RANK/RANKL axis promotes migration, invasion, and metastasis of osteosarcoma via activating NF-κB pathway.

Osteosarcoma (OS) is one of the most prevalent primary bone tumors with a high degree of metastasis and poor prognosis. Epithelial-to-mesenchymal transition (EMT) is a cellular mechanism that contributes to the invasion and metastasis of cancer cells, and OS cells have been reported to exhibit EMT-like characteristics. Our previous studies have shown that the interaction between tumor necrosis factor superfamily member 11 (TNFRSF11A; also known as RANK) and its ligand TNFSF11 (also known as RANKL) promotes the EMT process in breast cancer cells. However, whether the interaction between RANK and RANKL enhances aggressive behavior by inducing EMT in OS cells has not yet been elucidated. In this study, we showed that the interaction between RANK and RANKL increased the migration, invasion, and metastasis of OS cells by promoting EMT. Importantly, we clarified that the RANK/RANKL axis induces EMT by activating the nuclear factor-kappa B (NF-κB) pathway. Furthermore, the NF-κB inhibitor dimethyl fumarate (DMF) suppressed migration, invasion, and EMT in OS cells. Our results suggest that the RANK/RANKL axis may serve as a potential tumor marker and promising therapeutic target for OS metastasis. Furthermore, DMF may have clinical applications in the treatment of lung metastasis in patients with OS.

Statins enhances antitumor effect of oxaliplatin in KRAS-mutated colorectal cancer cells and inhibits oxaliplatin-induced neuropathy.

BACKGROUND: KRAS mutations are fraught with the progression of colorectal cancer and resistance to chemotherapy. There are pathways such as extracellular regulated protein kinase 1/2 (ERK1/2) and Akt downstream and farnesylation and geranylgeranylation upstream that are activated upon mutated KRAS. Previous studies have shown that statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, are effective to treat KRAS mutated colorectal cancer cells. Increased doses of oxaliplatin (L-OHP), a well-known alkylating chemotherapeutic drug, causes side effects such as peripheral neuropathy due to ERK1/2 activation in spinal cords. Hence, we examined the combinatorial therapeutic efficacy of statins and L-OHP to reduce colorectal cancer cell growth and abrogate neuropathy in mice. METHODS: Cell survival and confirmed apoptosis was assessed using WST-8 assay and Annexin V detection kit. Detection of phosphorylated and total proteins was analyzed the western blotting. Combined effect of simvastatin and L-OHP was examined the allograft mouse model and L-OHP-induced neuropathy was assessed using cold plate and von Frey filament test. RESULTS: In this study, we examined the effect of combining statins with L-OHP on induction of cell death in colorectal cancer cell lines and improvement of L-OHP-induced neuropathy in vivo. We demonstrated that combined administration with statins and L-OHP significantly induced apoptosis and elevated the sensitivity of KRAS-mutated colorectal cancer cells to L-OHP. In addition, simvastatin suppressed KRAS prenylation, thereby enhancing antitumor effect of L-OHP through downregulation of survivin, XIAP, Bcl-xL, and Bcl-2, and upregulation of p53 and PUMA via inhibition of nuclear factor of κB (NF-κB) and Akt activation, and induction of c-Jun N-terminal kinase (JNK) activation in KRAS-mutated colorectal cancer cells. Moreover, simvastatin enhanced the antitumor effects of L-OHP and suppressed L-OHP-induced neuropathy via ERK1/2 activation in vivo. CONCLUSION: Therefore, statins may be therapeutically useful as adjuvants to L-OHP in KRAS-mutated colorectal cancer and may also be useful in the treatment of L-OHP-induced neuropathy.

Efficacy of palliative surgery for gastric cancer patients with peritoneal metastasis who still have residual peritoneal dissemination after chemotherapy.

PURPOSE: Gastric cancer patients with peritoneal metastasis (PM) are generally treated with systemic chemotherapy. When PM has disappeared because of chemotherapy, radical gastrectomy (so-called conversion surgery) is usually performed. We have previously reported the efficacy of conversion surgery, but there are no reports examining the efficacy of palliative gastrectomy for patients with residual PM after chemotherapy. The purpose of this study was to investigate the efficacy of palliative surgery for gastric cancer patients with PM who still have residual peritoneal dissemination after chemotherapy. METHODS: Twenty-five gastric cancer patients with PM confirmed by laparoscopy and who had received chemotherapy but who still had residual PM were included in this study. Among the 25 patients, palliative surgery was performed in 20 patients (PS group) and chemotherapy was continued in 5 patients (CTx group), and their therapeutic outcomes were compared. RESULTS: In the PS group, total and distal gastrectomies were performed. Clavien-Dindo grade I postoperative complications occurred in two patients (10%). There were no treatment-related deaths. Postoperative chemotherapy was performed all cases. In the PS group, the median survival time (MST) reached 22.5 months, with 1- and 2-year overall survival (OS) rates of 95% and 45%, respectively, whereas in the CTx group, the MST was 15.8 months, and the 1- and 2-year OS rates were 60% and 0%, respectively. The PS group had significantly longer OS than the CTx group (P=0.044). CONCLUSIONS: Palliative surgery is safe and may prolong survival in gastric cancer patients with residual PM after chemotherapy.

Efficacy of conversion surgery after a single intraperitoneal administration of paclitaxel and systemic chemotherapy for gastric cancer with peritoneal metastasis.

PURPOSE: The prognosis of gastric cancer patients with peritoneal metastasis (PM) remains dismal with standard systemic chemotherapy. Intraperitoneal (i.p.) chemotherapy with paclitaxel (PTX) has local effects on intra-abdominal cancer cells. According to this phenomenon, we have developed regimens combining single i.p. PTX administration with systemic chemotherapy. This treatment strategy is very promising; however, the effect of "conversion surgery" in patients responding to this chemotherapy is unclear. Therefore, we performed a retrospective study to evaluate the safety and efficacy of conversion surgery for gastric cancer patients with PM. METHODS: We enrolled 52 gastric cancer patients with PM who were treated with single i.p. PTX plus systemic chemotherapy between 2005 and 2015. Conversion surgery was performed where PM was eliminated by combination chemotherapy. RESULTS: Among 52 gastric cancer patients, the disappearance of PM was confirmed in 33 patients (63.5%). Gastrectomy with D2 lymph node dissection was performed in all these patients. Histological response of grade ≥ 1b was achieved in 13 patients (39%). Clavien-Dindo grade II postoperative complications occurred in three patients (9%). There were no treatment-related deaths. The median survival time and 1-, 3-, and 5-year overall survival rates of the 33 patients who underwent conversion surgery were 30.7 months and 78.8%, 36.3%, and 24.2%, respectively, and those of the 19 patients who did not undergo surgery were 12.5 months and 52.6%, 5.2%, and 0%, respectively. CONCLUSION: Conversion surgery is safe and may prolong survival for gastric cancer patients with PM who have responded to single i.p. PTX plus systemic chemotherapy.

Dimethyl Fumarate Induces Apoptosis via Inhibition of NF-κB and Enhances the Effect of Paclitaxel and Adriamycin in Human TNBC Cells.

Triple-negative breast cancer (TNBC) has the poorest prognosis of all breast cancer subtypes. Recently, the activation of NF-κB, which is involved in the growth and survival of malignant tumors, has been demonstrated in TNBC, suggesting that NF-κB may serve as a new therapeutic target. In the present study, we examined whether dimethyl fumarate (DMF), an NF-κB inhibitor, induces apoptosis in TNBC cells and enhances the apoptosis-inducing effect of paclitaxel and adriamycin. Cell survival was analyzed by the trypan blue assay and apoptosis assay. Protein detection was examined by immunoblotting. The activation of NF-κB p65 was correlated with poor prognosis in patients with TNBC. DMF induced apoptosis in MDA-MB-231 and BT-549 cells at concentrations that were non-cytotoxic to the normal mammary cell line MCF-10A. Furthermore, DMF inhibited NF-κB nuclear translocation and Survivin, XIAP, Bcl-xL, and Bcl-2 expression in MDA-MB-231 and BT-549 cells. Moreover, DMF enhanced the apoptosis-inducing effect of paclitaxel and adriamycin in MDA-MB-231 cells. These findings suggest that DMF may be an effective therapeutic agent for the treatment of TNBC, in which NF-κB is constitutively active. DMF may also be useful as an adjuvant therapy to conventional anticancer drugs.

[Efficacy of a Dexamethasone Dose Escalation Regimen with a Cumulative Dose for Preventing Oxaliplatin Hypersensitivity Reactions].

Oxaliplatin is a platinum complex antineoplastic agent widely used for chemotherapy of colorectal cancer. However, one of its side effects is hypersensitivity reactions, the incidence of which increases with a cumulative dose, thereby posing a difficulty to continue oxaliplatin use. Our hospital changed the premedication of oxaliplatin in August 2009 and September 2012. We retrospectively investigated the usefulness of these premedication changes. The results showed no significant difference in the incidence of hypersensitivity between the control group(12.1%)and the group receiving H1 and H2-blockers (12.3%); however, the incidence of hypersensitivity was significantly reduced in the group receiving increased dexamethasone based on the number of courses(2.7%). Therefore, our regimen was found to be effective in preventing hypersensitivity reactions to oxaliplatin.

[Administration Period of Olanzapine as an Antiemetic Drug for Patients on FEC Therapy-A Survey].

Olanzapine(OLZ)is a multi-acting receptor-targeted antipsychotic drug approved in Japan in December 2017 for the treatment of anticancer drug-induced nausea and vomiting. However, the recommended doses and administration periods of OLZ in the literature and guidelines are varied. Reports on the efficacy and safety of OLZ combined with perioperative chemotherapy for breast cancer in Japanese patients are few. Moreover, the risk of nausea and vomiting during treatment with anticancer drugs in young and women patients remains to be high. In this study, we conducted an exploratory survey on the optimal duration of OLZ administration(days 1-4: 5 mg, before sleep)during perioperative breast cancer 5-fluorouracil, epirubicin, cyclophosphamide(FEC)therapy. We found that treatment with OLZ showed efficacy in improving nausea grade and maintaining relative dose intensity. Moreover, it could be used safely without interruption due to side effects, such as weight gain, elevation in blood glucose, somnolence, and insomnia. Prophylactic antiemetic therapy with OLZ administration (days 1-4: 5 mg)prior to sleep was effective in patients having FEC therapy-induced nausea and vomiting.

Interleukin 19 suppresses RANKL-induced osteoclastogenesis via the inhibition of NF-κB and p38MAPK activation and c-Fos expression in RAW264.7 cells.

Interleukin 19 (IL-19) is a member of the IL-10 family of cytokines and is known as an inhibitory cytokine. IL-10, also an inhibitory cytokine, suppresses the receptor activator of nuclear factor κB (NF-κB) ligand (RANKL)-induced osteoclast differentiation. However, the effects of IL-19 on osteoclast differentiation are not currently well-understood. In this study, we examined whether IL-19 suppresses osteoclast differentiation in the mouse macrophage-like cell line RAW264.7. We found that IL-19 inhibited RANKL-induced osteoclast differentiation. In addition, IL-19 suppressed RANKL-induced NF-κB and p38 mitogen-activated protein kinase (p38MAPK) activation and c-Fos expression. Moreover, RANKL inhibited IL-19 mRNA expression and secretion in RAW264.7 cells, and the inhibition of the IL-19 function promoted osteoclast differentiation. These results indicate that IL-19 suppressed osteoclast differentiation via the inhibition of NF-κB and p38MAPK activation and c-Fos expression. Furthermore, IL-19 may maintain the osteoclast precursor state, such as monocytes and macrophages. These findings may be useful in the development of osteoclast inhibitors, thereby improving treatments for osteoclast activation-related diseases, such as osteoporosis.

The HGF/Met/NF-κB Pathway Regulates RANKL Expression in Osteoblasts and Bone Marrow Stromal Cells.

Multiple myeloma (MM)-induced bone disease occurs through hyperactivation of osteoclasts by several factors secreted by MM cells. MM cell-secreted factors induce osteoclast differentiation and activation via direct and indirect actions including enhanced expression of receptor activator of nuclear factor κB ligand (RANKL) in osteoblasts and bone marrow stromal cells (BMSCs). Hepatocyte growth factor (HGF) is elevated in MM patients and is associated with MM-induced bone disease, although the mechanism by which HGF promotes bone disease remains unclear. In the present study, we demonstrated that HGF induces RANKL expression in osteoblasts and BMSCs, and investigated the mechanism of induction. We found that HGF and MM cell supernatants induced RANKL expression in ST2 cells, MC3T3-E1 cells, and mouse BMSCs. In addition, HGF increased phosphorylation of Met and nuclear factor κB (NF-κB) in ST2 cells, MC3T3-E1 cells, or mouse BMSCs. Moreover, Met and NF-κB inhibitors suppressed HGF-induced RANKL expression in ST2 cells, MC3T3-E1 cells, and mouse BMSCs. These results indicated that HGF promotes RANKL expression in osteoblasts and BMSCs via the Met/NF-κB signaling pathway, and Met and NF-κB inhibitors suppressed HGF-induced RANKL expression. Our findings suggest that Met and NF-κB inhibitors are potentially useful in mitigating MM-induced bone disease in patients expressing high levels of HGF.

[Three Cases of Augmented Chemotherapy-Induced Peripheral Neuropathy after Changing from mFOLFOX6 to FOLFIRI Therapy in Patients with Colorectal Cancer].

We had cases in which peripheral neuropathy was augmented after changing from mFOLFOX6, a chemotherapy for colorectal cancer, to FOLFIRI and comparatively examined disease status and trends. There were no shared points with respect to patient characteristics, timing of peripheral neuropathy augmentation, drug dosage, etc. It appeared that the change in chemotherapy itself had an effect on neuropathic symptoms. Regarding the change in chemotherapy, the therapeutic agent was switched from oxaliplatin to irinotecan; the cause was unknown, but some effects of these two drugs were suggested. Future investigation, including the examination of genetic mutations, is necessary.

Combination therapy with dacarbazine and statins improved the survival rate in mice with metastatic melanoma.

Malignant melanoma is a highly aggressive skin cancer, and the overall median survival in patients with metastatic melanoma is only 6-9 months. Although molecular targeted therapies have recently been developed and have improved the overall survival, melanoma patients may show no response and acquisition of resistance to these drugs. Thus, other molecular approaches are essential for the treatment of metastatic melanoma. In the present study, we investigated the effect of cotreatment with dacarbazine and statins on tumor growth, metastasis, and survival rate in mice with metastatic melanomas. We found that cotreatment with dacarbazine and statins significantly inhibited tumor growth and metastasis via suppression of the RhoA/RhoC/LIM domain kinase/serum response factor/c-Fos pathway and enhanced p53, p21, p27, cleaved caspase-3, and cleaved poly(ADP-ribose) polymerase 1 expression in vivo. Moreover, the cotreatment significantly improved the survival rate in metastasis-bearing mice. Importantly, treatment with dacarbazine plus 100 mg/kg simvastatin or fluvastatin prevented metastasis-associated death in 4/20 mice that received dacarbazine + simvastatin and in 8/20 mice that received dacarbazine + fluvastatin (survival rates, 20% and 40%, respectively). These results suggested that cotreatment with dacarbazine and statins may thus serve as a new therapeutic approach to control tumor growth and metastasis in melanoma patients.

Overexpression of HIF-1α contributes to melphalan resistance in multiple myeloma cells by activation of ERK1/2, Akt, and NF-κB.

Multiple myeloma (MM) commonly displays multidrug resistance and is associated with poor prognosis. Therefore, it is important to identify the mechanisms by which MM cells develop multidrug resistance. Our previous study showed that multidrug resistance is correlated with overexpression of multidrug resistance protein 1 (MDR1) and Survivin, and downregulation of Bim expression in melphalan-resistant RPMI8226/L-PAM cells; however, the underlying mechanism of multidrug resistance remains unclear. In the present study, we investigated the mechanism of multidrug resistance in melphalan-resistant cells. We found that RPMI8226/L-PAM and ARH-77/L-PAM cells showed increased phosphorylation of extracellular signal-regulated protein kinase 1/2 (ERK1/2) and Akt, and nuclear localization of nuclear factor κB (NF-κB). The combination of ERK1/2, Akt, and NF-κB inhibitors with melphalan reversed melphalan resistance via suppression of Survivin expression and enhanced Bim expression in melphalan-resistant cells. In addition, RPMI8226/L-PAM and ARH-77/L-PAM cells overexpressed hypoxia-inducible factor 1α (HIF-1α) via activation of ERK1/2, Akt, and NF-κB. Moreover, suppression of HIF-1α by echinomycin or HIF-1α siRNA resensitized RPMI8226/L-PAM cells to melphalan through downregulation of Survivin expression and upregulation of Bim expression. These results indicate that enhanced Survivin expression and decreased Bim expression by HIF-1α via activation of ERK1/2, Akt, and NF-κB play a critical role in melphalan resistance. Our findings suggest that HIF-1α, ERK1/2, Akt, and NF-κB inhibitors are potentially useful as anti-MDR agents for the treatment of melphalan-resistant MM.

Phase II trial of neoadjuvant chemotherapy with intraperitoneal paclitaxel, S-1, and intravenous cisplatin and paclitaxel for stage IIIA or IIIB gastric cancer.

BACKGROUND: We carried out a phase II trial to evaluate the feasibility and efficacy of neoadjuvant chemotherapy comprising a single intraperitoneal administration of paclitaxel, followed by intravenous administrations of paclitaxel and cisplatin with S-1 for clinical stage III gastric cancer. METHODS: Patients with potentially resectable gastric cancer were eligible. A laparoscopic survey was performed to confirm CY0 and P0. Intraperitoneal paclitaxel (60 mg/m 2 ) was administered, followed by systemic chemotherapy. Surgery was performed after two cycles of chemotherapy. The primary endpoint was the response rate of chemotherapy. Secondary endpoints were adverse events, pathological response rate, and overall survival rate. RESULTS: Twenty patients were enrolled. Planned cycles were completed in all patients. Grade 3/4 leukopenia and grade 3/4 neutropenia were observed in four (20%) and seven (35%) patients, respectively. The overall response rate was 70% (partial response: 14, stable disease: 5, progressive disease: 1). All patients underwent R0 gastrectomy with D2 lymph-node dissection, with no surgery-related deaths. The pathological response rate was 65% (13 of 20). The 3- and 5-year overall survival rates were 90.0% and 77.1%, respectively. CONCLUSIONS: Neoadjuvant chemotherapy including intraperitoneal paclitaxel followed by sequential intravenous paclitaxel and cisplatin with S-1 for resectable advanced gastric cancer is feasible and effective.

Pioglitazone inhibits cancer cell growth through STAT3 inhibition and enhanced AIF expression via a PPARγ-independent pathway.

Pioglitazone is an anti-diabetic agent that belongs to the thiazolidinedione class, which target peroxisome proliferator-activated receptor γ (PPARγ), a transcription factor in the nuclear receptor family. Different cancer cells expressing high levels of PPARγ and PPARγ ligands induce cell cycle arrest, cell differentiation, and apoptosis. However, the mechanisms underlying these processes remain unknown. Here, we investigated the mechanism underlying pioglitazone-induced apoptosis in human cancer cells. We showed that at similar concentrations, pioglitazone induced death in cancer cells expressing high or low levels of PPARγ. Combined treatment of pioglitazone and GW9662, a PPARγ antagonist, did not rescue this cell death phenotype. Z-VAD-fmk, a pan-caspase inhibitor, did not reverse pioglitazone-induced apoptosis in cancer cells expressing PPARγ at high or low levels. Pioglitazone suppressed the activation of signal transducers and activator of transcription 3 (STAT3) and Survivin expression, and enhanced the apoptosis-inducing factor (AIF) levels in these cells. Furthermore, pioglitazone enhanced the cytotoxic effect of cisplatin and oxaliplatin by suppressing Survivin and increasing AIF expression. These results indicated that pioglitazone induced apoptosis via a PPARγ-independent pathway, thus describing pioglitazone as a potential therapeutic agent for controlling the progression of different cancers.

The MIP-1α autocrine loop contributes to decreased sensitivity to anticancer drugs.

Several autocrine soluble factors, including macrophage inflammatory protein-1α (MIP-1α), tumor necrosis factor-α, and hepatocyte growth factor, promote cell survival and growth in multiple myeloma (MM) cells. We hypothesized that inhibition of the MIP-1α autocrine loop may enhance the cytotoxic effect of anticancer drugs in MM cell lines. In the present study, an MIP-1α neutralizing antibody suppressed cell proliferation and enhanced the cytotoxic effect of melphalan or bortezomib on MM cells. In addition, melphalan resistance cells (RPMI8226/L-PAM and HS-sultan/L-PAM cells) secreted MIP-1α and neutralizing antibody of MIP-1α partially overcame melphalan resistance. Moreover, combination treatment with MIP-1α neutralizing antibody and melphalan or bortezomib inhibited extracellular signal regulated kinase 1/2 (ERK1/2), Akt, and mammalian target of rapamycin (mTOR) activation, Bcl-2, Bcl-xL, and Survivin expression, and upregulated the expression of Bim and cleaved Poly (ADP-ribose) polymerase (PARP). Treatment of IM9 cells with MIP-1α siRNA suppressed the activation of ERK1/2, Akt, and mTOR, and enhanced the cytotoxic effect of melphalan and bortezomib. These results indicate that MIP-1α neutralizing antibodies or MIP-1α siRNA enhance the cytotoxic effect of melphalan and bortezomib by suppressing the chemokine receptor/ERK and chemokine receptor/Akt/mTOR pathways. The inhibition of MIP-1α may thus provide a new therapeutic approach to control tumor progression and bone destruction in patients with MM.

Tamoxifen suppresses paclitaxel-, vincristine-, and bortezomib-induced neuropathy via inhibition of the protein kinase C/extracellular signal-regulated kinase pathway.

Chemotherapy-induced neuropathy is a highly problematic, dose-limiting effect of potentially curative regimens of cancer chemotherapy. When neuropathic pain is severe, patients often either switch to less-effective chemotherapy agents or choose to discontinue chemotherapy entirely. Conventional chemotherapy drugs used to treat lung and breast cancer, multiple myeloma, and lymphoma include paclitaxel, vincristine, and bortezomib. Approximately 68% of patients receiving these anticancer drugs develop neuropathy within the first month of treatment, and while strategies to prevent chemotherapy-induced neuropathy have been investigated, none have yet been proven as effective. Recent reports suggest that chemotherapy-induced neuropathy is associated with signal transduction molecules, including protein kinase C and mitogen-activated protein kinases. It is currently unclear whether protein kinase C inhibition can prevent chemotherapy-induced neuropathy. In this study, we found that tamoxifen, a protein kinase C inhibitor, suppressed paclitaxel-, vincristine-, and bortezomib-induced cold and mechanical allodynia in mice. In addition, chemotherapy drugs induce neuropathy via the protein kinase C/extracellular signal-regulated kinase pathway in the spinal cord in lumbar segments 4-6 and dorsal root ganglions. In addition, tamoxifen was shown to act synergistically with paclitaxel to inhibit tumor-growth in mice injected with tumor cells. Our results indicated that paclitaxel-, vincristine-, and bortezomib-induced neuropathies were associated with the protein kinase C/extracellular signal-regulated kinase pathway in the lumbar spinal cord and dorsal root ganglions, which suggest that protein kinase C inhibitors may be therapeutically effective for the prevention of chemotherapy-induced neuropathy when administered with standard chemotherapy agents.

Statins induce apoptosis through inhibition of Ras signaling pathways and enhancement of Bim and p27 expression in human hematopoietic tumor cells.

Recently, statins have been demonstrated to improve cancer-related mortality or prognosis in patients of various cancers. However, the details of the apoptosis-inducing mechanisms remain unknown. This study showed that the induction of apoptosis by statins in hematopoietic tumor cells is mediated by mitochondrial apoptotic signaling pathways, which are activated by the suppression of mevalonate or geranylgeranyl pyrophosphate biosynthesis. In addition, statins decreased the levels of phosphorylated extracellular signal-regulated kinase 1/2 and mammalian target of rapamycin through suppressing Ras prenylation. Furthermore, inhibition of extracellular signal-regulated kinase 1/2 and mammalian target of rapamycin by statins induced Bim expression via inhibition of Bim phosphorylation and ubiquitination and cell-cycle arrest at G1 phase via enhancement of p27 expression. Moreover, combined treatment of U0126, a mitogen-activated protein kinase kinase 1/2 inhibitor, and rapamycin, a mammalian target of rapamycin inhibitor, induced Bim and p27 expressions. The present results suggested that statins induce apoptosis by decreasing the mitochondrial transmembrane potential, increasing the activation of caspase-9 and caspase-3, enhancing Bim expression, and inducing cell-cycle arrest at G1 phase through inhibition of Ras/extracellular signal-regulated kinase and Ras/mammalian target of rapamycin pathways. Therefore, our findings support the use of statins as potential anticancer agents or concomitant drugs of adjuvant therapy.

The sensitivity of head and neck carcinoma cells to statins is related to the expression of their Ras expression status, and statin-induced apoptosis is mediated via suppression of the Ras/ERK and Ras/mTOR pathways.

Statins induce apoptosis of tumour cells by inhibiting the prenylation of small G-proteins. However, the details of the apoptosis-inducing mechanisms remain poorly understood. The present study showed that the induction of apoptosis by statins in four different human head and neck squamous cell carcinoma (HNSCC) cell lines, HSC-3, HEp-2, Ca9-22, and SAS cells was mediated by increased caspase-3 activity. Statins induced apoptosis by the suppression of geranylgeranyl pyrophosphate biosynthesis. Furthermore, statins decreased the levels of phosphorylated ERK and mTOR by inhibiting the membrane localization of Ras and enhancing Bim expression in HSC-3 and HEp-2 cells. We also found that in all the cell types analyzed, the IC50 values for fluvastatin and simvastatin were highest in HEp-2 cells. In addition, HSC-3, Ca9-22, and SAS cells had higher Ras expression and membrane localization, higher activation of ERK1/2 and mTOR, and lower levels of Bim expression than HEp-2 cells. Our results indicate that statins induce apoptosis by increasing the activation of caspase-3 and by enhancing Bim expression through inhibition of the Ras/ERK and Ras/mTOR pathways. Furthermore, the sensitivity of HNSCC cells to statin treatment was closely related to Ras expression and prenylation levels, indicating that statins may act more effectively against tumours with high Ras expression and Ras-variability. Therefore, our findings support the use of statins as potential anticancer agents.

[Influence of Next-Day Administration of Pegfilgrastim after FEC100 Chemotherapy in Japanese with Breast Cancer on Neutrophil Count].

Febrile neutropenia(FN)is one of the serious treatment-related toxicities after FEC100(5-fluorouracil 500mg/m2, epiru- bicin 100mg/m2, cyclophosphamide 500 mg/m2)chemotherapy for breast cancer. Granulocyte-colony stimulating factor(GCSF) is used as a support therapy for FN. Thus, we evaluated retrospectively the safety of administering pegfilgrastim the day after FEC100 chemotherapy in Japanese patients with breast cancer as compared with lenograstim. Grade 3 or 4 neutropenia was observed in 91.7% patients after pegfilgrastim administration and in 63.2% after lenograstim. The incidence rate of FN was 7.0%after pegfilgrastim administration and 9.7%after lenograstim, a difference that was not significantly different(p= 0.741). The mean relative dose intensity was good at 0.98 for pegfilgrastim and 0.97 for lenograstim. In conclusion, pegfilgrastim is not inferior to lenograstim in the incidence of FN. However, we do not recommend administering pegfilgrastim on the day after FEC100 therapy because it causes more severe neutropenia and has a high risk of FN. The timing of administration of pegfilgrastim in FEC100 therapy requires further study.

Mangiferin, a novel nuclear factor kappa B-inducing kinase inhibitor, suppresses metastasis and tumor growth in a mouse metastatic melanoma model.

Advanced metastatic melanoma, one of the most aggressive malignancies, is currently without reliable therapy. Therefore, new therapies are urgently needed. Mangiferin is a naturally occurring glucosylxanthone and exerts many beneficial biological activities. However, the effect of mangiferin on metastasis and tumor growth of metastatic melanoma remains unclear. In this study, we evaluated the effect of mangiferin on metastasis and tumor growth in a mouse metastatic melanoma model. We found that mangiferin inhibited spontaneous metastasis and tumor growth. Furthermore, mangiferin suppressed the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated NF-κB-inducing kinase (NIK), inhibitor of kappa B kinase (IKK), and inhibitor of kappa B (IκB) and increases the expression of IκB protein in vivo. In addition, we found that mangiferin inhibited the expression of matrix metalloproteinases (MMPs) and very late antigens (VLAs) in vivo. Mangiferin treatment also increased the expression of cleaved caspase-3, cleaved Poly ADP ribose polymerase-1 (PARP-1), p53 upregulated modulator of apoptosis (PUMA), p53, and phosphorylated p53 proteins, and decreased the expression of Survivin and Bcl-associated X (Bcl-xL) proteins in vivo. These results indicate that mangiferin selectivity suppresses the NF-κB pathway via inhibition of NIK activation, thereby inhibiting metastasis and tumor growth. Importantly, the number of reported NIK selective inhibitors is limited. Taken together, our data suggest that mangiferin may be a potential therapeutic agent with a new mechanism of targeting NIK for the treatment of metastatic melanoma.