Intratumor tertiary lymphatic structure evaluation predicts the prognosis and immunotherapy response of patients with colorectal cancer.

Background: Immune checkpoint therapy, involving the programmed cell death 1 (PD-1) monoclonal antibody, has revolutionized the treatment of cancer. Tertiary lymphatic structure (TLS) serves as an immune indicator to predict the efficacy of PD-1 antibody therapy. However, there is no clear result whether the distribution, quantity, and maturity of TLS can be effective indicators for predicting the clinical efficacy of anti-PD1 immunotherapy in patients with colorectal cancer (CRC). Methods: Fifty-seven patients who underwent surgical resection and thirty-nine patients who received anti-PD-1 immunotherapy were enrolled in this retrospective study. Immunohistochemical staining and multiple fluorescence immunohistochemistry were used to evaluate the mismatch repair (MMR) subtypes and TLS distribution, quantity, and maturity, respectively. Results: A comprehensive patient score system was built based on TLS quantity and maturity. We found that the proportion of patients with score >1 was much higher in the deficient mismatch repair(dMMR) group than in the proficient mismatch repair(pMMR) group, and this difference was mainly due to intratumoral TLS. Patient score, based on the TLS evaluation of whole tumor, peritumor, or intratumor, was used to evaluate the efficacy of anti-PD1 immunotherapy. Based only on the intratumor TLS evaluation, the proportion of patients with a score >1 was higher in the response (PR + CR) group than in the non-response (PD) group. Multivariate analysis revealed that patient scores were positively correlated with the clinical efficacy of immunotherapy. Further analysis of immune-related progression-free survival was performed in patients with CRC who received anti-PD-1 immunotherapy. Patients with score >1 based on the intratumor TLS evaluation had significantly better survival. Conclusions: These results suggest that the patient score based on intratumor TLS evaluation may be a good immune predictive indicator for PD-1 antibody therapy in patients with CRC.

Dysregulated Th1 cells in lung squamous cell carcinoma.

Lung squamous cell carcinoma (LUSC) is a common subtype of lung cancer. Th1 cells contribute to antitumor immune responses. However, there are few studies on Th1 cells in LUSC. CD8+ T cells are the main driver of the antitumor immunity, targeting tumor cells killing. Th1 cells play an important auxiliary role in this process. Here, we used single-cell RNA-seq (scRNA-seq) to analyze qualified CD4+ T cells and Th1 cells (defined CD4+ T cells with 1 or more of STAT1+ , STAT4+ , T-bet+ , and IFN-γ+ as Th1 cells) from tissues of 8 LUSC patients. Then, we validated Th1 cells and CD8+ T cells of 32 LUSC patients by multiplex immunofluorescence staining and immunohistochemistry. Finally, we used flow cytometry to detect IFN-γ of CD4+ T cells in human PBMCs coincubated with LUSC-derived supernatant to simulate a tumor inhibitory microenvironment. ScRNA-seq showed IFN-γ+ Th1 cells account for 25.28% of all Th1 cells. Gene ontology and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analyses of differentially expressed genes between IFN-γ+ Th1 cells and IFN-γ- Th1 cells confirmed the decreased IFN-γ is associated with endoplasmic reticulum stress (ER stress). Multiplex immunofluorescence staining and immunohistochemistry proved there was a positive correlation between IFN-γ+ STAT1+ T-bet+ Th1 cells and CD8+ T cells. Flow cytometry showed IFN-γ secreted by Th1 cells is decreased. These findings support the claim that Th1 cells' function is suppressed in LUSC. Through scRNA-seq, we found that the decreased Th1 cells' function is associated with ER stress, which requires further study. Overall, these findings may produce a new method for the treatment of LUSC.

PGAM1 regulation of ASS1 contributes to the progression of breast cancer through the cAMP/AMPK/CEBPB pathway.

Phosphoglycerate mutase 1 (PGAM1) is a crucial glycolytic enzyme, and its expression status has been confirmed to be associated with tumor progression and metastasis. However, the precise role and other biological functions of PGAM1 remain unclear. Here, we report that PGAM1 expression is upregulated and related to poor prognosis in patients with breast cancer (BC). Functional experiments showed that knockdown of PGAM1 could suppress the proliferation, invasion, migration, and epithelial-mesenchymal transition of BC cells. Through RNA sequencing, we found that argininosuccinate synthase 1 (ASS1) expression was markedly upregulated in BC cells following PGAM1 knockdown, and it is required to suppress the malignant biological behavior of BC cells. Importantly, we demonstrated that PGAM1 negatively regulates ASS1 expression through the cAMP/AMPK/CEBPB axis. In vivo experiments further validated that PGAM1 promoted tumor growth in BC by altering ASS1 expression. Finally, immunohistochemical analysis showed that downregulated ASS1 levels were associated with PGAM1 expression and poor prognosis in patients with BC. Our study provides new insight into the regulatory mechanism of PGAM1-mediated BC progression that might shed new light on potential targets and combination therapeutic strategies for BC treatment.

CD4+ T cells are required to improve the efficacy of CIK therapy in non-small cell lung cancer.

As a widely studied adoptive treatment method, CIK (cytokine-induced killer cells) treatment has shown clinical benefits in many clinical trials on non-small cell lung cancer. As a heterogeneous cell population, however, CIK cells have a strong instability and individual differences in their efficacies, which are collaboratively regulated by the tumor microenvironment and CIK subpopulations. Among them, CD4+ T cells belong to a crucial subgroup of the CIK cell population, and their influence on CIK therapy is still unclear. Herein, we show how CD4+ T cells positively regulate the functions of CD3+CD56+ T and CD3+CD8+ T cells. During this process, we found that Th1/Th17 CD4+ subgroups can induce the phosphorylation of the AKT pathway by secreting IL-17A, and upregulate the expression of T-bet/Eomes transcription factors, thereby restoring the function of CD8+/CD3+CD56+ T cells and reversing the exhaustion of PD-1+Tim-3+ T cells. These findings will provide guidance for the clinical screening of suitable populations for CIK treatment and formulation of strategies for CIK therapy plus immune checkpoint treatment. Based on these findings, we are conducting an open-label phase II study (NCT04836728) is to evaluate the effects of autologous CIKs in combination with PD-1 inhibitor in the first-line treatment of IV NSCLC, and hope to observe patients' benefits in this clinical trial.

The Distinct Impact of TAM Infiltration on the Prognosis of Patients With Cardia and Non-Cardia Gastric Cancer and Its Association With H. pylori Infection.

BACKGROUND: In stage III gastric cancer (GC), the role of tumor-associated macrophages (TAMs) and Helicobacter pylori (H. pylori) infection impact tumor progression; however, the specific mechanisms remain controversial. We speculated whether this controversy is caused by differences in the location of TAM infiltration (in the core (CT) and invasive margin (MI) of primary tumors) and the topographical subsites of GC (cardia and non-cardia). Therefore, in this study, we investigated TAMs in different locations and H. pylori infection status as prognostic biomarkers for GC. METHODS: Immunohistochemical staining for CD68 (pan-macrophage), CD163 (M2-like macrophage), and H. pylori in 200 samples (100 cases of cardia-GC [CGC] and 100 cases of non-cardia GC [NCGC]) was performed. We compared the number of CD68+ and CD163+ macrophages that infiltrated the CT and MI in patients with the prognosis of CGC and NCGC, respectively. In addition, we analyzed the relationship between H. pylori status and the prognosis of patients with GC in different locations, as well as the correlation with TAM infiltration. RESULTS: The distribution of TAMs had distinct characteristics in CGC and NCGC, especially differences between CT and MI subtype. A Kaplan-Meier analysis showed that a high number of CD68+ macrophages that infiltrated the CT in CGC was associated with a better prognosis, whereas infiltration at the MI in NCGC indicated a poor prognosis. Furthermore, a high number of CD163+ macrophages infiltrating the MI resulted in a poor prognosis in CGC and NCGC cohorts. Considering the larger differences in the relationship between the infiltration of CD68+ macrophages at different locations and prognosis, we divided the GC cases into marginal and central GC, based on this difference. This resulted in an accurate estimation of the prognosis. Moreover, positive H. pylori status in central GC was significantly associated with a better prognosis and TAM infiltration. CONCLUSION: TAMs in different locations and H. pylori status were identified as independent prognostic markers, with an obvious correlation between them. Therefore, it is important to clarify the impact of TAM location on the prognosis of patients with GC, which contributes to the development of potential therapeutic strategies.

Insights into tertiary lymphoid structures in the solid tumor microenvironment: anti-tumor mechanism, functional regulation, and immunotherapeutic strategies.

Tertiary lymphoid structures (TLSs) are ectopic immune cell aggregations that develop in peripheral tissues in response to a wide range of chronic inflammatory conditions, including infection, autoimmune disease, and cancer. In the tumor microenvironment (TME), the structures of TLSs, including B-cell- and T-cell-enriched areas indicate that the TLSs might be the local site during the initiation and maintenance of humoral and cellular immune responses against cancers. Numerous studies have evaluated the expression of TLSs in different cancer patients and their association with prognoses of cancer patients. It was shown that well-developed TLSs characterized by mature B cells synthesized tumor specific antibodies, which were considered as specific markers for a good prognosis. However, there are still some immunosuppressive factors existing in the TLSs that may affect anti-tumor responses. These factors include dysfunctional B cells, regulatory T cells, and T follicular regulatory cells. The complexity and heterogeneity of the TLS composition may affect the function and activity of TLSs; it is therefore essential to fully understand the function and influencing factors in TLSs. It has been reported that checkpoint inhibitors and vaccines are currently being developed to reprogram the TME by establishing mature TLSs to improve cancer immunotherapies. In this review, we focused on recent advances in TLSs in human solid tumors, including structural characteristics and classes, antitumor mechanisms, immunosuppressive factors, and TLS-based therapeutic approaches.