Heparanase expression in blood is sensitive to monitor response to anticancer treatment in pancreatic cancer, a pilot study.

BACKGROUND: /Objectives: High heparanase level was shown in maliganant tumor; however, whether or not heparanase may serve as a sensitive marker to monitor response to anticancer treatment is still unknown. METHODS: In the pilot study, heparanase mRNA expression in peripheral blood mononuclear cell fraction (PBMC) and activity in plasma and urine were detected by quantitative real time RT-PCR and heparan-degrading enzyme assay in 31 pancreatic cancer patients. RESULTS: Heparanase mRNA and activity in samples from cancer patients were significantly higher than that in healthy donors. Both heparanase mRNA and activity in plasma and urine decreased significantly in 17 patients who underwent R0 resection, but increased remarkably in 6 patients when recurrence or metastasis occurred (P < 0.05). However, those who underwent R1 or R2 resection in 6 patients kept stable. For 8 patients who received chemotherapy, heparanase mRNA and activity in plasma and urine decreased in each of the samples (P < 0.05). Patients with high heparanase mRNA (≥a cutoff value of 1.84) in PBMC and activity in plasma (≥1.30U/ml) were associated with a poor postoperative survival (P = 0.02 and P = 0.04). CONCLUSIONS: Heparanase mRNA in PBMC and activity in plasma are closely correlated with therapeutic responsiveness and survival time, indicating that heparanase level in blood might be a sensitive but non-specific marker to monitor patients' response to anticancer treatment and to predict survival.

Tafazzin mediates tamoxifen resistance by regulating cellular phospholipid composition in ER-positive breast cancer.

Tamoxifen is the frontline therapeutic agent for the estrogen receptor-positive (ER + ) subtype of breast cancer patients, which accounts for 70-80% of total breast cancer incidents. However, clinical resistance to tamoxifen has become increasingly common, highlighting the need to identify the underlying cellular mechanisms. In our study, we employed a genome-scale CRISPR-Cas9 loss-of-function screen and validation experiments to discover that Tafazzin (TAZ), a mitochondrial transacylase, is crucial for maintaining the cellular sensitivity of ER+ breast cancer cells to tamoxifen and other chemotherapies. Mechanistically, we found that cardiolipin, whose synthesis and maturation rely on TAZ, is required to maintain cellular sensitivity to tamoxifen. Loss of metabolic enzymatic activity of TAZ causes ERα downregulation and therapy resistance. Interestingly, we observed that TAZ deficiency also led to the upregulation of lysophosphatidylcholine (LPC), which in turn suppressed ERα expression and nuclear localization, thereby contributing to tamoxifen resistance. LPC is further metabolized to lysophosphatidic acid (LPA), a bioactive molecule that supports cell survival. Thus, our findings suggest that the depletion of TAZ promotes tamoxifen resistance through an LPC-LPA phospholipid synthesis axis, and targeting this lipid metabolic pathway could restore cell susceptibility to tamoxifen treatment.

Osteoclast Cancer Cell Metabolic Cross-talk Confers PARP Inhibitor Resistance in Bone Metastatic Breast Cancer.

The majority of patients with late-stage breast cancer develop distal bone metastases. The bone microenvironment can affect response to therapy, and uncovering the underlying mechanisms could help identify improved strategies for treating bone metastatic breast cancer. Here, we observed that osteoclasts reduced the sensitivity of breast cancer cells to DNA damaging agents, including cisplatin and the PARP inhibitor (PARPi) olaparib. Metabolic profiling identified elevated glutamine production by osteoclasts. Glutamine supplementation enhanced the survival of breast cancer cells treated with DNA damaging agents, while blocking glutamine uptake increased sensitivity and suppressed bone metastasis. GPX4, the critical enzyme responsible for glutathione oxidation, was upregulated in cancer cells following PARPi treatment through stress-induced ATF4-dependent transcriptional programming. Increased glutamine uptake and GPX4 upregulation concertedly enhanced glutathione metabolism in cancer cells to help neutralize oxidative stress and generate PARPi resistance. Analysis of paired patient samples of primary breast tumors and bone metastases revealed significant induction of GPX4 in bone metastases. Combination therapy utilizing PARPi and zoledronate, which blocks osteoclast activity and thereby reduces the microenvironmental glutamine supply, generated a synergistic effect in reducing bone metastasis. These results identify a role for glutamine production by bone-resident cells in supporting metastatic cancer cells to overcome oxidative stress and develop resistance to DNA-damaging therapies. SIGNIFICANCE: Metabolic interaction between osteoclasts and tumor cells contributes to resistance to DNA-damaging agents, which can be blocked by combination treatment with PARP and osteoclast inhibitors to reduce bone metastatic burden.

Effect of healthy tissue ablation surrounding VX2 rabbit liver tumors by high-intensity focused ultrasound combined with an ultrasound contrast agent.

OBJECTIVES: The purpose of this study was to determine the minimum amount of healthy peripheral tissue that should be ablated when treating VX2 liver tumors with high-intensity focused ultrasound combined with an ultrasound contrast agent. METHODS: Fifty-one rabbits with hepatic tumors were established and randomly divided into the following groups: group A, which only had their tumors ablated; group B, which had their tumors and 2 mm of healthy adjacent tissue ablated; and group C, which had their tumors and 4 mm of healthy adjacent tissue ablated. The pathologic characteristics of the target tissue, serum alanine aminotransferase (ALT) level, presence of intrahepatic and distant metastases, and survival time between different groups were compared after high-intensity focused ultrasound treatment. RESULTS: After ablation, coagulative necrosis was observed in all targeted tissue. The serum ALT level in group C was the highest and the level in group A was the lowest on the third and fifth days after ablation (P < .05), respectively. Fourteen days later, the serum ALT level in groups B and C decreased to normal, whereas the level in group A was abnormal and significantly higher (P < .05). Compared with group A, the prevalence of metastases in groups B and C was significantly lower (P < .05), and the survival time was significantly longer (P < .05); there appeared to be no statistically significant difference between groups B and C (P > .05). CONCLUSIONS: Ablation of a tumor along with 2 mm of healthy surrounding tissue is a more effective strategy for treating hepatic cancer with high-intensity focused ultrasound coupled with an ultrasound contrast agent.

In vitro and in vivo assessment of biocompatibility of AZ31 alloy as biliary stents: a preclinical approach.

INTRODUCTION: Biomaterial technology due to its lack of or minimal side effects in tissues has great potential. Traditionally biomaterials used were cobalt-chromium, stainless steel and nitinol alloys. Biomaterials such as magnesium (Mg) and zinc (Zn) have good biocompatibility and consequently can be a potential material for medical implants. To date, the effects of AZ31 alloy stent on cell apoptosis are still unclear. The current investigation was designed to determine the effect of AZ31 alloy stent on necrosis and apoptosis of common bile duct (CBD) epithelial cells. MATERIAL AND METHODS: We experimented with application of different concentrations of AZ31 alloy stent to primary mouse extrahepatic bile epithelial cells (MEBECs) and estimated the effect on apoptosis and necrotic cells. Apoptosis and pro-apoptosis expression were estimated through real-time PCR. For in vivo protocol, we used rabbits, implanted the AZ31 bile stent, and estimated its effect on the CBD. AZ31 (40%) concentration showed an effect on the apoptotic and necrotic cells. RESULTS: Real-time PCR revealed that AZ31 (40%) concentration increased the apoptotic genes such as NF-κB, caspase-3, Bax and Bax/Bcl-2 ratio as compared to the control group. In the in vivo experiment, AZ31 alloy stents were implanted into the CBD and showed an effect on the alteration the hematological, hepatic and non-hepatic parameters. CONCLUSIONS: To conclude, it can be stated that AZ31 induces apoptosis via alteration in genes including nuclear factor kappa-B (NF-κB), caspase-3, Bax and Bax/Bcl-2 ratio and improved the hematological, hepatic and non-hepatic parameters.

LOXL2 upregulates hypoxia­inducible factor­1α signaling through Snail­FBP1 axis in hepatocellular carcinoma cells.

Lysyl oxidase­like 2 (LOXL2), a member of the lysyl oxidase gene family, is involved in the progression of hepatocellular carcinoma progression and metastasis. Increased expression of LOXL2 has been identified in several types of cancer, including hepatocellular carcinoma. Recently, LOXL2 has been reported to promote epithelial­mesenchymal transition by reducing E­cadherin expression via the upregulation of Snail expression. The present study provided evidence demonstrating that LOXL2 inhibited the expression of fructose­1, 6­biphosphatase (FBP1) and enhanced the glycolysis of Huh7 and Hep3B hepatocellular carcinoma cell lines in a Snail­dependent manner. Overexpression of the point­mutated form of LOXL2 [LOXL2(Y689F)], which lacks enzymatic activity, does not affect the expression of Snail1 or FBP1. Notably, targeting extracellular LOXL2 of Huh7 cells with a therapeutic antibody was unable to abolish its regulation on the expression of Snail and FBP1. Knockdown of LOXL2 also interrupted the angiogenesis of Huh7 and Hep3B cells, and this effect could be rescued by the overexpression of Snail. Furthermore, upregulation of hypoxia­inducible factor 1α (HIF­1α) and vascular endothelial growth factor (VEGF) expression was observed in Huh7 and Hep3B cells expressing wild­type LOXL2. Notably, the selective LOXL2 inhibitor LOXL2­IN­1 could upregulate the expression of FBP1 and inhibit the expression of Snail, HIF­1α and VEGF in HCC cells, but not in FBP1­knockdown cells. The results of the present study indicated that the intracellular activity of LOXL2 upregulated HIF­1α/VEGF signaling pathways via the Snail­FBP1 axis, and this phenomenon could be inhibited by LOXL2 inhibition. Collectively, these findings further support that LOXL2 exhibits an important role in the progression of hepatocellular carcinoma and implicates LOXL2 as a potential therapeutic agent for the treatment of this disease.

Increased vessel perfusion predicts the efficacy of immune checkpoint blockade.

Immune checkpoint blockade (ICB) has demonstrated curative potential in several types of cancer, but only for a small number of patients. Thus, the identification of reliable and noninvasive biomarkers for predicting ICB responsiveness is an urgent unmet need. Here, we show that ICB increased tumor vessel perfusion in treatment-sensitive EO771 and MMTV-PyVT breast tumor as well as CT26 and MCA38 colon tumor models, but not in treatment-resistant MCaP0008 and 4T1 breast tumor models. In the sensitive tumor models, the ability of anti-cytotoxic T lymphocyte-associated protein 4 or anti-programmed cell death 1 therapy to increase vessel perfusion strongly correlated with its antitumor efficacy. Moreover, globally enhanced tumor vessel perfusion could be detected by Doppler ultrasonography before changes in tumor size, which predicted final therapeutic efficacy with more than 90% sensitivity and specificity. Mechanistically, CD8+ T cell depletion, IFN-γ neutralization, or implantation of tumors in IFN-γ receptor knockout mice abrogated the vessel perfusion enhancement and antitumor effects of ICB. These results demonstrated that ICB increased vessel perfusion by promoting CD8+ T cell accumulation and IFN-γ production, indicating that increased vessel perfusion reflects the successful activation of antitumor T cell immunity by ICB. Our findings suggest that vessel perfusion can be used as a novel noninvasive indicator for predicting ICB responsiveness.

Effects of modified splenocaval shunt plus devascularization on esophagogastric variceal bleeding: a comparative study of this treatment and devascularization only in cirrhotic portal hypertension.

BACKGROUND: Pericardial devascularization (PCDV) and portosystemic shunt were reported to have favorable results for the management of portal hypertension in cirrhotic patients in China and the West, respectively. This study was undertaken to investigate the effects of a modified proximal splenocaval shunt plus PCDV on variceal bleeding in patients with portal hypertension. METHODS: From January 1997 to December 2007, 168 patients with portal hypertension of cirrhotic origin received an operation for gastroesophageal variceal bleeding. Of these, 90 patients received a splenocaval shunt plus a PCDV procedure (Combined Group) and the other 78 patients received a PCDV procedure only (PCDV Group). The procedure-related morbidity and mortality, rebleeding, encephalopathy, and survival rates were analyzed. RESULTS: Postoperative mortality was 3.3% in the combined group and 5.1% in the PCDV group (P > 0.05). Overall morbidity was 13.3% in the combined group and 15.4% in the PCDV group (P > 0.05). The rate for rebleeding, including variceal bleeding and gastropathy, was 5.1% in the combined group, which was significantly lower than that in the PCDV group, at 16.7% (P < 0.05). The incidence of encephalopathy was 6.63% in the combined group and 6.67% in the PCDV group (P > 0.05). The 1-, 3-, 5- and 10-year survival rates were 97.4, 91.7, 80.0, and 60.0% in the combined group and 96.7, 83.3, 73.3, and 53.3% in the PCDV group (P > 0.05). CONCLUSIONS: The modified splenocaval shunt plus PCDV is a safe and effective procedure for the long-term control of variceal bleeding; the procedure may not only maintain the portal flow to the liver, but may also protect the liver function in cirrhotic patients. The better clinical outcome means that the procedure may be one of the best choices for treating portal hypertension of cirrhotic origin.