Evaluation of the efficacy of peritoneal lavage with distilled water in colorectal cancer surgery: in vitro and in vivo study

Gene polymorphisms associated with sudden decreases in heart rate during extensive peritoneal lavage with distilled water after gastrectomy

BACKGROUND

Our previous study found that the telomerase-associated protein 1 (TEP1, rs938886 and rs1713449) and homo sapiens RecQ like helicase 5 (RECQL5, rs820196) single nucleotide polymorphisms (SNPs) were associated with changes in heart rate (HR) ≥ 30% during peritoneal lavage with distilled water after gastrectomy. This study established a single tube method for detecting these three SNPs using two-dimensional (2D) polymerase chain reaction (PCR), and investigated whether SNP-SNP and SNP-environment interactions increase the risk of high HR variability (HRV).

AIM

To investigate whether genotypes, genetic patterns, SNP-SNP and SNP-environment interactions were associated with HRV.

METHODS

2D PCR was used to establish a single-tube method to detect TEP1 rs938886 and rs1713449 and RECQL5 rs820196, and the results were compared with those of sanger sequencing. After adjusting for confounders such as age, sex, smoking, hypertension, and thyroid dysfunction, a nonconditional logistic regression model was used to assess the associations between the genotypes and the genetic patterns (codominant, dominant, overdominant, recessive, and additive) of the three SNPs and a risk ≥ 15% or ≥ 30% of a sudden drop in HR during postoperative peritoneal lavage in patients with gastric cancer. Gene-gene and gene-environment interactions were analyzed using generalized multifactor dimensionality reduction.

RESULTS

The coincidence rate between the 2D PCR and sequencing was 100%. When the HRV cutoff value was 15%, the patients with the RECQL5 (rs820196) TC genotype had a higher risk of high HRV than those who had the TT genotype (odds ratio = 1.97; 95%CI: 1.05-3.70; P = 0.045). Under the codominant and overdominant models, the TC genotype of RECQL5 (rs820196) was associated with a higher risk of HR decrease relative to the TT and TT + CC genotypes (P = 0.031 and 0.016, respectively). When the HRV cutoff value was 30%, patients carrying the GC-TC genotypes of rs938886 and rs820196 showed a higher HRV risk when compared with the GG-TT genotype carriers (P = 0.01). In the three-factor model of rs938886, rs820196, and rs1713449, patients carrying the GC-TC-CT genotype had a higher risk of HRV compared with the wild-type GG-TT-CC carriers (P = 0.01). For rs820196, nonsmokers with the TC genotype had a higher HRV risk compared with nonsmokers carrying the TT genotype (P = 0.04). When the HRV cutoff value was 15%, patients carrying the TT-TT and the TC-CT genotypes of rs820196 and rs1713449 showed a higher HRV risk when compared with TT-CC genotype carriers (P = 0.04 and 0.01, respectively). Patients carrying the GC-CT-TC genotypes of rs938886, rs1713449, and rs820196 showed a higher HRV risk compared with GG-CC-TT genotype carriers (P = 0.02). When the HRV cutoff value was 15%, the best-fitting models for the interactions between the SNPs and the environment were the rs820196-smoking (P = 0.022) and rs820196-hypertension (P = 0.043) models. Consistent with the results of the previous grouping, for rs820196, the TC genotype nonsmokers had a higher HRV risk compared with nonsmokers carrying the TT genotype (P = 0.01).

CONCLUSION

The polymorphism of the RECQL5 and TEP1 genes were associated with HRV during peritoneal lavage with distilled water after gastrectomy.

Narrative review of theoretical considerations regarding HITHOC between past and future

Hyppocrates constructed the medicines-surgery-energy triangle which includes all therapeutical modalities. Hyperthermic intraoperative chemotherapy (HITHOC) is a synergy-based single stage multimodality treatment encompassing the locoregional manifestation of the systemic malignant process. Pleural space, thermal effect, lavage/irrigation and chemotherapy represent the basic science ports of the network hub: HITHOC. The malignant transformation and process of the pleural surface (and underlying lung) challenges space management and tissue control. Thermotherapy without local chemotherapy is insufficient, similar to the normothermic local irrigation aligned with anticancer agents. The local administration of combined heat-transfer fluid and chemotherapy with or without subsequent surgical removal offers reasonable outcome in extensive primary pleural neoplasms (malignant mesothelioma), advanced (> Stage IIIA) NSCLC, functionally inoperable lung cancer and pleural carcinosis from extrathoracic malignancies. Measured by symptom-free survival and the quality of life, HITHOC in its present form, offers a modest yet fully substantiated solution. HITHOC in combination with the local application of targeted therapy and/or immunotherapy administered in the pleural space are currently under investigation. Additional development including new acting substances, their solvents and the means regarding surgical delivery and anesthesiology techniques are sign posts up ahead. Level 2 evidence are required in order to stepping up the recommendation levels, rewriting protocols and guidelines, in which HITHOC earns its revered position in the decision making process it deserves.

Functional Analysis and Clinical Significance of Chloride Channel 2 Expression in Esophageal Squamous Cell Carcinoma

BACKGROUND

Chloride channel 2 (CLCN2) was recently shown to affect tumor behavior. The present study examined the functions of CLCN2 in the regulation of genes that play a role in tumor progression, as well as its clinicopathological significance in esophageal squamous cell carcinoma (ESCC).

METHODS

Knockdown experiments were conducted using CLCN2-small-interfering RNA, and changes in proliferation, survival, and cellular movement in human ESCC cell lines were investigated. A microarray analysis of gene expression profiles in CLCN2-depleted ESCC cells was conducted. Fifty-four primary ESCC samples were examined by immunohistochemistry (IHC).

RESULTS

The strong expression of CLCN2 was detected in TE5 and KYSE70 cells. Downregulated expression of CLCN2 enhanced proliferation and decreased apoptosis, whereas its upregulation inhibited proliferation and increased apoptosis. The effects of lubiprostone, a CLCN2 activator, were also investigated. In lubiprostone-treated cells, proliferation was inhibited and apoptosis was increased. The microarray analysis demonstrated that interferon (IFN) signaling-related genes were downregulated in CLCN2-depleted cells. IHC showed the presence of CLCN2 in the cytoplasm and cell membranes of ESCC cells. The prognostic analysis revealed a relationship between weak CLCN2 expression and shorter overall survival.

CONCLUSIONS

The present results indicate that tumor progression is regulated by CLCN2 through its effects on IFN signaling. Furthermore, weak CLCN2 expression was associated with poorer outcomes in ESCC patients. The present study will contribute to a clearer understanding of the role of CLCN2 as a mediator of ESCC, as well as its use as a biomarker for this cancer.

Effect of low temperature on the regulation of cell volume after hypotonic shock in gastric cancer cells

Although peritoneal lavage with distilled water performed after surgery prevents peritoneal seeding, cancer cells may avoid rupture under mild hypotonicity through regulatory volume decrease (RVD), which is the homeostatic regulation of ion and water transport. The aim of the present study was to investigate the effect of low temperature on cell volume and cell death under hypoosmolal conditions and determine the underlying molecular mechanisms in gastric cancer (GC). Three human GC cell lines (NUGC4, KATO‑III and MKN45) were exposed to hypotonic solutions, and the effects of low temperature on cell volume and viability were examined. Low temperature‑induced changes in membrane transporters were evaluated, and knockdown and overexpression experiments were conducted to determine their effects on cell volume during hypotonic stimulation. Low temperature (24˚C) during hypotonic stimulation inhibited RVD and enhanced the cytocidal effects on GC cells. The expression of leucine‑rich repeat containing protein A (LRRC8A), a component of a Cl‑ channel, was decreased, and aquaporin 5 (AQP5) expression was increased at low temperatures. LRRC8A knockdown markedly slowed the decrease in cell volume following cell swelling by hypotonic shock. AQP5 overexpression enhanced initial cell swelling after hypotonic shock and increased the final cell volume. These results suggest that a hypotonic solution at low temperature increased initial water influx via activation of AQP5 and decreased Cl‑ efflux via inhibition of LRRC8A. Therefore, low temperature enhanced the hypotonicity‑induced cytocidal effects on GC cells, and these results may contribute to the development of a novel lavage method effective in reducing peritoneal recurrence in GC.

LRRC8A Expression Influences Growth of Esophageal Squamous Cell Carcinoma

The volume-regulated anion channel is composed of leucine-rich repeat-containing protein A (LRRC8A) and is activated by hypotonic conditions to implement the process of regulatory volume decrease. The role of LRRC8A in regulating genes related to progression of esophageal squamous cell carcinoma (ESCC) was investigated, as well as the prognostic significance of LRRC8A expression in this tumor. Knockdown experiments were conducted using ESCC cell lines and LRRC8A siRNA to assess the influence of this protein on tumor function. In addition, the gene expression profile of ESCC was determined by microarray analysis. Immunohistochemistry was performed on 64 primary tumor samples from ESCC patients receiving radical esophagectomy. It was found that depletion of LRRC8A decreased cell proliferation and migration and also promoted apoptosis. Microarray data demonstrated G₁/S checkpoint regulation and up-regulation or down-regulation of phosphatidylinositol 3-kinase/AKT signaling, matrix metalloproteinase, and integrin signaling-related genes (including p21, p27, MMP1, and ITGAV) in LRRC8A-depleted cells. Immunohistochemistry showed that LRRC8A expression was related to the pathologic N and T stage categories, and strong LRRC8A expression was correlated with a worse prognosis of ESCC. These findings indicate that LRRC8A modulates tumor progression by influencing cell cycle, apoptosis, and migration, providing new insights into its function as an effector or biomarker of ESCC.

Gastric washing by distilled water can reduce free gastric cancer cells exfoliated into the stomach lumen

PURPOSE

Intragastric free cancer cells in patients with gastric cancer have rarely been studied. The purpose of this study was to investigate the detection rate of intragastric free cancer cells in gastric washes using two types of solutions during endoscopic examination. We further clarified risk factors affecting the presence of exfoliated free cancer cells.

METHODS

A total of 175 patients with gastric cancer were enrolled. Lactated Ringer's solution (N = 89) or distilled water (DW; N = 86) via endoscopic working channel was sprayed onto the tumor surface, and the resultant fluid was collected for cytological examination. We compared the cancer-cell positivity rate between the two (Ringer and DW) groups. We also tested the correlation between cancer-cell positivity and clinicopathological factors in the Ringer group to identify risk factors for the presence of exfoliated cancer cells.

RESULTS

The cancer-cell positivity rate was significantly higher in the Ringer group than that in the DW group (58 vs 6%). Cytomorphology in the Ringer group was well maintained, but not in the DW group. The larger tumor size (≥ 20 mm) and positive lymphatic involvement were significant risk factors of exfoliated free cancer cells.

CONCLUSIONS

Cancer cells can be highly exfoliated from the tumor surface into the gastric lumen by endoscopic irrigation in large gastric cancer with lymphatic involvement. Gastric washing by DW can lead to cytoclasis of free cancer cells; therefore, it may minimize the possibility of cancer-cell seeding in procedures carrying potential risks of tumor-cell seeding upon transluminal communication, such as endoscopic full-thickness resection and laparoscopy-endoscopy cooperative surgery.

Surgical stress response and promotion of metastasis in colorectal cancer: a complex and heterogeneous process

Surgery remains the curative treatment modality for colorectal cancer in all stages, including stage IV with resectable liver metastasis. There is emerging evidence that the stress response caused by surgery as well as other perioperative therapies such as anesthesia and analgesia may promote growth of pre-existing micro-metastasis or potentially initiate tumor dissemination. Therapeutically targeting the perioperative period may therefore reduce the effect that surgical treatments have in promoting metastases, for example by combining β-adrenergic receptor antagonists and cyclooxygenase-2 (COX-2) inhibitors in the perioperative setting. In this paper, we highlight some of the mechanisms that may underlie surgery-related metastatic development in colorectal cancer. These include direct tumor spillage at the time of surgery, suppression of the anti-tumor immune response, direct stimulatory effects on tumor cells, and activation of the coagulation system. We summarize in more detail results that support a role for catecholamines as major drivers of the pro-metastatic effect induced by the surgical stress response, predominantly through activation of β-adrenergic signaling. Additionally, we argue that an improved understanding of surgical stress-induced dissemination, and more specifically whether it impacts on the level and nature of heterogeneity within residual tumor cells, would contribute to the successful clinical targeting of this process. Finally, we provide a proof-of-concept demonstration that ex-vivo analyses of colorectal cancer patient-derived samples using RGB-labeling technology can provide important insights into the heterogeneous sensitivity of tumor cells to stress signals. This suggests that intra-tumor heterogeneity is likely to influence the efficacy of perioperative β-adrenergic receptor and COX-2 inhibition, and that ex-vivo characterization of heterogeneous stress response in tumor samples can synergize with other models to optimize perioperative treatments and further improve outcome in colorectal and other solid cancers.

Blockade of potassium ion transports enhances hypotonicity-induced cytocidal effects in gastric cancer

Background

Peritoneal lavage with distilled water has been used for surgeries of various cancers to reduce peritoneal recurrence. This study examined whether blockade of potassium ion transports enhances hypotonicity-induced cytocidal effects in gastric cancer (GC).

Results

A potassium channel blocker inhibited the occurrence of regulatory volume decrease (RVD) induced by mild hypotonic stimulation, and significantly enhanced cytocidal effects on GC cells. Incubating MKN45 cells with hypotonic solutions containing a potassium channel blocker significantly reduced the formation of peritoneal metastases in nude mice.

Methods

The three human GC cell lines (HGC-27, Kato III, and MKN45) were exposed to mild hypotonic solutions, and the effects of blockade of potassium ion transports during hypotonic stimulation on cell volume changes and cell viabilities were examined. In the in vivo study, MKN45 cells stimulated with mild hypotonic solutions were intraperitoneally injected into nude mice, and the effects of blockade of potassium ion transports during hypotonic stimulation on the formation of peritoneal metastases were evaluated.

Conclusions

Blockade of potassium ion transports enhances hypotonicity-induced cytocidal effects on GC cells, which may contribute to development of a novel lavage method for further reduction of peritoneal recurrence in GC.

Water lavage as an adjunct to cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC)

BACKGROUND

Water lavage (WL) during gastrointestinal cancer surgery has osmotically mediated lytic effects on tumor cells. We investigated the safety and efficacy of WL with CRS-HIPEC.

METHODS

This is a retrospective review, 1/2003-7/2014, of a single institution experience with CRS-HIPEC comparing patients who had WL (WL+) to those who did not (WL-).

RESULTS

Of 157 CRS-HIPECs, 16 (10.2%) were WL+. WL+ had more PCI scores >20 compared to WL- (56.3% vs 19.4%, respectively, p = 0.003); however, the completeness of cytoreduction (CC) was similar. There were no differences in hospital length of stay or post-operative complications. The average POD 1 sodium (Na) level was statistically lower in the WL+ group (133.6 ± 2.5 vs 135.5 ± 3.2 mEq/L, p = 0.023); however, the average Na at discharge for each group was 140 mEq/L. There were no differences in 3-year OS (3WL+:0.63 vs WL-:0.68, p = 0.97) or RFS (WL+:0.32 vs WL-:0.39, p = 0.47). A subset analysis for patients with PCI >20 showed no difference between groups.

CONCLUSIONS

WL offers a low cost, safe and theoretically efficacious method of tumor cell lysis for peritoneal malignancy.

Regulation of osmolality for cancer treatment

Disseminated metastasis is associated with a poor prognosis, and its management in the peritoneal or pleural cavity is crucial in the treatment of cancer. Recent studies show that ion and water transporters play important roles in fundamental cellular functions, including the regulation of cell volume that would be involved in the cancer process. Here, we review the evidence for hypotonic treatments of cancer and evaluate the potential of the cellular physiological approach in clinical management. The regulation of extracellular osmolality is a promising method, with several studies demonstrating the cytocidal effects of hypotonic solution on cancer cells. Peritoneal lavage with distilled water (DW) during surgery is reported to improve the survival rate of patients with spontaneously ruptured hepatocellular carcinoma. The in vitro studies included in this review also indicate the cytocidal effects of hypotonic shock on esophageal, gastric, colonic, pancreatic, and liver cancer cells with several unique methods and apparatuses, such as a differential interference contrast microscope connected to a digital video camera, a high-resolution flow cytometer and re-incubation analysis. The in vivo studies demonstrate the safeness of a peritoneal injection of DW into mice and indicate that the development of dissemination nodules can be prevented by the pre-incubation of cancer cells with DW or the peritoneal injection of DW. We also demonstrate that the blockade of Cl- channels/transporters enhances the cytocidal effects of hypotonic shock by inhibiting regulatory volume decrease in various cancer cells. A deeper understanding of molecular mechanisms may lead to the discovery of these cellular physiological approaches as a novel therapeutic strategy for disseminated metastasis.

Heat shock exerts anticancer effects on liver cancer via autophagic degradation of aquaporin 5

Previous studies described that the expression of aquaporin 5 (AQP5) was altered in tumors of various organs. AQP5 is attracting attention as a new cancer therapeutic target. In the present study, heat shock-induced changes in AQP5 expression were evaluated by immunofluorescent staining (IF) and western blotting (WB) of liver cancer cells. AQP5 knockdown experiments or a heat shock treatment were conducted, and their effects on cell volume, proliferation, cell cycle, the activity of apoptosis and migration/invasion were compared. Cycloheximide (CHX) chase experiments and double IF of AQP5 and light chain 3B (LC3B) were performed to investigate the mechanisms underlying changes in AQP5 expression. The results showed that IF and WB revealed decrease in AQP5 expression on cellular membranes and in the cytoplasm of heated cells. AQP5 knockdown and heat shock similarly decreased cell volume, suppressed migration/invasion and proliferation, and induced early apoptosis and partial G0/G1 arrest. CHX chase experiments revealed that heat shock accelerated the degradation of AQP5, which was rescued under CHX and the autophagy inhibitor, bafilomycin A1 (BafA1). Double IF showed the co-localization of AQP5 and LC3B on BafA1-treated heated cells. In conclusion, we demonstrated that heat shock decreased AQP5 on cellular membranes and in the cytoplasm by activating autophagic degradation, and heat shock and AQP5 knockdown exerted similar anticancer effects, suggesting that heat shock exerts anticancer effects via the autophagic degradation of AQP5.

Utilization of Distilled Water Lavage for Localized Fluid Collection After Combined Hepatectomy and Cyst Fenestration for Polycystic Liver Disease

Ascites necessitating persistent drainage or paracentesis after drain removal has been found among early postoperative complications after combined hepatectomy and cyst fenestration (CHCF) for polycystic liver disease (PLD). It has been reportedly observed in 20% to 70% of cases and seemed to easily cause recurrent symptoms unless properly treated. We utilized distilled water lavage for treating localized fluid collection after combined hepatectomy and cyst fenestration for PLD. A 63-year-old female patient underwent CHCF for PLD, which caused severe abdominal fullness. Early postoperative course was uneventful until 10 days after surgery when the patient suffered sudden abdominal fullness and resultant severe anorexia because of right subphrenic massive localized monolocular fluid collection diagnosed by abdominal computed tomography—although total liver volume was reduced to less than half of that before surgery. Percutaneous drainage relieved symptoms immediately, but the drainage tube could not be removed because of massive outflow. Then we utilized distilled water lavage for treating this condition. After that, drain outflow dramatically reduced and the drainage tube was successfully removed. Total liver volume of the patient continued to reduce up to 1 year after surgery and retained less than one-third of preoperative total liver volume thereafter. Sustained reduction of total liver volume in the present case suggested a sclerosant effect of hypotonic cytocidal property of distilled water for cyst endothelium and/or retrieved effectiveness of fenestration. Hence, we consider this approach to be useful for patients with PLD receiving CHCF and thus present it here.

Inhibition of Regulatory Volume Decrease Enhances the Cytocidal Effect of Hypotonic Shock in Hepatocellular Carcinoma

Background: Hypotonic shock induces cytocidal effects through cell rupture, and cancer therapy based on this mechanism has been clinically administered to hepatocellular carcinoma patients. We herein investigated the effectiveness of hypotonic shock combined with the inhibition of regulatory volume decrease as cancer therapy for hepatocellular carcinoma.

Methods: Morphological changes in human hepatocellular carcinoma cell lines were observed under a differential interference contrast microscope connected to a high-speed digital video camera. Cell volume changes under hypotonic shock with or without chloride, potassium, or water channel blockers were observed using a high-resolution flow cytometer. In order to investigate cytocidal effects, the number of surviving cells was compared after exposure to hypotonic solution with and without each channel blocker (re-incubation experiment).

Results: Video recordings showed that cells exposed to distilled water rapidly swelled and then ruptured. Cell volume measurements revealed regulatory volume decrease under mild hypotonic shock, whereas severe hypotonic shock increased the number of broken fragments as a result of cell rupture. Moreover, regulatory volume decrease was inhibited in cells treated with each channel blocker. Re-incubation experiments showed the cytocidal effects of hypotonic shock in cells exposed to hypotonic solution, and additional treatments with each channel blocker enhanced these effects.

Conclusion: The inhibition of regulatory volume decrease with chloride, potassium, or water channel blockers may enhance the cytocidal effects of hypotonic shock in hepatocellular carcinoma. Hypotonic shock combined with the inhibition of regulatory volume decrease was a more effective therapy than hypotonic shock alone.

Animal models of colorectal peritoneal metastasis

Colorectal cancer remains an important cause of mortality worldwide. The presence of peritoneal carcinomatosis (PC) causes significant symptoms and is notoriously difficult to treat. Therefore, informative preclinical research into the mechanisms and possible novel treatment options of colorectal PC is essential in order to improve the prognostic outlook in these patients. Several syngeneic and xenograft animal models of colorectal PC were established, studying a wide range of experimental procedures and substances. Regrettably, more sophisticated models such as those giving rise to spontaneous PC or involving genetically engineered mice are lacking. Here, we provide an overview of all reported colorectal PC animal models and briefly discuss their use, strengths, and limitations.

Distilled Water Lavage During Surgery Improves Long-Term Outcomes of Patients with Ruptured Hepatocellular Carcinoma

BACKGROUND

Rupture of hepatocellular carcinoma (HCC) releases tumor cells and furthers peritoneal metastasis. The present study investigated the killing effects of distilled water (DW) on HCC cells and the clinical outcomes of patients undergoing liver resection with DW lavage for spontaneously ruptured HCC.

MATERIALS AND METHODS

Human HCC cells (BEL-7402, SMMC7721) were treated with DW, the morphological changes observed, and cell viability measured. DW-treated HCC cells were also injected intraperitoneally into nude mice, and the formation of tumor nodules and overall survival (OS) measured. The clinicopathological data of 141 consecutive patients undergoing liver resection for spontaneously ruptured HCC during 1998-2011 were retrospectively reviewed.

RESULTS

Fifteen minutes of DW exposure caused complete cell lysis of HCC cells in vitro and completely prevented tumor formation and prolonged survival time in nude mice. Among the 141 patients, the 1-, 3-, and 5-year disease-free survival (DFS) and OS rates in patients administered DW lavage during surgery were 68.9, 24.6, and 6.6%, respectively, and 95.1, 65.1, and 40%, respectively, which were significantly higher than those in patients who did not (P < 0.05). DW lavage was an independent predictor of recurrence (odds ratio (OR), 0.34; 95% confidence interval (CI), 0.23-0.51; P < 0.001) and OS (OR, 0.35; 95% CI, 0.23-0.53; P < 0.001).

CONCLUSIONS

Fifteen minutes of DW lavage can effectively kill HCC cells in vitro and prevent tumor formation in vivo. DW lavage significantly improves long-term outcomes in patients undergoing liver resection for spontaneously ruptured HCC and could be administered intra-operatively when tumor cell liberation is suspected.