microRNAs Associated with Gemcitabine Resistance via EMT, TME, and Drug Metabolism in Pancreatic Cancer

Despite extensive research, pancreatic cancer remains a lethal disease with an extremely poor prognosis. The difficulty in early detection and chemoresistance to therapeutic agents are major clinical concerns. To improve prognosis, novel biomarkers, and therapeutic strategies for chemoresistance are urgently needed. microRNAs (miRNAs) play important roles in the development, progression, and metastasis of several cancers. During the last few decades, the association between pancreatic cancer and miRNAs has been extensively elucidated, with several miRNAs found to be correlated with patient prognosis. Moreover, recent evidence has revealed that miRNAs are intimately involved in gemcitabine sensitivity and resistance through epithelial-to-mesenchymal transition, the tumor microenvironment, and drug metabolism. Gemcitabine is the gold standard drug for pancreatic cancer treatment, but gemcitabine resistance develops easily after chemotherapy initiation. Therefore, in this review, we summarize the gemcitabine resistance mechanisms associated with aberrantly expressed miRNAs in pancreatic cancer, especially focusing on the mechanisms associated with epithelial-to-mesenchymal transition, the tumor microenvironment, and metabolism. This novel evidence of gemcitabine resistance will drive further research to elucidate the mechanisms of chemoresistance and improve patient outcomes.

Preoperative C-Reactive Protein-to-Albumin Ratio Predicts Postoperative Pancreatic Fistula following Pancreatoduodenectomy: A Single-Center, Retrospective Study

Postoperative pancreatic fistula (POPF) following pancreatoduodenectomy (PD) is a potentially lethal complication, and it is clinically important to determine its risk preoperatively. Although C-reactive protein-to-albumin ratio (CAR) is reported to be a prognostic marker for postoperative complications in several cancers, no evidence is currently available regarding the association between preoperative CAR and POPF following PD for periampullary tumors. This study examined whether preoperative CAR could predict POPF following PD. Clinical data were retrospectively retrieved from Ehime University Hospital. The optimal cut-off value for CAR was determined using receiver operating characteristic (ROC) curve analysis. This study enrolled 203 consecutive patients undergoing PD for periampullary tumors. The CAR value was significantly higher in the POPF group than in the non-POPF group (p < 0.001). According to the ROC curve analysis, the optimal cut-off value for CAR was 0.09. Patients with CAR ≥ 0.09 had higher incidence rates of POPF than their counterparts. CAR ≥ 0.09 was a risk factor for POPF in the multivariate logistic regression analysis (odds ratio 34.5, 95% confidence interval 11.75-101.38, p < 0.001). This is the first report demonstrating an association between CAR and POPF following PD. Preoperative CAR is an independent predictive marker for POPF following PD.

Association between the Preoperative C-Reactive Protein-to-Albumin Ratio and the Risk for Postoperative Pancreatic Fistula following Distal Pancreatectomy for Pancreatic Cancer

Postoperative pancreatic fistula (POPF) are major postoperative complications (POCs) following distal pancreatectomy (DP). Notably, POPF may worsen the prognosis of patients with pancreatic cancer. Previously reported risks for POCs include body mass index, pancreatic texture, and albumin levels. Moreover, the C-reactive protein-to-albumin ratio (CAR) is a valuable parameter for prognostication. On the other hand, POCs sometimes lead to a worse prognosis in several cancer types. Thus, we assumed that CAR could be a risk factor for POPFs. This study investigated whether CAR can predict POPF risk in patients with pancreatic cancer following DP. This retrospective study included 72 patients who underwent DP for pancreatic cancer at Ehime University between January 2009 and August 2022. All patients underwent preoperative CAR screening. Risk factors for POPF were analyzed. POPF were observed in 17 of 72 (23.6%) patients. POPF were significantly associated with a higher CAR (p = 0.001). The receiver operating characteristic curve analysis determined the cutoff value for CAR to be 0.05 (sensitivity: 76.5%, specificity: 88.9%, likelihood ratio: 6.88), indicating an increased POPF risk. Univariate and multivariate analysis revealed that CAR ≥ 0.05 was a statistically independent factor for POPF (p < 0.001, p = 0.013). Therefore, CAR has the potential to predict POPF following DP.

Geriatric nutritional risk index as a potential prognostic marker for patients with resectable pancreatic cancer: a single-center, retrospective cohort study

In pancreatic cancer, postoperative complications (POCs) are associated with disease outcomes. The geriatric nutritional risk index (GNRI) is known to predict POCs after pancreatoduodenectomy (PD) or distal pancreatectomy (DP) in patients with hepatobiliary pancreatic tumors, including pancreatic cancer. Through POC occurrence risk, we aimed to determine whether GNRI could predict prognosis in patients who underwent PD or DP for resectable pancreatic cancer. This retrospective study examined 139 patients who underwent radical pancreatectomy for resectable pancreatic cancer at Ehime University. All patients were subjected to nutritional screening using GNRI and were followed up for POC diagnosis and patient outcomes such as overall survival (OS). Patients were divided based on the GNRI value of 99 (Low group: N = 74, GNRI < 99; High group: N = 65, GNRI ≥ 99), which was determined by receiver operating characteristic curve analysis. Multivariate analysis showed that GNRI < 99 was statistically correlated with POCs after curative pancreatic resection (p = 0.02). Univariate and multivariate analyses confirmed that GNRI < 99 was significantly associated with long OS (p = 0.04). GNRI could be a potential prognostic marker for resectable pancreatic cancer after curative pancreatic resection despite being a simple and noninvasive approach.

A case of radical resection for brain metastases of pancreatic cancer after curative chemotherapy for para-aortic lymph node metastases

Background

The incidence of brain metastasis of pancreatic cancer has been reported to be approximately 0.3%. The blood–brain barrier of the central nervous system restricts the transfer of substances, including chemotherapeutic agents, from the bloodstream. It is hypothesized that brain metastasis may occur despite successful chemotherapy for the primary tumor. Herein, we report a case of brain metastases of pancreatic cancer that occurred after chemotherapy and discuss relevant literature.

Case presentation

A 64-year-old man underwent distal pancreatectomy with D2 lymph node dissection for resectable pancreatic tail cancer. Invasive ductal carcinoma of pancreas, pT3N2M0 pStageIII (TNM Classification of Malignant Tumors, UICC 8th edition) was diagnosed. S-1 adjuvant chemotherapy was initiated. Three months postoperatively, CA19-9 had increased to 619 U/mL. Additionally, contrast-enhanced computed tomography (CT) and fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT revealed local recurrence in the para-aortic lymph nodes. Chemotherapy was revised to a combined regimen of gemcitabine and nab-paclitaxel. After 4 cycles, tumor markers were normalized. After 5 cycles, recurrence could not be identified on contrast-enhanced CT; therefore, the patient was adjudged to be in complete remission. However, after 29 cycles of chemotherapy, the patient had symptoms of raised intracranial pressure. Magnetic resonance imaging showed two metastatic lesions of 20 mm and 32 mm in the left frontal lobe and cerebellum, respectively. Quasi-emergency resection of the metastatic brain tumors was performed. Pathological examination revealed that the resected specimens originated from primary pancreatic cancer. The patient was discharged on postoperative day 12, without any complications. Postoperatively, a total of 53 Gy of local brain radiation therapy was added. On postoperative day 30, blood carcinoembryonic antigen level had decreased to 5.4 ng/dl and all other tumor markers were negative. Additionally, tumor markers of the cerebrospinal fluid were markedly reduced and the cytology was negative for tumor cells. These results suggested complete resection of the metastatic brain tumors.

Conclusions

Aggressive resection and salvage stereotactic radiotherapy for metastatic brain tumors may lead to complete cure and a good long-term prognosis.

Utility of Robot-assisted Laparoscopic Transabdominal Preperitoneal Repair of Inguinal Hernia Following Robot-assisted Laparoscopic Radical Prostatectomy

BACKGROUND

To evaluate the utility of robot-assisted laparoscopic transabdominal preperitoneal repair (R-TAPP) of postprostatectomy inguinal hernia (PIH) in patients who underwent robot-assisted laparoscopic radical prostatectomy (RALP).

PATIENTS AND METHODS

This was a prospective, single-centre retrospective cohort study. R-TAPP was conducted in 74 consecutive patients from September 2016 to March 2020. With the exception of women and patients who underwent previous abdominal surgery, 70 patients were classified into two groups based on the absence or presence of PIH. Their data were retrospectively compared to those who had not undergone RALP.

RESULTS

The median operative time for the PIH group was longer compared to the non-PIH group. However, postoperative complications, including seroma formation, haematoma and surgical site infections, were not significantly different between the groups. The estimated blood loss was small, and hospitalisation duration was 1 day in all cases. Moreover, there were no hernia recurrences within the 90-day follow-up period in either group.

CONCLUSION

R-TAPP is a feasible and safe approach for inguinal hernia repair, even in patients who undergo RALP for prostate cancer.

Evaluation of accuracy of laparoscopic liver mono-segmentectomy using the Glissonian approach with indocyanine green fluorescence negative staining by comparing estimated and actual resection volumes: A single-center retrospective cohort study

BACKGROUND/PURPOSE

Laparoscopic liver mono-segmentectomy (LLMS) may improve patient outcomes, but it is difficult and its accuracy and safety are unknown. We evaluated the accuracy of LLMS using Glissonian approach with indocyanine green fluorescence (ICG) negative staining.

METHODS

Seventy-four patients eligible for LLMS except for segment 1 were enrolled. Preoperative three-dimensional CT-based surgical simulation was used to determine estimated liver resection volume (ELRV), which was compared with modified actual liver resection volume (ALRV) obtained from actual liver resection mass. The LLMS accuracy was also evaluated based on operator's experience (attending surgeon [AS] or trainee surgeon [TS]).

RESULTS

Estimated liver resection volumes significantly correlated with ALRVs (r = .82) in all cases. Moreover, TS-conducted LLMS also showed acceptable difference between ELRV and ALRV compared with AS-conducted LLMS. There were no intergroup differences in estimated blood loss, operation time, time of Pringle maneuver, postoperative complications, and length of postoperative hospitalization (P < .05). Moreover, R0 resection was comparable between the AS and TS groups.

CONCLUSIONS

Laparoscopic liver mono-segmentectomy with Glissonian approach using ICG negative imaging ensured safe and accurate procedure owing to facilitated visualization of the resection line. Our approach was effective in avoiding postoperative liver dysfunction and securing radical resection. In addition, it might be helpful in TS education of LLMS.

Geriatric nutritional risk index serves as risk factor of surgical site infection after pancreatoduodenectomy: a validation cohort Ageo study

Background

Surgical site infections (SSIs), which are associated with preoperative malnutrition, are a well-known potential complication of surgery that leads to increased medical costs and longer hospitalizations. Thus, surgeons need to accurately identify patients at high-risk for SSIs. Considering that the Geriatric Nutritional Risk Index (GNRI) was designed to assess the degree of malnutrition specifically among elderly patients, previous evidence (Kawaguchi study) proved that GNRI predicted the risk of SSIs in patients following pancreatoduodenectomy (PD). In this study, we aimed to validate whether that the same index could predict the risk of SSI among patients who underwent PD in our patient cohort (Ageo study).

Methods

The current validation cohort study was retrospectively conducted on 93 patients at the Department of Surgery, Ageo Central General Hospital, Japan, from January 2015 to October 2019. All patients were subjected to nutritional screening using the GNRI and were followed up for the occurrence of postoperative complications. Additionally, risk factors for developing SSI, as well as patient's height, body mass index, and preoperative laboratory values, were recorded.

Results

Patients were divided into the SSI (N=30) and non-SSI (N=63) groups with a determined SSI incidence rate of 32.3% (30/93). The SSI group had significantly lower GNRI than the non-SSI group (P<0.001). Receiver operating characteristic curve analysis determined a cutoff GNRI value of 94 (sensitivity, 83.3%; specificity, 83.6%), similar to that in the previous study. Univariate and multivariate analyses confirmed that a GNRI of <94 was significantly associated with SSI (P<0.001).

Conclusions

The present Ageo study confirmed the consistency of results in Kawaguchi study. Thus, lower GNRI can be a universal marker for SSI risk following PD.

Geriatric Nutritional Risk Index Less Than 92 Is a Predictor for Late Postpancreatectomy Hemorrhage Following Pancreatoduodenectomy: A Retrospective Cohort Study

Simple Summary

The definite risk factor of postpancreatectomy hemorrhage (PPH) is still unknown in spite of a lethal complication of pancreatoduodenectomy (PD). In this study, we evaluated whether GNRI is a reliable marker for PPH following PD. The present study retrospectively evaluated 121 patients treated with PD at Ageo Central General Hospital in Japan. Ten patients had developed PPH. Among them, the patients were divided into bleeding group (n = 10) and non-bleeding group (n = 111). The bleeding group had significantly low geriatric nutritional risk index (GNRI) values compared to those in the non-bleeding group (p = 0.001). The cut-off value of GNRI was determined by 92 accounting for a sensitivity 80.0%, specificity 82.9% using receiver operating characteristic curve analysis. A GNRI of <92 was statistically identified as an independently risk factor of PPH risk following PD.

Abstract

Postpancreatectomy hemorrhage (PPH) is the most lethal complication of pancreatoduodenectomy (PD). The main risk factor for PPH is the development of a postoperative pancreatic fistula (POPF). Recent evidence shows that the geriatric nutritional risk index (GNRI) may be predictive indicator for POPF. In this study, we aimed to evaluate whether GNRI is a reliable predictive marker for PPH following PD. The present study retrospectively evaluated 121 patients treated with PD at Ageo Central General Hospital in Japan between January 2015 and March 2020. We investigated the potential of age, gender, body mass index, serum albumin, American Society of Anesthesiologists classification (ASA), diabetes mellitus and smoking status, time taken for the operation, estimated blood loss, and postoperative complications (POPF, bile leak, and surgical site infections) to predict the risk of PPH following PD using univariate and multivariate analyses. Ten patients had developed PPH with an incidence of 8.3%. Among them, the patients were divided into bleeding group (n = 10) and non-bleeding group (n = 111). The bleeding group had significantly lower GNRI values than those in the non-bleeding group (p = 0.001). We determined that the cut-off value of GNRI was 92 accounting for a sensitivity 80.0%, specificity 82.9%, and likelihood ratio of 4.6 using receiver operating characteristic curve analysis. A GNRI of <92 was statistically associated with PPH in both univariate (p < 0.001) and multivariate analysis (p = 0.01). Therefore, we could identify that a GNRI < 92 was an independently potential predictor of PPH risk following PD. We should alert surgeons if patients have low level GNRI before PD.

Pure Laparoscopic Right Hepatectomy for Hepatocellular Carcinoma with Bile Duct Tumor Thrombus (with Video)

BACKGROUND

Laparoscopic liver resection has been increasingly utilized due to its less invasiveness approach compared with open surgery,1^-3 but often creates challenges. Hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) portends a poorer prognosis and often precludes patients from potential liver resection.4^-6 We herein report a case of laparoscopic hepatectomy and thrombectomy in a patient with HCC and BDTT.

METHODS

CT, ERCP, and POCS showed a 40-mm tumor located in the right lobe with BDTT. A five 12-mm trocar was inserted at the umbilicus for laparoscope, the epigastrium, both sides of the hypochondrium, and right lateral region. Moreover, a 5-mm trocar was inserted at left hypochondrium. After cholecystectomy, hepatoduodenal ligament was encircled using the tourniquet through 5-mm trocar site. The right portal vein was transected by stapler following transection of the right hepatic artery. After ICG staining (0.5 mg/body i.v.),7 hepatic parenchymal transection was performed using clamp-crashing technique. Moreover, CUSA also was used near Glissonian sheath. BDTT was removed from the right BD. Moreover, the cholangioscopy confirmed no BDTT remnants. The resection stump was then sutured. Finally, the right hepatic vein was divided with a stapler. A drainage tube was placed in the right subphrenic space. Operation time was 496 min, and blood loss was 91 ml. The patient was discharged without complications on postoperative day 11. Pathological diagnosis showed moderately differentiated HCC, tumor size 40 × 45 mm with negative surgical margins.

CONCLUSIONS

Pure laparoscopic resection for HCC with BDTT is a radical, yet feasible procedure.

Lower geriatric nutritional risk index predicts postoperative pancreatic fistula in patients with distal pancreatectomy

Postoperative pancreatic fistula (POPF) is a common complication following pancreatic resection. It leads to increased medical costs, and longer hospital stays. However, the risk factors of POPF are still unclear, and therefore, this urgent clinical issue should be resolved. The geriatric nutritional risk index (GNRI) is tool to assess the nutritional status using body weight, and serum albumin value, particularly in elderly patients. On the other hand, POPF is associated with body mass index (BMI). Thus, the present study aimed to investigate whether GNRI can predict the risk of POPF in patients after distal pancreatectomy (DP). We conducted a retrospective cohort study involving 37 patients who were treated at the Department of Digestive Surgery, Kawaguchi Municipal Medical Center between January 2007 and June 2018. All patients were subjected to nutritional screening using GNRI, and were followed up after DP for postoperative complications including POPF. In addition, risk factors of POPF, and patient's height, BMI, and preoperative laboratory values were analyzed. POPF was observed in 7 of the 37 (19%) patients. Those with a POPF had significantly lower GNRI values than those without POPF (P<0.001). Receiver operating characteristic curve analysis was performed to determine a cut-off value of GNRI, which indicated an increased risk of POPF. This value was determined as 96 (sensitivity: 71.4%, specificity: 86.7%, likelihood ratio: 5.36). Univariate analysis confirmed that a GNRI of <96 was significantly associated with POPF (P=0.005), and a multivariate logistic regression analysis revealed that a GNRI of <96 was significant independent predictor of POPF (P=0.005), suggesting its utility for assessing the risk of POPF following DP.

Cavernous Hemangioma of the Gallbladder Masquerading as a Carcinoma

Cavernous hemangioma arising from the gallbladder is extremely rare. Here, we report a cavernous hemangioma of the gallbladder masquerading as a carcinoma. A 75-year-old man was referred to our institution for a follow-up study after gastrectomy. Abdominal computed tomography revealed that the gallbladder was filled with a low-density mass with calcification of the wall. The patient underwent extended cholecystectomy. Histologically, the tumor consisted of vascular endothelial cellular elements and hematomas. The postoperative course was uneventful without complications. Presently, only 7 cases of cavernous hemangioma of the gallbladder have been previously reported. This case serves as an important reminder to consider benign tumors including cavernous hemangioma when investigating all possible causes of a gallbladder tumor.

MicroRNA-200b and -301 are associated with gemcitabine response as biomarkers in pancreatic carcinoma cells

Chemotherapy resistance (congenital or acquired) is one of the principal challenges for the treatment of pancreatic carcinoma. Recent evidence has demonstrated that epithelial to mesenchymal transition (EMT) is associated with chemoresistance in pancreatic carcinoma cells. However, the molecular mechanism underlying the development of chemoresistance remains unknown, and limited therapeutic options are available. Therefore, to anticipate individual chemosensitivity or acquired chemoresistance for patients with pancreatic carcinoma, predictive biomarkers are urgently required. Extensive evidence suggests that microRNAs (miRNAs) serve a crucial role in regulating EMT. The aim of this study was to examine the potential role of miRNA (miR)‑200b and miR‑301 in predicting the chemo‑responses to treatment for pancreatic carcinoma. The present results demonstrate that miR‑200b expression predicted chemo‑sensitivity and may have potential as a biomarker. In six different pancreatic carcinoma cell lines (Capan‑1, Capan‑2, Panc‑1, MIAPaCa‑2, BxPC‑3 and PL45 cells), the expression of miR‑200b correlated positively with chemosensitivity. Moreover, the enhanced expression of miR‑200b increased chemosensitivity and induced mesenchymal to epithelial transition. Conversely, miR‑301 modulated gemcitabine resistance and induced EMT through the downregulation of cadherin 1 expression. In addition, gemcitabine‑resistant cells (Capan‑2 and Panc‑1) exhibited upregulated miR‑301 expression and downregulated gemcitabine‑induced apoptosis. In summary, these two miRNAs may serve roles as biomarkers in pancreatic carcinoma, miR‑200b expression may predict chemosensitivity, and elevated miR‑301 expression may have potential applications in the prediction of acquired gemcitabine resistance.

Intestinal obstruction caused by primary adenosquamous cell carcinoma of the small intestine: A case report and review of the literature

Primary adenosquamous cell carcinoma (ASCC) arising from the ileum is an exceptionally rare malignant neoplasm exhibiting mixed glandular and squamous differentiation. The clinicopathological characteristics of ASCC have not been clearly determined due to its rarity. We herein report a case of a 74-year-old man with a successfully treated ASCC of the ileum. The patient visited a medical clinic due to abdominal pain. Abdominal computed tomography imaging revealed an intestinal tumor in the ileum. Prior to undergoing capsule endoscopy, the patient complained of severe abdominal pain due to intestinal obstruction from the patency capsule and the tumor. Thus, the patient was referred to our hospital for emergency surgery. Upon relieving the obstruction by partial resection of the ileum, an impacted patency capsule with a tumor with ulceration was identified. On histological examination, the tumor consisted of malignant glandular and squamous cell elements. The postoperative course was uneventful, without complications. The patient subsequently received adjuvant chemotherapy with oxaliplatin and capecitabine for 6 months. The patient has no evidence of recurrence 20 months after surgery. To the best of our knowledge, only 8 cases of ASCC have been reported in the English literature to date. This case serves as an important reminder to consider small intestinal carcinoma, including ASCC, in the differential diagnosis of intestinal obstruction.

Geriatric nutritional risk index predicts surgical site infection after pancreaticoduodenectomy

Surgical site infections (SSIs) are a well-known potential complication of surgery. They are assocaited with preoperative malnutrition and lead to increased medical costs and longer hospital stays. Therefore, surgeons should appropriately identify patients who are at a high risk. The geriatric nutritional risk index (GNRI) is a tool, increasingly utilized to assess the degree of malnutrition, particularly in elderly patients. Therefore, the present study attempted to validate whether GNRI could predict the risk of SSI in patients following pancreaticoduodenectomy (PD). A cohort study was retrospectively conducted on 106 patients in the Department of Digestive Surgery, Kawaguchi Municipal Medical Center, Japan from January 2007 to December 2017. All patients were subjected to nutritional screening using GNRI and followed up for the occurrence of postoperative complications, including SSI post PD. Additionally, risk factors for developing SSI, and the patient's height, body mass index and preoperative laboratory values were documented. Patients were divided into SSI (n=15) and non-SSI (n=91) groups with a determined incidence of 14.2% (15/106) for SSI. The results revealed that the SSI group had GNRI values that were significantly reduced compared with the non-SSI group (P<0.001). Receiver operating characteristic curve analysis was performed to determine the cut-off value of GNRI that conferred an increased risk of SSI; it was determined as 94 (sensitivity 80.0%, specificity 83.5%). Univariate analysis confirmed that a GNRI <94 was significantly associated with SSI (P<0.001), whereas multivariate logistic regression analysis revealed that a GNRI <94 was independently associated with SSI following PD (relative risk=1.73, 95% confidence interval=1.23-2.43; P<0.001). Therefore, a GNRI <94 is a potential predictive marker for SSI risk following PD.

MicroRNA-203 induces apoptosis by upregulating Puma expression in colon and lung cancer cells

The present study investigated the relationship between microRNA-203 (miR-203) and the p53 upregulated modulator of apoptosis (Puma) in colon (HCT116) and lung cancer (A549) cells. Colon and lung cancer cell lines were selected for this study since a relationship between p53/miR-203 and p53/Puma has been established in both cancers. In the present study, adriamycin and nutlin-3 were used to activate p53, which induced both miR-203 and Puma expression in HCT116 cells. In contrast, HCT 116 cells with downregulated p53 showed decreased miR-203 and Puma expression. Importantly, we found that overexpressed miR-203 in HCT116 cells resulted in significantly increased Puma expression (P<0.05). Based on these findings, we hypothesized that another limb of the p53/Puma axis depends on miR-203 expression. To further validate this relationship, we used lung cancer cells (A549) and found that activated p53 increased both miR-203 and Puma expression. In addition, we found that Puma expression remained elevated in cells with overexpressed miR-203 in the presence of p53 downregulation. Cumulatively, our data purport that p53 not only increased Puma expression directly, but that it may also do so through miR-203. Additionally, functional studies revealed that miR-203 overexpression induced apoptosis and inhibited cell invasiveness.

Tetrahydrouridine inhibits cell proliferation through cell cycle regulation regardless of cytidine deaminase expression levels

Tetrahydrouridine (THU) is a well characterized and potent inhibitor of cytidine deaminase (CDA). Highly expressed CDA catalyzes and inactivates cytidine analogues, ultimately contributing to increased gemcitabine resistance. Therefore, a combination therapy of THU and gemcitabine is considered to be a potential and promising treatment for tumors with highly expressed CDA. In this study, we found that THU has an alternative mechanism for inhibiting cell growth which is independent of CDA expression. Three different carcinoma cell lines (MIAPaCa-2, H441, and H1299) exhibited decreased cell proliferation after sole administration of THU, while being unaffected by knocking down CDA. To investigate the mechanism of THU-induced cell growth inhibition, cell cycle analysis using flow cytometry was performed. This analysis revealed that THU caused an increased rate of G1-phase occurrence while S-phase occurrence was diminished. Similarly, Ki-67 staining further supported that THU reduces cell proliferation. We also found that THU regulates cell cycle progression at the G1/S checkpoint by suppressing E2F1. As a result, a combination regimen of THU and gemcitabine might be a more effective therapy than previously believed for pancreatic carcinoma since THU works as a CDA inhibitor, as well as an inhibitor of cell growth in some types of pancreatic carcinoma cells.

Hydroxyurea decreases gemcitabine resistance in pancreatic carcinoma cells with highly expressed ribonucleotide reductase

OBJECTIVES

This study aimed to determine whether the treatment of pancreatic carcinoma can be defined on the basis of the expression of genes involved in gemcitabine metabolism and whether combination treatment is more effective than conventional treatment.

METHODS

Four pancreatic carcinoma cell lines (Panc-1, MIAPaCa-2, BxPC-3, and Capan-2) were used to determine the patterns of gemcitabine-metabolizing genes and mesenchymal marker gene expressions using quantitative real-time polymerase chain reaction. Chemosensitivity and cell proliferation were measured using colorimetric assay. Gemcitabine was combined with hydroxyurea or small interfering RNA targeting ribonucleotide reductase to assess changes in chemoresistance.

RESULTS

Panc-1 and MIAPaCa-2 cell lines were profoundly chemoresistant and expressed genes corresponding to cells with distinct mesenchymal phenotypes. In addition, Panc-1 highly expressed ribonucleotide reductase and showed a 4-fold increase in gemcitabine sensitivity after treatment with hydroxyurea.

CONCLUSIONS

Combination treatment tailored to cells with highly expressed ribonucleotide reductase was more effective than treatment with gemcitabine alone. Moreover, phenotype and gemcitabine metabolism may independently confer chemoresistance.

Cohort study of wound infection for benign hepato-biliary disease with open laparotomies

BACKGROUND/AIMS

Surgical site infection (SSI) is still a source of major complications in digestive tract surgery, especially in hepatobiliary region. To decrease the incidence of SSI, we have investigated whether methods of intradermal suture in benign hepatobiliary patients are in fact useful.

METHODOLOGY

Cohort study was carried out to compare the intradermal suture group (ISG) and the metallic stapler group (MSG) for laparotomy of benign biliary tract disease. The surgical technique employed for SSI prevention was always the same, excluding the method of skin sutures. Wounds with pus were defined as infected if pus were observed after the surgery. All patients were followed for at least 3 months after their respective operations.

RESULTS

The incidence of SSI in ISG was lower than in MSG (p < 0.05). However, the risk factors and the incidence of wound infection did not correlate with each other statistically.

CONCLUSION

In cases of benign biliary tract disease, intradermal suture seemed to be quite appropriate for prevention of SSI, even though operation time was a little longer than with use of a metallic stapler.