Chemotherapeutic options for gastroesophageal junction tumors

ATAD2 interacts with C/EBPβ to promote esophageal squamous cell carcinoma metastasis via TGF-β1/Smad3 signaling

Background

Distant metastasis is the leading cause of death for esophageal squamous cell carcinoma (ESCC) with limited treatment options and unsatisfactory effectiveness. Bromodomain (BRD) containing proteins are emerging targets for cancer therapy with promising effects. As a unique member of BRD family, the function and molecular mechanism of ATAD2 in cancer development is seldomly investigated.

Methods

The clinical impact of ATAD2 was assessed both at RNA and protein level in 75 and 112 ESCC patients separately. The biological function of ATAD2 was investigated in vitro and in vivo. Signaling pathway and downstream effectors of ATAD2 were identified by RNA sequencing, luciferase reporter, co-immunoprecipitation, chromatin immunoprecipitation, immunofluorescence and western blot assay.

Results

We found that elevated ATAD2 expression was significantly associated with lymph node metastasis, advanced clinical stage as well as poor survival of ESCC patients. Silencing ATAD2 significantly suppressed ESCC cell migration and invasion in vitro, and inhibited tumor growth and lung metastasis in vivo. Mechanically, we identified a new cofactor, C/EBPβ. ATAD2 directly interacted with C/EBPβ and promoted its nuclear translocation, which directly bound to the promoter region of TGF-β1 and activated its expression. Further, we demonstrated that TGF-β1 activated its downstream effectors in a Smad3 dependent manner. In addition, we further found that ATAD2 promoted ESCC metastasis through TGF-β signaling induced Snail expression and the subsequent epithelial-mesenchymal transition.

Conclusion

Our findings demonstrated the pro-metastatic function of ATAD2 and uncovered the new molecular mechanism by regulating C/EBPβ/TGF-β1/Smad3/Snail signaling pathway, thus providing a potential target for the treatment of ESCC metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01905-x.

Treatment for unresectable or metastatic oesophageal cancer: current evidence and trends

Approximately half of the patients diagnosed with oesophageal cancer present with unresectable or metastatic disease. Treatment for these patients aims to control dysphagia and other cancer-related symptoms, improve quality of life and prolong survival. In the past 25 years, modestly improved outcomes have been achieved in the treatment of patients with inoperable non-metastatic cancer who are medically not fit for surgery or have unresectable, locally advanced disease. Concurrent chemoradiotherapy offers the best outcomes in these patients. In distant metastatic oesophageal cancer, several double-agent or triple-agent chemotherapy regimens have been established as first-line treatment options. In addition, long-term results of multiple large randomized phase III trials using additional targeted therapies have been published in the past few years, affecting contemporary clinical practice and future research directions. For the local treatment of malignant dysphagia, various treatment options have emerged, and self-expandable metal stent (SEMS) placement is currently the most widely applied method. Besides the continuous search for improved SEMS designs to minimize the risk of associated complications, efforts have been made to develop and evaluate the efficacy of antireflux stents and irradiation stents. This Review outlines the current evidence and ongoing trends in the different modern-day, multidisciplinary interventions for patients with unresectable or metastatic oesophageal cancer with an emphasis on key randomized trials.

Pre-treatment assay of 5-fluorouracil degradation rate (5-FUDR) to improve prediction of 5-fluorouracil toxicity in gastro-esophageal cancer

Background

5-fluorouracil (5-FU) based chemotherapy is the most common first line regimen used in gastric and gastroesophageal junction cancer, but development of severe toxicity is a main concern in the treatment. The present study is aimed to evaluate a novel pre-treatment assay, known as the 5-FU degradation rate (5-FUDR), as a predictive factor for 5-FU toxicity.

Methods

Pre-treatment 5-FUDR and gene polymorphisms related to 5-FU metabolism (DPYDIVS14+1G>A, MTHFRA1298T or C677T, TMYS TSER) were characterized in gastro-esophageal cancer patients. Association with toxicities was retrospectively evaluated, using multivariate logistic regression analysis.

Results

107 gastro-esophageal cancer patients were retrospectively analyzed. No relation between gene polymorphisms and toxicity were detected, while low (< 5^th centile) and high (> 95^th centile) 5-FUDRs were associated with development of grade 3-4 toxicity (OR 11.14, 95% CI 1.09-113.77 and OR 9.63, 95% CI 1.70-54.55, p = 0.002).

Conclusions

Compared to currently used genetic tests, the pre-treatment 5-FUDR seems useful in identifying patients at risk of developing toxicity.

Wide application of a novel topoisomerase I inhibitor-based drug conjugation technology

To establish a novel and widely applicable payload-linker technology for antibody-drug conjugates (ADCs), we have focused our research on applying exatecan mesylate (DX-8951f), a potent topoisomerase I inhibitor, which exhibits extensive antitumor activity as well as significant myelotoxicity, as the payload part. Through this study, we discovered a promising exatecan derivative (DX-8951 derivative, DXd), that has the characteristics of low membrane permeability and shows considerably less myelotoxicity than that shown by exatecan mesylate in an in vitro human colony forming unit-granulocyte macrophage assay. DXd was further used for drug conjugation by using commercially or clinically useful monoclonal antibodies to evaluate the potency of the ADC. The result revealed that the DXd-ADCs targeting CD30, CD33, and CD70 were effective against each of their respective target-expressing tumor cell lines. Moreover, a novel DXd-ADC targeting B7-H3, which is a new target for ADCs, also showed potent antitumor efficacy both in vitro and in vivo. In conclusion, this study showed that this novel topoisomerase I inhibitor-based ADC technology is widely applicable to a diverse number of antibodies and is expected to mitigate myelotoxicity, thereby possibly resulting in better safety profiles than that of existing ADC technologies.

p38δ MAPK phenotype: an indicator of chemotherapeutic response in oesophageal squamous cell carcinoma

We recently documented p38δ differential expression and function in oesophageal squamous cell carcinoma (OESCC). This study expands upon these findings and investigates whether p38δ status in OESCC can influence response(s) to cytotoxic drugs. The antiproliferative effect of conventional cisplatin and 5-fluorouracil (CF) treatment was compared with the recently reviewed triple regime of cisplatin, 5-fluorouracil and doxorubicin (ACF). p38δ-positive and p38δ-negative cell lines were employed using cell-growth and clonogenic assays. Key regulators of intrinsic and extrinsic apoptotic pathways were measured. Wound-healing assays and a Boyden chamber were used to investigate the effect of drug treatments on cell migration. Functional networks were analysed in terms of changes in MAPK expression. p38δ-negative OESCC is less sensitive to standard CF chemotherapy compared with p38δ-positive cells. However, following ACF treatment p38δ-negative cells showed markedly decreased proliferation and cell migration, and increased apoptosis. ACF induced apoptosis through the extrinsic pathway involving Fas activation, caspase-8 and caspase-3 cleavage and degradation of PARP. Loss of mitochondrial membrane potential (ΔΨm) was observed but downregulation of multidomain proapoptotic proteins, as well as BH3-only proteins, suggests involvement of pathways other than the mitochondrial pathway. Interestingly, induction of p38 and ERK1/2, but not JNK1/2, was observed following ACF treatment. p38δ-negative OESCC is more resistant to traditional CF treatment compared with p38δ-positive OESCC. In light of these results, p38δ phenotyping of tumour tissue may be of considerable value in deciding on an optimal therapeutic strategy for patients with p38δ-negative OESCC.

Role of stenting in the palliation of gastroesophageal junction cancer: A brief review

Gastroesophageal junction cancer has an increasing incidence in western countries. It is inoperable when first manifested in more than 50% of cases. So, palliation is the only therapeutic option for the advanced disease to relieve dysphagia and its consequences in weakened patients with an estimated mean survival under 6 mo. This article has tried to identify trends focusing on current information about the best palliative treatment, with an emphasis on the role of stenting. Self-expanding stent placement, either metal or plastic, is the main management option. However, this anatomical location creates some particular problems for stent safety and effectiveness which may be overcome by properly designed novel stents. The stents ensure a good quality of life and must be preferred over other alternative methods of loco-regional modalities, i.e., external radiation, laser thermal or photodynamic therapy. Although stent placement is generally a simple, safe and effective method, there are sometimes complications, increasing the morbidity and mortality rate. Bypass operative procedures have now been abandoned as a first choice. The stomach instead of the colon must be used for a bypass operation when it is needed. Chemotherapy, despite the toxicity, and intraluminal radiation (brachytherapy) have a well-defined role.

Clinical management of gastroesophageal junction tumors: past and recent evidences for the role of radiotherapy in the multidisciplinary approach

Gastroesophageal cancers (such as esophageal, gastric and gastroesophageal-junction -GEJ- lesions) are worldwide a leading cause of death being relatively rare but highly aggressive. In the past years, a clear shift in the location of upper gastrointestinal tract tumors has been recorded, both affecting the scientific research and the modern clinical practice. The integration of pre- or peri-operative multimodal approaches, as radiotherapy and chemotherapy (often combined), seems promising to further improve clinical outcome for such presentations. In the past, the definition of GEJ led to controversies and confusion: GEJ tumors have been managed either grouped to gastric or esophageal lesions, following slightly different surgical, radiotherapeutic and systemic approaches. Recently, the American Joint Committee on Cancer (AJCC) changed the staging and classification system of GEJ to harmonize some staging issues for esophageal and gastric cancer. This review discusses the most relevant historical and recent evidences of neoadjuvant treatment involving Radiotherapy for GEJ tumors, and describes the efficacy of such treatment in the frame of multimodal integrated therapies, from the new point of view of the recent classification of such tumors.