Oral Administration of Glucosylceramide Suppresses Tumor Growth by Affecting the Ceramide/Sphingosine-1-Phosphate Balance in Breast Cancer Tissue.

Background: Ceramide and sphingosine-1-phosphate (S1P) play opposing roles in cell death and survival, and maintain a dynamic balance called the sphingolipid rheostat. Glucosylceramide is a substrate to generate ceramide but its effect on breast cancer by oral administration was never tested. The purpose of this study was to reveal the anticancer activity of glucosylceramide and its potential as a new therapeutic agent in breast cancer. Methods: E0771 cells were inoculated into the breast tissue of female C57BL/6NJcl mice. Glucosylceramide was administered orally to the mice for nine consecutive days. The concentrations of sphingolipid mediators including ceramide, glucosylceramide, and S1P in tumor tissues and serum were determined by mass spectrometry. Results: Oral administration of glucosylceramide significantly suppressed E0771 tumor growth compared with the control group (P = 0.006). There were no significant differences in the serum concentrations of sphingolipid mediators including ceramide and S1P between the mice treated with glucosylceramide and control-treated mice. The ceramide concentration was significantly lower in tumor tissues (P = 0.026), and the S1P concentration was significantly higher than that in paired non-tumor tissues (P = 0.009). The S1P concentration in tumor tissues was significantly lower in mice treated with glucosylceramide than in control-treated mice (P = 0.001). The ceramide-to-S1P concentration ratio in tumor tissues was significantly higher in mice treated with glucosylceramide than in control-treated mice (P = 0.034). Conclusions: Breast tumors could enhance their survival by increasing S1P conversion from ceramide. Oral administration of glucosylceramide suppressed tumor growth by affecting the ceramide/S1P balance. Oral administration of glucosylceramide is a promising basis for a new therapeutic approach.

[A Case of Pancreatic Invasive Micropapillary Carcinoma That Survived Seven Years after Resection and Chemotherapy].

We present the case of a 47-year-old man who underwent a subtotal stomach-preserving pancreaticoduodenectomy for pancreatic head cancer. Histopathological diagnosis revealed that the majority of the cancer was an invasive micropapillary carcinoma(IMPC). Postoperative adjuvant chemotherapy using S-1 was continued for 4 years, at the end of which, multiple lymph node metastases were identified. Therefore, gemcitabine plus S-1 therapy was initiated. The treatment reduced the lymph node in size and resulted in the maintenance of a partial response for a year and a half. However, increased lymph node metastases recurred, and multiple lung metastases were noted. The patient died 7 years and 2 months after the resection of the primary lesion. Although pancreatic IMPC has a poor prognosis, long-term survival may be achieved by resection of the primary region, the administration of adjuvant chemotherapy and management of recurrent lesions by chemotherapy.

[A Case of Surgical Resection of Anaplastic Carcinoma of the Pancreas(Pleomorphic Cell Type)with Poor Response to Neoadjuvant Chemotherapy].

A 62-year-old man was incidentally found to have a pancreatic tumor by CT. He was diagnosed with pancreatic cancer by EUS-FNAB. Gemcitabine(GEM)plus nab-paclitaxel(PTX)was started as neoadjuvant chemotherapy(NAC)for resectable pancreatic cancer. However, after the end of the second course, the tumor grew rapidly and invaded the stomach, so NAC was discontinued, and surgery was performed. The pathological diagnosis was anaplastic ductal carcinoma of the pleomorphic cell type, and the histological response was Grade 1a. Multiple liver metastases appeared during adjuvant chemotherapy with S-1, so GEM plus nab-PTX and modified FOLFIRINOX were administered, but the therapeutic response was poor, the patient died 9 months after surgery. Anaplastic carcinoma has a poor response to chemotherapy and may be included with cancers showing treatment resistance to NAC, as seen in our case. It is necessary to pay attention to anaplastic carcinoma during the course of NAC for pancreatic cancer.