in cancer therapy needs further study and confirmation. This article summarizes the existing research on the molecular mechanism of TCM regulation of the TME and provides a theoretical basis for further screening of the predominant population. Moreover, it predicts the effects of the combination of TCM and antitumor therapy and proposes further developments in clinical practice to optimize the combined strategy.

Renin-Angiotensin System in the Tumor Microenvironment

For enhancing the antitumor effects of current immunotherapies including immune-checkpoint blockade, it is important to reverse cancer-induced immunosuppression. The renin-angiotensin system (RAS) controls systemic body fluid circulation; however, the presence of a local RAS in tumors has been reported. Furthermore, the local RAS in tumors influences various immune and interstitial cells and affects tumor immune response. RAS stimulation through the angiotensin II type 1 receptor has been reported to inhibit tumor immune response. Therefore, RAS inhibitors and combined treatment with immunotherapy are expected in the future. In this chapter, we provide a background on the RAS and describe the tumor environment with regard to the RAS and tumor immune response.

The Effect of Local Renin Angiotensin System in the Common Types of Cancer

The Renin Angiotensin System (RAS) is a hormonal system that is responsible for blood pressure hemostasis and electrolyte balance. It is implicated in cancer hallmarks because it is expressed locally in almost all of the body's tissues. In this review, current knowledge on the effect of local RAS in the common types of cancer such as breast, lung, liver, prostate and skin cancer is summarised. The mechanisms by which RAS components could increase or decrease cancer activity are also discussed. In addition to the former, this review explores how the administration of AT1R blockers and ACE inhibitors drugs intervene with cancer therapy and contribute to the outcomes of cancer.

The Relationship Between Anti-Hypertensive Drugs and Cancer: Anxiety to be Resolved in Urgent

Hypertension is the prevailing independent risk factor for cardiovascular disease worldwide. Anti-hypertensive drugs are the common and effective cure for lowering blood pressure in patients with hypertension. However, some large-scale clinical studies have pointed out that long-term ingestion of some oral anti-hypertensive drugs was associated with risks of incident cancer and the survival time. In contrast, other studies argue that anti-hypertensive drugs are not related to the occurrence of cancer, even as a complementary therapy of tumor treatment. To resolve the dispute, numerous recent mechanistic studies using animal models have tried to find the causal link between cancer and different anti-hypertensive drugs. However, the results were often contradictory. Such uncertainties have taken a toll on hypertensive patients. In this review, we will summarize advances of longitudinal studies in the association between anti-hypertensive drugs and related tumor risks that have helped to move the field forward from associative to causative conclusions, in hope of providing a reference for more rigorous and evidence-based clinical research on the topic to guide the clinical decision making.

New tricks of old drugs: Repurposing non-chemo drugs and dietary phytochemicals as adjuvants in anti-tumor therapies

Combination therapy has long been applied to enhance therapeutic effect and deal with the occurrence of multi-drug resistance in cancer treatment. However, the overlapping toxicity of multiple anticancer drugs to healthy tissues and increasing financial burden on patients emerged as major concerns. As promising alternatives to chemo agents, repurposed non-chemo drugs and dietary phytochemicals have been investigated as adjuvants to conventional anti-tumor therapeutics, offering a safe and economic strategy for combination therapy. In this review, we aim to highlight the advances in research about combination therapy using conventional therapeutics and repurposed drugs or phytochemicals for an enhanced anti-tumor efficacy, along with the mechanisms involved in the synergism. Beyond these, we outlined the potential challenges and solutions for clinical translation of the proposed combination therapy, providing a safe and affordable strategy to improve the reach of cancer therapy to low income regions with such new tricks of old drugs.

Colon-specific immune microenvironment regulates cancer progression versus rejection

Immunotherapies have achieved clinical benefit in many types of cancer but remain limited to a subset of patients in colorectal cancer (CRC). Resistance to immunotherapy can be attributed in part to tissue-specific factors constraining antitumor immunity. Thus, a better understanding of how the colon microenvironment shapes the immune response to CRC is needed to identify mechanisms of resistance to immunotherapies and guide the development of novel therapeutics. In an orthotopic mouse model of MC38-CRC, tumor progression was monitored by bioluminescence imaging and the immune signatures were assessed at a transcriptional level using NanoString and at a cellular level by flow cytometry. Despite initial tumor growth in all mice, only 25% to 35% of mice developed a progressive lethal CRC while the remaining animals spontaneously rejected their solid tumor. No tumor rejection was observed in the absence of adaptive immunity, nor when MC38 cells were injected in non-orthotopic locations, subcutaneously or into the liver. We observed that progressive CRC tumors exhibited a protumor immune response, characterized by a regulatory T-lymphocyte pattern, discernible shortly post-tumor implantation, as well as suppressive myeloid cells. In contrast, tumor-rejecting mice presented an early inflammatory response and an antitumor microenvironment enriched in CD8⁺ T cells. Taken together, our data demonstrate the role of the colon microenvironment in regulating the balance between anti or protumor immune responses. While emphasizing the relevance of the CRC orthotopic model, they set the basis for exploring the impact of the identified signatures in colon cancer response to immunotherapy.

Intoxication With Endogenous Angiotensin II: A COVID-19 Hypothesis

Severe acute respiratory syndrome coronavirus 2 has spread rapidly around the globe. However, despite its high pathogenicity and transmissibility, the severity of the associated disease, COVID-19, varies widely. While the prognosis is favorable in most patients, critical illness, manifested by respiratory distress, thromboembolism, shock, and multi-organ failure, has been reported in about 5% of cases. Several studies have associated poor COVID-19 outcomes with the exhaustion of natural killer cells and cytotoxic T cells, lymphopenia, and elevated serum levels of D-dimer. In this article, we propose a common pathophysiological denominator for these negative prognostic markers, endogenous, angiotensin II toxicity. We hypothesize that, like in avian influenza, the outlook of COVID-19 is negatively correlated with the intracellular accumulation of angiotensin II promoted by the viral blockade of its degrading enzyme receptors. In this model, upregulated angiotensin II causes premature vascular senescence, leading to dysfunctional coagulation, and immunity. We further hypothesize that angiotensin II blockers and immune checkpoint inhibitors may be salutary for COVID-19 patients with critical illness by reversing both the clotting and immune defects (Graphical Abstract).

Renin-Angiotensin System in Lung Tumor and Microenvironment Interactions

The mechanistic involvement of the renin-angiotensin system (RAS) reaches beyond cardiovascular physiopathology. Recent knowledge pinpoints a pleiotropic role for this system, particularly in the lung, and mainly through locally regulated alternative molecules and secondary pathways. Angiotensin peptides play a role in cell proliferation, immunoinflammatory response, hypoxia and angiogenesis, which are critical biological processes in lung cancer. This manuscript reviews the literature supporting a role for the renin-angiotensin system in the lung tumor microenvironment and discusses whether blockade of this pathway in clinical settings may serve as an adjuvant therapy in lung cancer.

Angiotensin II contributes to intratumoral immunosuppressionvia induction of PD-L1 expression in non-small cell lung carcinoma

The formation of an immunosuppressive microenvironment and up-regulation of PD-L1 protein are the main causes of tumor immune escape. Previous reports suggest that Angiotensin II (Ang II) can modulate the immune status of tumor microenvironment in non-small cell lung cancer (NSCLC), but the underlying mechanism remains not fully understood. Here we demonstrated that AngII treatment causes the reduction of intratumoral infiltrating CD4 T lymphocytes in tumor-bearing mice, increases the accumulation of immunosuppressive granulocytes and TAMs in tumor tissue, and upregulates the expression levels of immunosuppressive marker genes. In addition, AngII/AGTR1 axis triggers cell PD-L1 expression through a mechanism involving increases in PD-L1 mRNA stability by human antigen R (HuR), an AU-rich element (ARE)-binding protein. Collectively, AngII/AGTR1 signaling promotes the tumor immunosuppressive microenvironment by upregulating PD-L1 in NSCLC, the mechanism of which is largely accounted by HuR-mediated PD-L1 mRNA stabilization.

GPC1 specific CAR-T cells eradicate established solid tumor without adverse effects and synergize with anti-PD-1 Ab

Current xenogeneic mouse models cannot evaluate on-target off-tumor adverse effect, hindering the development of chimeric antigen receptor (CAR) T cell therapies for solid tumors, due to limited human/mouse cross-reactivity of antibodies used in CAR and sever graft-versus-host disease induced by administered human T cells. We have evaluated safety and antitumor efficacy of CAR-T cells targeting glypican-1 (GPC1) overexpressed in various solid tumors. GPC1-specific human and murine CAR-T cells generated from our original anti-human/mouse GPC1 antibody showed strong antitumor effects in xenogeneic and syngeneic mouse models, respectively. Importantly, the murine CAR-T cells enhanced endogenous T cell responses against a non-GPC1 tumor antigen through the mechanism of antigen-spreading and showed synergistic antitumor effects with anti-PD-1 antibody without any adverse effects in syngeneic models. Our study shows the potential of GPC1 as a CAR-T cell target for solid tumors and the importance of syngeneic and xenogeneic models for evaluating their safety and efficacy.

Evaluating the benefits of renin-angiotensin system inhibitors as cancer treatments

G-protein-coupled receptors (GPCRs) are the largest and most diverse group of cellular membrane receptors identified and characterized. It is estimated that 30 to 50% of marketed drugs target these receptors. The angiotensin II receptor type 1 (AT1R) is a GPCR which signals in response to systemic alterations of the peptide hormone angiotensin II (AngII) in circulation. The enzyme responsible for converting AngI to AngII is the angiotensin-converting enzyme (ACE). Specific inhibitors for the AT1R (more commonly known as AT1R blockers or antagonists) and ACE are well characterized for their effects on the cardiovascular system. Combined with the extensive clinical data available on patient tolerance of AT1R blockers (ARBs) and ACE inhibitors (ACEIs), as well as their non-classical roles in cancer, the notion of repurposing this class of medications as cancer treatment(s) is explored in the current review. Given that AngII-dependent AT1R activity directly regulates angiogenesis, remodeling of vasculature, pro-inflammatory responses, stem cell programming and hematopoiesis, and electrolyte balance; the modulation of these processes with pharmacologically well characterized medications could present a valuable complementary treatment option for cancer patients.

A Prognostic Model Based on the Immune-related Genes in Colon Adenocarcinoma

Background: Immune-related genes (IRGs) are critically involved in the tumor microenvironment (TME) of colon adenocarcinoma (COAD). Here, the study was mainly designed to establish a prognostic model of IRGs to predict the survival of COAD patients. Methods: The Cancer Genome Atlas (TCGA), Immunology Database and Analysis Portal (ImmPort) database, and Cistrome database were utilized for extracting data regarding the expression of immune gene- and tumor-related transcription factors (TFs), aimed at the identification of differentially expressed genes (DEGs), differentially expressed IRGs (DEIRGs), and differentially expressed TFs (DETFs). Univariate Cox regression analysis was subsequently performed for the acquisition of prognosis-related IRGs, followed by establishment of TF regulatory network for uncovering the possible molecular regulatory association in COAD. Subsequently, multivariate Cox regression analysis was conducted to further determine the role of prognosis-related IRGs for prognostic prediction in COAD. Finally, the feasibility of a prognostic model with immunocytes was explored by immunocyte infiltration analysis. Results: A total of 2450 DEGs, 8 DETFs, and 79 DEIRGs were extracted from the corresponding databases. Univariate Cox regression analysis revealed 11 prognosis-related IRGs, followed by establishment of a regulatory network on prognosis-related IRGs at transcriptional levels. Functionally, IRG GLP2R was negatively modulated by TF MYH11, whereas IRG TDGF1 was positively modulated by TF TFAP2A. Multivariate Cox regression analysis was subsequently performed to establish a prognostic model on the basis of seven prognosis-related IRGs (GLP2R, ESM1, TDGF1, SLC10A2, INHBA, STC2, and CXCL1). Moreover, correlation analysis of immunocyte infiltration also revealed that the seven-IRG prognostic model was positively associated with five types of immunocytes (dendritic cell, macrophage, CD4 T cell, CD8 T cell, and neutrophil), which may directly reflect tumor immune state in COAD. Conclusions: Our present findings indicate that the prognostic model based on prognosis-related IRGs plays a crucial role in the clinical supervision and prognostic prediction of COAD patients at both molecular and cellular levels.

The Therapeutic Potential of Angiotensin-converting Enzyme and Angiotensin Receptor Inhibitors in the Treatment of Colorectal Cancer: Rational Strategies and Recent Progress

Colorectal cancer (CRC) is one of the most common causes of cancer-related death in the world. There is a document that angiotensin (AT) which is found to be involved in the progression of CRC. Furthermore, Angiotensin receptor inhibitors (ARIs) and angiotensin-converting enzyme Inhibitors (ACE-Is) demonstrate activity in CRC by their inhibition of both Insulin-like growth factor 1 (IGF-1) and Vascular endothelial growth factor (VEGF), and therefore present a potentially novel therapeutic strategy in colorectal cancer, which have summarized in the current review. Preclinical studies have illustrated the direct effect of major active mediator angiotensin II (ATII) on the promotion of angiogenesis through VEGF and other proliferative mediators. Suppression of the angiotensin II type I receptor (AT1R) via ACE-Is has shown a reduction in the development of solid tumor and metastasis, particularly CRC incidence, polyp formation, and distant metastasis. MicroRNAs (miRs) are a family of small nucleotides without coding that plays an important role after transcribing hundreds to thousands of non-coding and coding gene. Against this background, the application of anti-hypertensive medications such as losartan might have a therapeutic impact, although further preclinical and clinical studies might provide novel insight into the potentially beneficial effect of ACE-Is in the treatment of colorectal cancer patients.

Drug repurposing to overcome resistance to various therapies for colorectal cancer

Emergence of novel treatment modalities provides effective therapeutic options, apart from conventional cytotoxic chemotherapy, to fight against colorectal cancer. Unfortunately, drug resistance remains a huge challenge in clinics, leading to invariable occurrence of disease progression after treatment initiation. While novel drug development is unfavorable in terms of time frame and costs, drug repurposing is one of the promising strategies to combat resistance. This approach refers to the application of clinically available drugs to treat a different disease. With the well-established safety profile and optimal dosing of these approved drugs, their combination with current cancer therapy is suggested to provide an economical, safe and efficacious approach to overcome drug resistance and prolong patient survival. Here, we review both preclinical and clinical efficacy, as well as cellular mechanisms, of some extensively studied repurposed drugs, including non-steroidal anti-inflammatory drugs, statins, metformin, chloroquine, disulfiram, niclosamide, zoledronic acid and angiotensin receptor blockers. The three major treatment modalities in the management of colorectal cancer, namely classical cytotoxic chemotherapy, molecular targeted therapy and immunotherapy, are covered in this review.