Identification of active components in Andrographis paniculata targeting on CD81 in esophageal cancer in vitro and in vivo

BACKGROUND

Esophageal cancer (EC) is highly prevalent in Eastern Asia (including China) with high rates of mortality. The metastatic tendency in EC is associated with a poor prognosis. Our previous studies have demonstrated the suppressive effects of Andrographis paniculata water extract (APW) on metastatic esophageal cancer in vitro and in tumor-bearing mice models, as well as illustrated the potential underlying mechanism by transcriptome analysis.

HYPOTHESIS

High expressions of several membrane protein tetraspanins were reported to lead to a high risk of metastasis in esophageal cancer in patients. We hypothesized that APW could downregulate the expression of tetraspanin CD81 in esophageal cancer cells and xenografts.

METHODS

Human esophageal cancer cells EC109 and KYSE520 were incubated with APW for 24 hours in cell culture, while mice bearing EC109 xenograft tumors were treated with APW for 21 days. The expressions of CD81 in cancer cells and in tumors from mice were evaluated. Molecular docking and microscale thermophoresis analyses were applied to identify the components in APW interacting with CD81. The influence of the identified components on CD81 expression was further evaluated in EC109 cells.

RESULTS

APW could significantly suppress the expressions of CD81 in both EC109 and KYSE520 cells in a concentration-dependent manner. Treatment of APW in xenograft-bearing mice reduces the metastasis in lungs, livers, and lymph nodes. The expression of CD81 in xenograft tumors of APW-treated mice was significantly lower than those of untreated control mice. The binding of andrographolide, bisandrographolide A, and bisandrographolide C with CD81 were elucidated by microscale thermophoresis. The suppressive effects of these compounds on the motility of EC109 cells, as well as CD81 protein and mRNA expressions, were further confirmed.

CONCLUSION

This is the first time to demonstrate that andrographolide, bisandrographolide A, and bisandrographolide C, which are present in APW, bind to CD81 and suppress its function. These compounds are likely to be responsible for the anti-metastatic activities of APW in esophageal cancer.

Multiple modulatory activities of Andrographis paniculata on immune responses and xenograft growth in esophageal cancer preclinical models

BACKGROUND

Esophageal cancer (EC) is a malignant gastrointestinal cancer with high morbidity worldwide and is the fourth leading cause of cancer-related deaths in China. Even though surgery and/or chemotherapy/chemoradiation might achieve good therapeutic response, recurrence rate is high due to cancer metastasis. Hence, the use of alternative adjuvant treatments, such as herbal medicines, for metastatic EC remains a great desire of the patients. Our previous studies have demonstrated the anti-metastatic efficacy of hot water extract of Andrographis paniculata (APW) in human esophageal cancer cells and tumor-bearing nude mice.

PURPOSE

In the present study, the immunomodulatory activities of APW were further evaluated in human peripheral blood mononuclear cells (PBMCs) and in a carcinogen-induced esophageal tumorigenesis model using immune-competent C57BL/6 mice. Besides, the inhibitory effects of APW on esophageal cancer cell line-based xenografts and patient-derived xenografts (PDX) were examined so as to illustrate the potential multi-targeted efficacies of APW in esophageal cancer in pre-clinical models.

RESULTS

In vitro results showed that APW could stimulate proliferation of PBMCs, as well as TNF-α and IFN-γproductions. In mice with 4-nitroquinoline 1-oxide-induced tumorigenesis, 21-day oral treatment with APW (1600 mg/kg) decreased the level of dysplasia in esophagus and significantly modulated the population of regulatory T cells. The cytokines productions by spleen lymphocytes of APW-treated mice were shifted towards normal resting state (i.e. unchallenged with carcinogen). Furthermore, APW treatment suppressed the growth of cell line-based xenografts by significantly increasing apoptosis in tumors, without causing severe body weight loss as chemotherapeutics did. Most importantly, the inhibitory effects of APW treatment on esophageal patient-derived xenografts growth were demonstrated for the first time. Besides, several diterpenes were detected in the plasma after oral administration of APW in mice, suggesting that multi-components of APW were bioavailable and might have contributed towards the varied pharmacological activities demonstrated in our studies.

CONCLUSION

APW was shown to possess anti-tumor, anti-metastatic and immunomodulatory activities in esophageal cancer cell-based and animal models, including immunocompromised mice model and clinically relevant PDX model. Our findings illustrated the potential multi-targeted efficacies of APW in esophageal cancer management.

Lymphovascular invasion as an independent prognostic indicator in radically resected thoracic esophageal squamous cell carcinoma

Background

The prognostic value of lymphovascular invasion (LVI) in esophageal cancer remains controversial. This study investigated the impact of LVI on prognosis in thoracic esophageal squamous cell carcinoma (ESCC).

Methods

A total of 1586 patients who underwent radical esophagectomy were selected for the study. Correlations between LVI and clinicopathological features were evaluated by χ² test. Univariate analysis of the survival curve was conducted using the Kaplan–Meier method. Multivariate analysis was carried out by Cox regression. The Akaike information criterion (AIC) and the concordance index (c‐index) were employed to assess model prognostic accuracy of different pN staging systems.

Results

The presence of LVI was detected in 406 of 1586 (25.6%) patients. LVI frequency was significantly higher in patients with higher pN classifications (P < 0.001). LVI had independent significant prognostic value in ESCC (P < 0.001). In subgroup analyses, the presence of LVI significantly decreased overall survival in pN0, pN2, and pN3 stage patients. The AIC value of the pN staging system modified by LVI was lower than that of the current pN staging system, while the c‐index of the modified pN staging system was higher than that of the current pN staging system.

Conclusion

Our results suggest that LVI is an independent prognostic indicator in radically resected thoracic ESCC. LVI could potentially supplement the pN ESCC staging system. ESCC patients with LVI could be staged at more advanced pN classifications.

A meta-analysis on salvage surgery as a potentially curative procedure in patients with isolated local recurrent or persistent esophageal cancer after chemoradiotherapy

BACKGROUND

Isolated local recurrent or persistent esophageal cancer (EC) after curative intended definitive (dCRT) or neoadjuvant chemoradiotherapy (nCRT) with initially omitted surgery, is a potential indication for salvage surgery. We aimed to evaluate safety and efficacy of salvage surgery in these patients.

MATERIAL AND METHODS

A systematic literature search following PRISMA guidelines was performed using databases of PubMed/Medline. All included studies were performed in patients with persistent or recurrent EC after initial treatment with dCRT or nCRT, between 2007 and 2017. Survival analysis was performed with an inverse-variance weighting method.

RESULTS

Of the 278 identified studies, 28 were eligible, including a total of 1076 patients. Postoperative complications after salvage esophagectomy were significantly more common among patients with isolated persistent than in those with locoregional recurrent EC, including respiratory (36.6% versus 22.7%; difference in proportion 10.9 with 95% confidence interval (CI) [3.1; 18.7]) and cardiovascular complications (10.4% versus 4.5%; difference in proportion 5.9 with 95% CI [1.5; 10.2]). The pooled estimated 30- and 90-day mortality was 2.6% [1.6; 3.6] and 8.0% [6.3; 9.8], respectively. The pooled estimated 3-year and 5-year overall survival (OS) were 39.0% (95% CI: [35.8; 42.2]) and 19.4% [95% CI:16.5; 22.4], respectively. Patients with isolated persistent or recurrent EC after initial CRT had similar 5-year OS (14.0% versus 19.7%, difference in proportion -5.7, 95% CI [-13.7; 2.3]).

CONCLUSIONS

Salvage surgery is a potentially curative procedure in patients with locally recurrent or persistent esophageal cancer and can be performed safely after definitive or neoadjuvant chemoradiotherapy when surgery was initially omitted.