Examination of the characteristics of long-term survivors among patients with gallbladder cancer with liver metastasis who underwent surgical treatment: a retrospective multicenter study (ACRoS1406)

DNMT3A Cooperates with YAP/TAZ to Drive Gallbladder Cancer Metastasis

Gallbladder cancer (GBC) is an extremely lethal malignancy with aggressive behaviors, including liver or distant metastasis; however, the underlying mechanisms driving the metastasis of GBC remain poorly understood. In this study, it is found that DNA methyltransferase DNMT3A is highly expressed in GBC tumor tissues compared to matched adjacent normal tissues. Clinicopathological analysis shows that DNMT3A is positively correlated with liver metastasis and poor overall survival outcomes in patients with GBC. Functional analysis confirms that DNMT3A promotes the metastasis of GBC cells in a manner dependent on its DNA methyltransferase activity. Mechanistically, DNMT3A interacts with and is recruited by YAP/TAZ to recognize and access the CpG island within the CDH1 promoter and generates hypermethylation of the CDH1 promoter, which leads to transcriptional silencing of CDH1 and accelerated epithelial-to-mesenchymal transition. Using tissue microarrays, the association between the expression of DNMT3A, YAP/TAZ, and CDH1 is confirmed, which affects the metastatic ability of GBC. These results reveal a novel mechanism through which DNMT3A recruitment by YAP/TAZ guides DNA methylation to drive GBC metastasis and provide insights into the treatment of GBC metastasis by targeting the functional connection between DNMT3A and YAP/TAZ.

Increased co-expression of PD1 and TIM3 is associated with poor prognosis and immune microenvironment heterogeneity in gallbladder cancer

BACKGROUND

The effectiveness of immune checkpoint inhibitors in treating gallbladder cancer (GBC) remains unsatisfactory. Recently, several new immune checkpoints have been identified. However, investigations exploring these immune checkpoints in GBC are limited. In this study, we aim to investigate the expression patterns and clinical implications of various immune checkpoints, and further characterize the spatial and quantitative heterogeneity of immune components in GBC.

METHODS

We employed single and multiplex immunohistochemistry to evaluate the expression of five immune checkpoint markers and four immune cell markers in the primary tumor core, hepatic invasion margin, and liver metastasis. Subsequently, we analyzed their interrelationships and their prognostic significance.

RESULTS

We observed a robust positive correlation between PD1/TIM3 expression in GBC (R = 0.614, P < 0.001). The co-expression of PD1/TIM3 exhibited a synergistic effect in predicting poor prognosis among postoperative GBC patients. Further analysis revealed that the prognostic significance of PD1/TIM3 was prominent in the subgroup with high infiltration of CD8 + T cells (P < 0.001). Multiplex immunohistochemistry reveals that PD1 + TIM3 + FOXP3 + cells constitute a significant proportion of FOXP3 + TILs in GBC tissue. Moreover, the co-high expression of PD1 and TIM3 is positively correlated with the accumulation of CD8 + TILs at the hepatic invasion margin. Lastly, our findings indicated reduced expression levels of immune checkpoints and diminished immune cell infiltration in liver metastases compared to primary tumors.

CONCLUSIONS

Increased co-expression of PD1/TIM3 is associated with poor prognosis in GBC patients and is related to the heterogeneity of immune microenvironment between GBC primary tumor and its hepatic invasion margin or liver metastases, which may be a potential target for future immunotherapy of GBC.

Successful conversion surgery for locally advanced gallbladder cancer after gemcitabine and nab-paclitaxel chemotherapy

Objective

Gallbladder cancer (GBC) is highly malignant and is often diagnosed at the advanced stage. Lack of opportunity to surgery results in an unsatisfactory outcome. This pilot study employed gemcitabine combined with nab-paclitaxel (AG) as a conversion therapeutic measure for locally advanced GBC and successfully achieved conversion surgery in three initially unresectable GBC patients. We will introduce our experience on improving the outcome of this dismal disease.

Methods

Radiology and nuclear medicine imaging were performed in each patient, and resectability was evaluated by joint consultation of our multi-disciplinary team (MDT). Patients evaluated as unresectable were treated with the AG regimen and re-evaluated for treatment response. When complete or partial response is achieved, MDT opinion would be required to assess the possibility of performing conversion surgery with R0 resection.

Results

Three GBC patients who were initially evaluated as unresectable successfully underwent R0 resection after conversion therapy with the AG regimen. The first case was a recurrent GBC patient evaluated as locally advanced and eventually achieved pathological complete response. The second case was a GBC patient who underwent R1 resection with residual lesions in the gallbladder bed and isolated No. 16 lymph node metastasis and who had a pathologically complete response after treatment. The third case had multiple but resectable liver metastases; both objective response and partial pathologic response were achieved. None of the patients experienced serious treatment-related adverse events. All cases revealed no evidence of recurrence or metastasis after a median follow-up of 12 months.

Conclusions

Conversion therapy shows a favorable efficacy in those unresectable GBC patients. Gemcitabine plus nab-paclitaxel has the potential to be used as a preoperative treatment option for GBC patients at the advanced stage. To further explore the efficacy of AG on conversion therapy for GBC patients, a prospective clinical trial has been registered (ChiCTR2200055698).