Chie Takasu

Introduction: Lenvatinib is a multiple receptor tyrosine kinase inhibitor and a first‐line targeted therapy for hepatocellular carcinoma (HCC). However, its efficacy is insufficient because of acquired resistance. We investigated the role of exosomal miRNA exchange between resistant cancer cells and naive cancer cells in the development of lenvatinib resistance. Materials and Methods: We generated lenvatinib‐resistant (LVT‐res) Huh7 and PLC cell lines. We first analyzed the miRNA expression profiles of Nrf2 in cancer using three public datasets and then investigated exosomal miRNA expressions. Exosomal miRNA‐132 was found to be elevated in resistant cells compared with parental cells. The parental cells were cocultured with LVT‐res cultured conditioned medium as recipient cells. We then compared the characteristics in parental cancer cells, resistant cells, and recipient cells. Results: The proliferation and migration rates of recipient cells were significantly increased compared with the parental cells. Recipient cells also showed chemoresistance. The PTEN/GSK3β/Nrf2 signaling pathway was significantly upregulated in recipient cells compared with the parental cells. Inhibition of exosomal miRNA‐132 reduced the malignant potential of recipient cells, chemoresistance, cell proliferation, and migration rates. Furthermore, the PTEN/GSK3β/Nrf2 signaling pathway was downregulated in recipient cells with inhibition of exosomal miRNA‐132. Conclusion: Our study provides new findings on the role of the miRNA‐132/Nrf2 axis in LVT‐res cancer cells. This might be a potential therapeutic target in HCC chemoresistance.

Background: The concepts examined in tumor metabolism research have been moving away from cancer cells themselves and the tumor microenvironment has become a focus of investigation. Epigenetic changes affecting glucose metabolism in cancer‐associated fibroblasts (CAFs) in the tumor microenvironment regulate the malignancy of cancer cells. Light‐emitting diode (LED) have several functional effects, including anti‐tumor effects, through a variety of mechanisms. We previously reported that blue LED irradiation had an anti‐tumor effect via Opsin 3 that suppress CAF function in vivo and in vitro. However, the detailed mechanism by which LED affect CAF regulation remained unclear.Methods: CAFs were induced from human intestinal fibroblasts co‐cultured with colon cancer cells. Using lactate assays and reverse transcription‐quantitative PCR, the effects of LED irradiation on glycolysis in CAFs were investigated. The effects of LED irradiation for metabolic coupling were evaluated in vitro.Results: Reverse transcription‐quantitative PCR showed higher expression of CAF marker genes in induced CAFs. Blue LED irradiation of induced CAFs suppressed their ability to promote characteristics of tumor malignancy of colon cancer cell line. LED treatment decreased expression of glycolysis markers, including phosphofructokinase and monocarboxylate transporter 4, indicating inhibition of glycolytic activity in CAFs. Extracellular secretion of lactate from CAFs was decreased by LED irradiation.Conclusions: Blue LED irradiation targeted metabolic coupling between CAFs and colon cancer cells, thereby reducing the promotion of tumor progression by CAFs. Blue LED targeting glucose metabolism in CAFs is a promising anti‐cancer treatment option.

Background Colorectal cancer (CRC) has increasingly come into worldwide cancer and almost half of patients have liver metastasis (CRLM) during the progression. Therefore, treatment of colorectal cancer liver metastasis (CRLM) is important to improve the prognosis of CRC patients. Histopathological growth patterns (HGPs) of CRLM have emerged as a reliable prognostic marker. In this study, we investigated the role of prognostic impact of pure desmoplastic HGPs (dHGPs), 100% desmoplastic, in CRLM. Methods The present study evaluated the HGPs in 71 patients with CRLM who underwent surgery (R0) between 1995 and 2012. HGPs were classified by international consensus guidelines with H&E stained slides. The pure dHGPs was defined as a complete peripheral fibrotic rim around the tumor. Results The dHGP was present in 36.6% (n = 26) and the pure-dHGPs was present in 73% (n = 19) among dHGPs patients. Pure-dHGPs were significantly associated with sex (male), metachronous metastatic period, normal CEA level, shallow tumor invasion and less lymph node metastasis. Patients with dHGPs had longer overall survival (OS) compared to other HGPs (p < 0.05). Furthermore, pure dHGPs patients had longer OS than non-pure dHGPs (90.9% vs. 51.4%, p < 0.05). Multivariate analysis identified pure dHGPs (p = 0.04) and better primary tumor differentiation (p < 0.001) were identified as independent prognostic indicators for OS. Patients with pure dHGPs also had longer disease-free survival (DFS) compared to other HGPs (p < 0.05). Pure-dHGPs patients had longer DFS than non-pure dHGPs (63.4% vs. 28.8%, p < 0.05). Multivariate analysis identified pure dHGPs (p = 0.04) and better primary tumor differentiation (p = 0.03) as independent prognostic indicators. Conclusions Pure desmoplastic HGP might be a good prognostic marker in CRLM.

Laparoscopic gastrectomy (LG) requires a long learning curve because of the complicated surgical procedures. Infrapyloric (No. 6) lymph node dissection (LND) is one of the difficult procedures in LG, especially for trainees. This study investigated the impact of the prediction of the difficulty of No. 6 LND. We retrospectively reviewed the preoperative computed tomography (CT) images and individual operative video records of 57 patients who underwent LG with No. 6 LND to define and predict the No. 6 LND difficulty. To evaluate whether prediction of the difficulty of No. 6 LND could improve surgical outcomes, 48 patients who underwent laparoscopic distal gastrectomy were assessed (30 patients without prediction by a qualified surgeon and 18 patients with prediction by a trainee). The anatomical characteristic that LND required > 2 cm of dissection along the right gastroepiploic vein was defined as difficulty of No. 6 LND. Of the 57 LG patients, difficulty was identified intraoperatively in 21 patients (36.8%). Among the several evaluated anatomical parameters, the length between the right gastroepiploic vein and the right gastroepiploic artery in the maximum intensity projection in contrast-enhanced CT images was significantly correlated with the intraoperative difficulty of No. 6 LND (p < 0.0001). Surgical outcomes, namely intraoperative minor bleeding, postoperative pancreatic fistula, and drain amylase concentration were not significantly different between LG performed by a trainee with prediction compared with that by a specialist without prediction. Preoperative evaluation of the difficulty of No. 6 LND is useful for trainees, to improve surgical outcomes.

The outcomes of immune checkpoint blockade for colorectal cancer (CRC) treatment are unsatisfactory. Furthermore, the efficacy of immune checkpoint blockade for liver metastasis of various cancer is poor. Here, we investigated the relationship between stromal programmed death-ligand 1 (PD-L1) expression and the prognosis of patients with colorectal cancer liver metastasis (CRLM). The present study enrolled 84 CRLM patients who underwent surgery (R0) for CRC. Immunohistochemistry was performed to analyze stromal PD-L1 expression in CRLM. Stromal PD-L1 was expressed in 52.3% of CRLM samples, which was associated with fewer not optimally resectable metastases (p = 0.04). Stromal PD-L1 also tended to associate with a lower tumor grade (p = 0.08). Stromal PD-L1-positive patients had longer overall survival (p = 0.003). Multivariate analysis identified stromal PD-L1 expression (p = 0.008) and poorer differentiation (p < 0.001) as independent prognostic indicators. Furthermore, stromal PD-L1 expression was correlated to a high number of tumor-infiltrating lymphocytes (TILs). Stromal PD-L1– and low TIL groups had shorter OS than stromal PD-L1 + and high TIL groups (46.6% vs. 81.8%, p = 0.05) Stromal PD-L1-positive patients had longer disease-free survival (DFS) (p = 0.03) and time to surgical failure (p = 0.001). Interestingly, stromal PD-L1 expression was positively related to the desmoplastic subtype (p = 0.0002) and inversely related to the replacement subtype of the histological growth pattern (p = 0.008). Stromal PD-L1 expression may be a significant prognostic marker for CRLM.

Background and Aim The outcomes of immune checkpoint blockade for colorectal cancer (CRC) treatment are unsatisfactory. Furthermore, the efficacy of immune checkpoint blockade for liver metastasis of various cancer is poor. Here, we investigated the relationship between stromal programmed death-ligand 1 (PD-L1) expression and the prognosis of patients with colorectal cancer liver metastasis (CRLM). Methods The present study enrolled 84 CRLM patients who underwent surgery (R0) for CRC. Immunohistochemistry was performed to analyze stromal PD-L1 expression in CRLM. Results Stromal PD-L1 was expressed in 52.3% of CRLM samples, which was associated with a lower tumor grade (p=0.04) and fewer not optimally resectable metastases (p=0.04). Stromal PD-L1-positive patients had longer overall survival (p=0.003). Multivariate analysis identified stromal PD-L1 expression (p=0.008) and poorer differentiation (pp=0.05) Stromal PD-L1-positive patients had longer disease-free survival (DFS) (p=0.03) and time to surgical failure (p=0.001). Interestingly, stromal PD-L1 expression was positively related to the desmoplastic subtype (p=0.0002) and inversely related to the replacement subtype of the histological growth pattern (p=0.008). Conclusions Stromal PD-L1 expression may be a significant prognostic marker for CRLM.

Generation of hepatocytes from human adipose-derived mesenchymal stem cells (hADSCs) could be a promising alternative source of human hepatocytes. However, mechanisms to differentiate hepatocytes from hADSCs are not fully elucidated. We have previously demonstrated that our three-step differentiation protocol with glycogen synthase kinase (GSK) 3 inhibitor was effective to improve hepatocyte functions. In this study, we investigated the activation of the nuclear factor erythroid-2 related factor 2 (Nrf2) on hADSCs undergoing differentiation to HLC (hepatocyte-like cells). Our three-step differentiation protocol was applied for 21 days (Step 1:day 1-6, Step2:day 6-11, Step3:day 11-21). Our results show that significant nuclear translocation of Nrf2 occurred from day 11 until the end of HLC differentiation. Nuclear translocation of Nrf2 and CYP3A4 activity in the GSK3 inhibitor-treated group was obviously higher than that in Activin A-treated groups at day 11. The maturation of HLCs was delayed in Nrf2-siRNA group compared to control group. Furthermore, CYP3A4 activity in Nrf2-siRNA group was decreased at the almost same level in Activin A-treated group. Nrf2 translocation might enhance the function of HLC and be a target for developing highly functional HLC. J. Med. Invest. 70 : 343-349, August, 2023

Background: The role of the immune system in locally advanced rectal cancer (LARC) following preoperative chemoradiotherapy (CRT) has been widely investigated in recent years. This study examined the prognostic significance of indoleamine-pyrrole 2,3-dioxygenase (IDO) expression in patients with LARC who received preoperative CRT. Methods: Ninety patients with LARC who underwent preoperative CRT and curative resection were enrolled. IDO and programmed death-ligand 1 (PD-L1) expression was evaluated by immunohistochemistry. Results: Clinicopathological factors did not significantly differ between patients with positive or negative IDO expression, excluding the correlation of positive IDO expression with better tumor differentiation (p = 0.02). IDO expression was not associated with pathological response (p = 0.44), but it was associated with PD-L1 expression. The 5-year overall survival (OS) rate was significantly worse in the IDO-positive group than in the IDO-negative group (64.8% vs. 85.4%, p = 0.02). Univariate analysis identified IDO and PD-L1 expression (p = 0.02), surgical procedure (p = 0.01), final pathological stage (p = 0.003), lymph node metastasis (p < 0.001), and lymphatic invasion (p = 0.002) as significant prognostic factors for OS. Multivariate analysis revealed that IDO expression (HR: 7.10, p = 0.0006), surgical procedure (HR: 5.03, p = 0.01), lymph node metastasis (HR: 2.37, p = 0.04) and lymphatic invasion (HR: 4.97, p = 0.01) were independent prognostic indicators. Disease-free survival was not correlated with IDO or PD-L1 expression. Conclusions: IDO expression in patients with LARC who received preoperative CRT could be a potential prognostic indicator. IDO expression could be a useful marker for specifying individual treatment strategies in LARC.

Gastric carcinomas with lymphoid stroma (GCLS) are characterized by prominent stromal infiltration of lymphocyte and account for 1–4% of gastric cancers. Although, osteoclast-like giant cells (OGC) have been reported in some GCLS, OGCs in gastric tumors is exceedingly rare. A 60-year-old woman presented to our hospital after the finding of a positive fecal blood test during a routine medical check. Esophagogastroduodenoscopy revealed a Type 0-III + IIc tumor in the middle part of the gastric body. Biopsy revealed a poorly differentiated tumor and she was referred to our department. Early phase computed tomography showed thickening of the wall in the middle of the gastric body and enlargement of nearby lymph nodes. Laparoscopic total gastrectomy was performed. Pathological examination revealed a hamartomatous inverted polyp (HIP) in the submucosal layer with tub2-por1 tumor in the HIP. Prominent lymphocytic infiltration and OGCs were found around the tumor. Immunohistochemical analysis showed that the tumor cells were negative for EBER, MLH-1, and MSH2, 6. These findings suggest that this tumor was a non-microsatellite instability (MSI)-high GCLS without Epstein–Barr virus (EBV) infection. The patient’s postoperative course was uneventful and she was discharged 11 days after surgery. She remains well 3 years after surgery.

Purpose The concept of ‘diversity and inclusion’ is being adopted worldwide, but it is not yet understood well in Japan. We conducted this study to evaluate the impact of a lecture aimed at increasing awareness of academic careers and the benefits of having diversity and inclusion. Methods Two female surgeons delivered a 120-min lecture on “diversity and inclusion” to third-year medical students at Tokushima University. To assess the impact of the lecture, a questionnaire was distributed, for participants to complete anonymously before and after the lecture. Results Eighty-two students participated in the study (39 men, 38 women, and 5 unknown). Based on the questionnaire responses, 57.1% of the students had already perceived inequality in conduct because of gender. A comparison of pre- and post-lecture responses revealed a significant increase in confidence to succeed in their medical career (56.5% vs. 77.5%, p < 0.01). Learners were more likely to believe that gender would not become a barrier to career development (42.4% vs. 66.7%, p < 0.01). Moreover, 90.4% of the students felt positively about a career in surgery following the lecture. Conclusion The lecture promoted awareness about diversity, self-awareness, and career development and motivated students to consider specializing in surgery later in their career.