Exploiting the obesity-associated immune microenvironment for cancer therapeutics

Host ANGPTL2 establishes an immunosuppressive tumor microenvironment and resistance to immune checkpoint therapy

Use of immune checkpoint inhibitors (ICIs) as cancer immunotherapy has advanced rapidly in the clinic; however, mechanisms underlying resistance to ICI therapy, including impaired T cell infiltration, low immunogenicity, and tumor "immunophenotypes" governed by the host, remain unclear. We previously reported that in some cancer contexts, tumor cell-derived angiopoietin-like protein 2 (ANGPTL2) has tumor-promoting functions. Here, we asked whether ANGPTL2 deficiency could enhance antitumor ICI activity in two inflammatory contexts: a murine syngeneic model of colorectal cancer and a mouse model of high-fat diet (HFD)-induced obesity. Systemic ANGPTL2 deficiency potentiated ICI efficacy in the syngeneic model, supporting an immunosuppressive role for host ANGPTL2. Relevant to the mechanism, we found that ANGPTL2 induces pro-inflammatory cytokine production in adipose tissues, driving generation of myeloid-derived suppressor cells (MDSCs) in bone marrow and contributing to an immunosuppressive tumor microenvironment and resistance to ICI therapy. Moreover, HFD-induced obese mice showed impaired responsiveness to ICI treatment, suggesting that obesity-induced chronic inflammation facilitated by high ANGPTL2 expression blocks ICI antitumor effects. Our findings overall provide novel insight into protumor ANGPTL2 functions and illustrate the essential role of the host system in ICI responsiveness.

Cancer treatments as paradoxical catalysts of tumor awakening in the lung

Much of the fatality of tumors is linked to the growth of metastases, which can emerge months to years after apparently successful treatment of primary tumors. Metastases arise from disseminated tumor cells (DTCs), which disperse through the body in a dormant state to seed distant sites. While some DTCs lodge in pre-metastatic niches (PMNs) and rapidly develop into metastases, other DTCs settle in distinct microenvironments that maintain them in a dormant state. Subsequent awakening, induced by changes in the microenvironment of the DTC, causes outgrowth of metastases. Hence, there has been extensive investigation of the factors causing survival and subsequent awakening of DTCs, with the goal of disrupting these processes to decrease cancer lethality. We here provide a detailed overview of recent developments in understanding of the factors controlling dormancy and awakening in the lung, a common site of metastasis for many solid tumors. These factors include dynamic interactions between DTCs and diverse epithelial, mesenchymal, and immune cell populations resident in the lung. Paradoxically, among key triggers for metastatic outgrowth, lung tissue remodeling arising from damage induced by the treatment of primary tumors play a significant role. In addition, growing evidence emphasizes roles for inflammation and aging in opposing the factors that maintain dormancy. Finally, we discuss strategies being developed or employed to reduce the risk of metastatic recurrence.

A multidimensional analysis of the impact of obesity on immune checkpoint inhibitor therapy efficacy

BACKGROUND

Obesity is a well-known risk factor for developing malignant tumors and promoting tumor cell growth and spread. However, recent studies have shown that obese cancer patients, who typically have a worse prognosis than nonobese cancer patients, show a significant improvement in survival after receiving immune checkpoint inhibitor (ICI) therapy. This phenomenon is known as the "obesity paradox". However, this phenomenon is influenced by tumor type and sex. Therefore, this study aimed to explore the impact of obesity on immunotherapy efficacy from multiple perspectives, aiming to verify this paradox and provide new scientific evidence on the effect of obesity on ICI efficacy.

METHODS

This retrospective study evaluated the data of patients who received ICI therapy between June 2019 and August 2023. Automatic segmentation of skeletal muscle, subcutaneous fat, and visceral fat was performed using Slice-O-Matic software, and the corresponding skeletal muscle index (SMI), subcutaneous fat index (SFI) and visceral fat index (VFI) were calculated. The neutrophil-to-lymphocyte ratio (NLR) was determined by dividing the neutrophil count by the lymphocyte count. Univariate and multivariate Cox regression analyses were used to evaluate the correlation between body mass index (BMI), body composition parameters, and the NLR with overall survival (OS) and progression-free survival (PFS) in obese patients receiving ICI therapy.

RESULTS

We analyzed 219 patients with a median age of 60 years (IQR 53-69 years; 155 men and 64 women). Obese patients, particularly those with visceral fat accumulation, exhibited extended OS after ICI therapy (log-rank P = 0.027). Cox multivariate analysis revealed that the NLR (HR = 1.036; 95% CI: 0.996 to 1.078; P = 0.002) was independently associated with OS. Patients with a high NLR had worse OS than those with a low NLR.

CONCLUSIONS

This study corroborates the veracity of the "obesity paradox" under specific conditions and identifies NLR as an independent prognostic factor, with elevated NLR indicative of a poor prognosis.

Obesity, dysbiosis and inflammation: interactions that modulate the efficacy of immunotherapy

Recent years have seen an outstanding growth in the understanding of connections between diet-induced obesity, dysbiosis and alterations in the tumor microenvironment. Now we appreciate that gut dysbiosis can exert important effects in distant target tissues via specific microbes and metabolites. Multiple studies have examined how diet-induced obese state is associated with gut dysbiosis and how gut microbes direct various physiological processes that help maintain obese state in a bidirectional crosstalk. Another tightly linked factor is sustained low grade inflammation in tumor microenvironment that is modulated by both obese state and dysbiosis, and influences tumor growth as well as response to immunotherapy. Our review brings together these important aspects and explores their connections. In this review, we discuss how obese state modulates various components of the breast tumor microenvironment and gut microbiota to achieve sustained low-grade inflammation. We explore the crosstalk between different components of tumor microenvironment and microbes, and how they might modulate the response to immunotherapy. Discussing studies from multiple tumor types, we delve to find common microbial characteristics that may positively or negatively influence immunotherapy efficacy in breast cancer and may guide future studies.

The Complex Connection between Obesity and Cancer: Signaling Pathways and Therapeutic Implications

Obesity has emerged as an important global health challenge, significantly influencing the incidence and progression of various cancers. This comprehensive review elucidates the complex relationship between obesity and oncogenesis, focusing particularly on the role of dysregulated signaling pathways as central mediators of this association. We delve into the contributions of obesity-induced alterations in key signaling cascades, including PI3K/AKT/mTOR, JAK/STAT, NF-κB, and Wnt/β-catenin to carcinogenesis. These alterations facilitate unchecked cellular proliferation, chronic inflammation and apoptosis resistance. Epidemiological evidence links obesity with increased cancer susceptibility and adverse prognostic outcomes, with pronounced risks for specific cancers such as breast, colorectal, endometrial and hepatic malignancies. This review synthesizes data from both animal and clinical studies to underscore the pivotal role of disrupted signaling pathways in shaping innovative therapeutic strategies. We highlight the critical importance of lifestyle modifications in obesity management and cancer risk mitigation, stressing the benefits of dietary changes, physical activity, and behavioral interventions. Moreover, we examine targeted pharmacological strategies addressing aberrant pathways in obesity-related tumors and discuss the integration of cutting-edge treatments, including immunotherapy and precision medicine, into clinical practice.

Effect of body mass index and cholesterol-rich apolipoprotein-B-containing lipoproteins on clinical outcome in NSCLC patients treated with immune checkpoint inhibitors-based therapy: A retrospective analysis

OBJECTIVES

Obesity and hypercholesterolemia are linked to unfavor clinical outcomes. Recent studies declared the paradox that high body mass index (BMI) and serum cholesterol were independently connected to better clinical outcome of immune checkpoint inhibitors (ICIs) monotherapy in non-small cell lung cancer (NSCLC). The aim of the study is to investigate the prognosis of BMI and serum cholesterol in ICIs-based therapy.

METHODS

This is a retrospective study of 95 NSCLC patients treated with ICIs-based therapy at the Department of Oncology and Lung Cancer Center of China-Japan Friendship Hospital. Treatment efficacy was assessed using durable clinical benefit (DCB) versus nondurable benefit (NDB), best response (active vs. nonactive), and progression-free survival (PFS). The prognostic value of BMI, LDL-C, and RC was determined by multivariate regression analyses, while controlling for confounding factors including age, gender, diabetes status, smoking history, and statin usage. BMI was considered a confounding factor in the analysis when examining the impact of lipoproteins.

RESULTS

In our study, we found that in the whole group, BMI ≥25 kg/m2 was linked to a higher risk of poor therapeutic response (OR = 5.92, 95% CI 1.99-19.51, p.val = 0.002) and shorter progression-free survival (HR = 3.00, 95% CI 1.59-5.68, p.val = 0.001). In addition, low levels of RC were associated with better therapeutic response (OR = 0.12, 95% CI 0.02-0.64, p.val = 0.019), while low levels of serum LDL-C were found to predict longer PFS (HR = 0.40, 95% CI 0.19-0.82, p.val = 0.012). These associations were consistent in advanced NSCLC patients receiving ICIs and chemotherapy.

CONCLUSIONS

Our study suggest that BMI ≥25 kg/m2 and elevated levels of apoB-containing lipoproteins, including LDL-C and RC, could potentially serve as useful prognostic markers for predicting poor treatment outcomes in advanced NSCLC patients treated with the combination of chemotherapy and ICIs.

Obesity enhances the response to neoadjuvant anti-PD1 therapy in oral tongue squamous cell carcinoma

OBJECTIVES

Previous studies have demonstrated that obesity may impact the efficacy of anti-PD1 therapy, but the underlying mechanism remains unclear. In this study, our objective was to determine the prognostic value of obesity in patients with oral tongue squamous cell carcinoma (OTSCC) treated with pembrolizumab and establish a subtype based on fatty acid metabolism-related genes (FAMRGs) for immunotherapy.

MATERIALS AND METHODS

We enrolled a total of 56 patients with OTSCC who underwent neoadjuvant anti-PD1 therapy. Univariate and multivariate Cox regression analyses, Kaplan-Meier survival analysis, and immunohistochemistry staining were performed. Additionally, we acquired the gene expression profiles of pan-cancer samples and conducted GSEA and KEGG pathway analysis. Moreover, data from TCGA, MSigDB, UALCAN, GEPIA and TIMER were utilized to construct the FAMRGs subtype.

RESULTS

Our findings indicate that high Body Mass Index (BMI) was significantly associated with improved PFS (HR = 0.015; 95% CI, 0.001 to 0.477; p = 0.015), potentially attributed to increased infiltration of PD1 + T cells. A total of 91 differentially expressed FAMRGs were identified between the response and non-response groups in pan-cancer patients treated with immunotherapy. Of these, 6 hub FAMRGs (ACSL5, PLA2G2D, PROCA1, IL4I1, UBE2L6 and PSME1) were found to affect PD-1 expression and T cell infiltration in HNSCC, which may impact the efficacy of anti-PD1 therapy.

CONCLUSION

This study demonstrates that obesity serves as a robust prognostic predictor for patients with OTSCC undergoing neoadjuvant anti-PD1 therapy. Furthermore, the expression of 6 hub FAMRGs (ACSL5, PLA2G2D, PROCA1, IL4I1, UBE2L6 and PSME1) plays a pivotal role in the context of anti-PD1 therapy and deserves further investigation.

Transcatheter arterial chemoembolisation combined with lenvatinib and cabozantinib in the treatment of advanced hepatocellular carcinoma

OBJECTIVE

The objective of this study was to evaluate the effect and prognosis of transcatheter arterial chemoembolisation (TACE) combined with lenvatinib and cabozantinib in the treatment of advanced unresectable hepatocellular carcinoma (uHCC) and identify the predictors of prognosis related to cellular inflammation and body mass index (BMI). To the best of our knowledge, this is the first study to report the efficacy and prognosis of TACE combined with lenvatinib and cabozantinib in patients with uHCC and propose the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) as predictors of response and survival outcomes in this context.

METHODS

The clinicopathologic data of 217 patients with advanced uHCC who underwent TACE combined with systemic therapy (lenvatinib mesylate + cabozantinib) in the Department of Hepatobiliary Surgery, Dazhou Central Hospital between October 2017 and February 2020 were collected retrospectively, and the relevant parameters were analysed and compared.

RESULTS

Univariate and multivariate logistic regression analyses showed that BMI, NLR, PLR and prothrombin time were independent factors for the objective response rate (ORR) of transformed therapy for uHCC (OR = 0.812 vs 1,290.68 vs 1.067 vs 0.626, 95 % CI: 0.719-0.897 vs 108.081-11,541.137 vs 1.037-1.099 vs 0.414-0.946, respectively, p < 0.05). The results showed that BMI, NLR and PLR had certain predictive values for the ORR in patients with liver cancer undergoing translational therapy (p < 0.05); the combined predictive effect of the three was the best, and the area under the curve (AUC) of BMI + NLR + PLR for predicting the ORR in patients with liver cancer undergoing translational therapy was 0.951 (95 % CI: 0.921, 0.964). A total of 181 patients experienced adverse reactions at different grades, including 104 cases at grade 1, 50 cases at grade 2, 22 cases at grade 3 and 5 cases at grade 4. There was a significant difference in overall survival (OS) between low- and high-NLR groups, low- and high-PLR groups and low- and high-BMI groups (χ2 = 9.644, 8.313 and 10.314, respectively, p < 0.05). There was a significant difference in progression-free survival (PFS) between the low- and high-NLR groups, the low- and high-PLR groups and the low- and high-BMI groups (χ2 = 8.965, 9.783 and 6.343, respectively, p < 0.05).

CONCLUSION

Transcatheter arterial chemoembolisation combined with lenvatinib and cabozantinib is safe and effective in the treatment of advanced uHCC, with controllable adverse reactions. High NLR and PLR and low BMI values before treatment were independent risk factors for the ORR. Body mass index, NLR and PLR predicted responses to triple switch therapy and survival outcomes in uHCC. Patients with pretreatment NLR ≥ 2.96 and PLR ≥ 184.41 had worse OS and PFS rates. Patients with pretreatment BMI ≥ 23 kg/m2 had improved OS and a reduced risk of death.

New Horizons: Epidemiology of Obesity, Diabetes Mellitus, and Cancer Prognosis

The global prevalence of obesity and diabetes mellitus has increased in parallel with increasing cancer incidence, due to environmental and lifestyle factors and population aging. Metabolic diseases are associated with increased cancer risk, so a growing number of patients with cancer have coexistent obesity and/or diabetes mellitus. In this narrative review, we highlight recent evidence on the clinical impact of obesity and diabetes mellitus on the prognosis of prostate, breast, and colorectal cancer, and provide an overview of the underlying mechanisms. There is evidence that obesity is associated with increased risk of recurrence, and all-cause and cancer-specific mortality among adults with prostate, breast, and colorectal cancer. Diabetes mellitus is associated with increased all-cause and cancer-specific mortality for these 3 cancers, beyond any impact of obesity. Evidence also suggests increased risk of colorectal cancer recurrence in patients with diabetes mellitus. The underlying mechanisms are multifactorial and likely include hormonal imbalances and chronic inflammation that promote cancer cell growth. Obesity and diabetes mellitus are associated with increased risk of complications and side effects of cancer treatment. Associated comorbidities such as impaired kidney function, cardiovascular disease, and neuropathies may preclude the use of guideline cancer treatment and are competing causes of death. Cancer patients with metabolic diseases require a designated clinical program and a multidisciplinary approach involving oncologists, endocrinologists, surgeons, nutritionists, and physiotherapists, to ensure coordinated and optimized patient care.

Depletion of Gr1+ myeloid cells attenuates high-fat-diet-aggravated esophageal squamous cell carcinoma in mice

Obesity is a leading cause of multiple cancers, but whether it promotes esophageal squamous cell carcinoma (ESCC) and its underlying cancer-promoting mechanism remains unclear. To evaluate the effect of a high-fat diet (HFD) on ESCC and explore the role and mechanism of myeloid-derived suppressor cells (MDSCs) in HFD-induced ESCC, C57BL/6J mice were treated with 4-nitroquinoline 1-oxide (4NQO) to induce ESCC and randomly assigned to an HFD or a normal-fat diet. An anti-Gr1 monoclonal antibody was used to deplete MDSCs in the context of experimental diets and ESCC induction. The expression of MDSC markers CD11b and Gr1 and immune checkpoints (ICs) PD1, TIM3, and VISTA in lesions were detected by immunohistochemistry. The correlation between myeloid cell markers (CD11b and CD33) and ICs and their relationship with ESCC patient prognosis were further analyzed using the The Cancer Genome Atlas dataset. The results showed that HFD accelerated esophageal carcinogenesis, induced MDSC expansion, and upregulated IC expression, whereas depletion of Gr1+ myeloid cells significantly suppressed tumor growth, decreased the number of MDSCs, and downregulated IC expression in HFD mice. PD1, TIM3, and VISTA expressions were positively correlated with myeloid cell marker expression in human ESCC. Moreover, the high expression of IC molecules was associated with poor survival in patients with ESCC. These data indicate that HFD promotes the initiation and development of ESCC. Gr1+ myeloid cell targeting significantly inhibited ESCC formation in HFD mice, which may be associated with IC downregulation.

The Canadian Society for Immunology's 34th annual meeting 2022: symposia minireview

The Canadian Society for Immunology 2022 Annual Meeting (June 17-20, 2022) brought together immunologists from across the country to discuss current topics and cutting-edge research in immunology. Here we highlight the published work presented during three thematic symposia (1) Immune Development and Layered Immunity; (2) Primary Immune Deficiencies from Thymic Developmental Defects to Dysregulation and Inflammation; and (3) Opposing Inflammatory and Suppressive Regulation of Anti-Tumor Immunity.

Lipid metabolism and tumor immunotherapy

In recent years, the relationship between lipid metabolism and tumour immunotherapy has been thoroughly investigated. An increasing number of studies have shown that abnormal gene expression and ectopic levels of metabolites related to fatty acid synthesis or fatty acid oxidation affect tumour metastasis, recurrence, and drug resistance. Tumour immunotherapy that aims to promote an antitumour immune response has greatly improved the outcomes for tumour patients. However, lipid metabolism reprogramming in tumour cells or tumour microenvironment-infiltrating immune cells can influence the antitumour response of immune cells and induce tumor cell immune evasion. The recent increase in the prevalence of obesity-related cancers has drawn attention to the fact that obesity increases fatty acid oxidation in cancer cells and suppresses the activation of immune cells, thereby weakening antitumour immunity. This article reviews the changes in lipid metabolism in cells in the tumour microenvironment and describes the relationship between lipid metabolism reprogramming in multiple cell types and tumour immunotherapy.

Survival and immunotoxicities in association with sex-specific body composition patterns of cancer patients undergoing immune-checkpoint inhibitor therapy - A systematic review and meta-analysis

BACKGROUND

Imbalanced body composition is mechanistically connected to dysregulated immune activities. Whether overweight/obesity or sarcopenia has an impact on treatment results in cancer patients undergoing immune checkpoint inhibitor (ICI) therapy is currently under debate. We aimed to answer if survival rates and occurrence of immune-related adverse events (irAEs) were different in obese or sarcopenic patients.

METHODS

A systematic search was conducted in PubMed, Embase and CENTRAL for all records published until July 2022 using specific search terms for body composition in combination with terms for ICI regimens. Two authors screened independently. All studies that reported on body mass index or sarcopenia measures were selected for further analysis.

RESULTS

48 studies reporting on overweight/obesity comprising of 19,767 patients, and 32 studies reporting on sarcopenia comprising of 3193 patients fulfilled the inclusion criteria. In the entire cohort, overweight/obesity was significantly associated with better progression-free survival (PFS; p = 0.009) and overall survival (OS; p <0.00001). Subgroup analyses stratified by sex revealed that overweight/obese males had the strongest survival benefit (PFS: p = 0.05; OS: p = 0.0005), and overweight/obese female patients did not show any. However, overweight/obese patients of both sexes had a higher risk to develop irAEs grade ≥3 (p = 0.0009). Sarcopenic patients showed significantly shorter PFS (p <0.0001) and OS (p <0.0001). The frequency of irAEs did not differ between sarcopenic and non-sarcopenic patients.

CONCLUSION

This meta-analysis suggests that body composition is associated in a sex-specific manner with survival and irAEs in cancer patients undergoing ICI treatment.

Tumor microenvironment and redox dual stimuli-responsive polymeric nanoparticles for the effective cisplatin-based cancer chemotherapy

The serious side effects of cisplatin hindered its clinical application and the nanotechnology might be the potential strategy to address the limitation. However, rapid clearance in the blood circulation and ineffective controlled drug release from nanocarriers hamper the therapeutic efficacy of the nano-delivery system. We constructed a tumor microenvironment and redox dual stimuli-responsive nano-delivery system PEG-c-(BPEI-SS-Pt) by cross-linking the disulfide-containing polymeric conjugate BPEI-SS-Pt with the dialdehyde group-modified PEG₂₀₀₀via Schiff base. After optimized the cross-linking time, 72 h was selected to get the nano-delivery system.¹H NMR and drug release assays showed that under the acidic tumor microenvironment (pH 6.5-6.8), the Schiff base can be broken and detached the PEG cross-linked outer shells, displaying the capability to release the drugs with a sequential pH- and redox-responsive manner. Moreover, PEG-c-(BPEI-SS-Pt) showed more effective anti-tumor therapeutic efficacyin vivowith no significant side effects when compared with the drug of cisplatin used in the clinic. This strategy highlights a promising platform with the dual stimuli-responsive profile to achieve better therapeutic efficacy and minor side effects for platinum-based chemotherapy.

Study of PD-1 Inhibitors in Combination with Chemoradiotherapy/Chemotherapy in Patients with Esophageal Squamous Carcinoma

In this study, we aimed to evaluate the efficacy of PD-1 inhibitors in combination with concurrent CRT/CT for patients with inoperable ESCC in the real world and to find predictors for the efficacy of PD-1 inhibitors. Patients with unresectable ESCC were evaluated at baseline. The clinical data of patients with ESCC who received CRT/CT with or without PD-1 inhibitor were collected and retrospectively reviewed. The objective response rate (ORR), overall survival (OS), and progression-free survival (PFS) were analyzed statistically. A total of 96 patients with ESCC were included. As compared with a control group (n = 48), the PFS (6.0 months vs. 5.0 months, p = 0.025) and 6-month OS (70.8% vs. 47.9%, p < 0.001) were significantly longer in the ICIs group (n = 48). There were no significant differences in ORR and 12-month OS between the two groups. In addition, we found that body mass index (BMI) was associated with PFS (HR 0.85, 95% CI 0.76−0.95, and p = 0.004) and OS (HR 0.82, 95% CI 0.69−0.98, and p = 0.033) in the ICIs group. PD-1 inhibitors combined with CRT/CT is safe with acceptable complications and improved survival for patients with inoperable ESCC. CRT plus PD-1 inhibitor has superior antitumor efficacy. BMI was positively correlated with the efficacy of PD-1 inhibitors.