Significance of timing of therapeutic line on effectiveness of nivolumab for metastatic renal cell carcinoma.

Objectives: This study aimed to clarify the significance of therapeutic timing on the effectiveness of nivolumab for treating metastatic renal cell carcinoma. Marterials and methods: Fifty-eight patients with metastatic renal cell carcinoma treated with nivolumab monotherapy were retrospectively studied. Patients who were treated with nivolumab as second-line therapy were included in the second-line group, while the others were included in the later-line group. The clinicopathological characteristics, effects of nivolumab, and prognoses of these groups were compared. Results: Twenty and thirty-eight patients were included in the second-line and later-line groups, respectively. There were no significant differences in the distribution of International Metastatic Renal Cell Carcinoma Database Consotium risk and other clinicopathological characteristics between the 2 groups. The proportion of patients whose objective best response was progressive disease in the second-line group was significantly lower than that in the later-line group (15% vs. 50%, p = 0.0090). The 50% progression-free survival with nivolumab in the second-line group was significantly better than that in the later-line group (not reached and 5 months, p = 0.0018). Multivariate analysis showed that the second-line setting was an independent predictive factor for better progression-free survival (p = 0.0028, hazard ratio = 0.108). The 50% overall survival after starting nivolumab in the second-line and later-line groups was not reached and 27.8 months, respectively (p = 0.2652). Conclusions: The therapeutic efficacy of nivolumab as second-line therapy is expected to be better than that of later therapy.

Differentiation of Human Adipose-Derived Mesenchymal Stromal/Stem Cells into Insulin-Producing Cells with A Single Tet-Off Lentiviral Vector System.

OBJECTIVE: Human adipose-derived mesenchymal stromal/stem cells (hASC) constitute an attractive source of stem cells for cell-based therapies in regenerative medicine and tissue engineering as they are easy to acquire from lipoaspirate, expansion, and genetic modification ex vivo. The combination of Pdx-1, MafA, and NeuroD1 has been indicated to possess the ability to reprogram various types of cells into insulin-producing cells. The aim of this study is to investigate whether MafA and NeuroD1 would cooperate with Pdx-1 in the differentiation of hASC into insulin-producing cells. MATERIALS AND METHODS: In this experimental study, we generated polycistronic expression vectors expressing Pdx1 and MafA/NeuroD1 with a reporter from a human EF-1α promoter using 2A peptides in a single tet-off lentiviral vector system. Briefly, hASC were transduced with the lentiviral vectors and allowed to differentiate into insulin-producing cells in vitro and in vivo. Thereafter, RNA expression, dithizone staining, and immunofluorescent analysis were conducted. RESULTS: Cleaved transcriptional factors from a single tet-off lentiviral vector were functionally equivalent to their native proteins and strictly regulated by doxycycline (Dox). Insulin gene expression in hASC transduced with Pdx1, Pdx1/ MafA, and Pdx1/NeuroD1 in differentiation medium were successfully increased by 1.89 ± 0.39, 4.81 ± 0.98, 5.51 ± 0.63, respectively, compared to venus-transduced, control hASC. These cells could form dithizone-positive cell clusters in vitro and were found to express insulin in vivo. CONCLUSION: Using our single tet-off lentiviral vector system, Pdx-1 and MafA/NeuroD1 could be simultaneously expressed in the absence of Dox. Further, this system allowed the differentiation of hASC into insulin-producing cells.

Royal Jelly Protects against Epidermal Stress through Upregulation of the NQO1 Expression.

Royal jelly (RJ) is secreted by honeybees and has been used as an apitherapy to obtain healthy skin since ancient times. However, the mechanism of the protective effects of RJ against skin aging and skin diseases caused by skin stress and its components have not been clarified. In this study, we attempted to understand the effect of RJ on epidermal function and observed that NAD(P)H quinone dehydrogenase 1 (NQO1) is significantly induced by RJ in keratinocytes. The expression of NQO1 was also increased in the 3D epidermal skin model. NQO1 is involved in antioxidation and detoxification metabolism, and we found that RJ protects against the epidermal stress caused by UVB and menadione through the upregulation of NQO1. We identified 10-hydroxy-2-decenoic acid (10H2DA), a major fatty acid in RJ, as an active compound in this reaction as it induced the expression of NQO1 and protected the skin against oxidative stress. We demonstrated that the protective effect of RJ against epidermal stress is mediated through the upregulation of NQO1 by 10H2DA.

Erratum: Improved prognosis for elderly patients with metastatic renal cell carcinoma in the era of targeted therapy.

[This corrects the article DOI: 10.3892/mco.2020.2020.].

Prediction of early progression of metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitor.

BACKGROUND: There are various alternative first-line therapeutic options besides tyrosine kinase inhibitors (TKIs) for metastatic renal cell carcinoma (mRCC). To inform therapeutic decision-making for such patients, this study aimed to identify predictive factors for resistance to TKI. MATERIALS AND METHODS: A total of 239 cases of mRCC patients who received first-line TKI therapy were retrospectively studied. Patients with a radiologic diagnosis of progressive disease within 3 months after initiating therapy were classified as primary refractory cases; the others were classified as non-primary refractory cases. The association between primary refractory cases and age, gender, pathology findings, serum c-reactive protein (CRP) level, metastatic organ status, and 6 parameters defined by the International Metastatic Renal Cell Carcinoma Database Consortium were analyzed. RESULTS: Of 239 cases, 32 (13.3%) received a radiologic diagnosis of progressive disease within 3 months after initiating therapy. The rates of sarcomatoid differentiation, hypercalcemia, a serum CRP level of 0.3 mg/dL or higher, presence of liver metastasis, anemia, and time from diagnosis to treatment interval of less than a year were significantly higher in the primary refractory group. Multivariate analysis showed that sarcomatoid differentiation, hypercalcemia, a serum CRP level of 0.3 mg/dL or higher, and liver metastasis were independently associated with primary refractory disease. A risk-stratified model based upon the number of patients with these factors indicated rates of primary refractory disease of 4.0%, 10.1%, and 45.0% for patients with 0, 1, and 2 or more factors, respectively. CONCLUSIONS: Sarcomatoid differentiation, hypercalcemia, an elevated serum CRP level, and presence of liver metastasis were associated with primary refractory disease in mRCC patients receiving first-line TKI therapy. These results provide clinicians with useful information when selecting a first-line therapeutic option for mRCC patients.

Hydrostatic pressure can induce apoptosis of the skin.

We previously showed that high hydrostatic pressure (HHP) treatment at 200 MPa for 10 min induced complete cell death in skin and skin tumors via necrosis. We used this technique to treat a giant congenital melanocytic nevus and reused the inactivated nevus tissue as a dermis autograft. However, skin inactivated by HHP promoted inflammation in a preclinical study using a porcine model. Therefore, in the present study, we explored the pressurization conditions that induce apoptosis of the skin, as apoptotic cells are not believed to promote inflammation, so the engraftment of inactivated skin should be improved. Using a human dermal fibroblast cell line in suspension culture, we found that HHP at 50 MPa for ≥ 36 h completely induced fibroblast cell death via apoptosis based on the morphological changes in transmission electron microscopy, reactive oxygen species elevation, caspase activation and phosphatidylserine membrane translocation. Furthermore, immunohistochemistry with terminal deoxynucleotidyl transferase dUTP nick-end labeling and cleaved caspase-3 showed most cells in the skin inactivated by pressurization to be apoptotic. Consequently, in vivo grafting of apoptosis-induced inactivated skin resulted in successful engraftment and greater dermal cellular density and macrophage infiltration than our existing method. Our finding supports an alternative approach to hydrostatic pressure application.

Impact of the systemic immune-inflammation index for the prediction of prognosis and modification of the risk model in patients with metastatic renal cell carcinoma treated with first-line tyrosine kinase inhibitors.

INTRODUCTION: International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) criteria are the most representative risk model for patients with metastatic renal cell carcinoma (mRCC). However, the intermediate-risk group of IMDC criteria is thought to include patients with different prognoses because many of the patients are classified into the intermediate-risk group. In this study, we investigated the impact of systemic immune-inflammation index (SII), which is calculated based on neutrophil count, platelet count, and lymphocyte count, on predicting the prognosis in patients with mRCC, and its usefulness for re-classification of patients with a more sophisticated risk model. METHODS: From January 2008 to January 2018, 179 mRCC patients with a pretreatment and SII were retrospectively investigated. All patients were classified into either a high-SII group or a low-SII group based on the cutoff value of a SII at 730, as reported in previous studies; the overall survival (OS) rates in each group were compared. RESULTS: The median age was 65 years old. Males and females comprised 145 and 34 cases, respectively. The categories of favorable-, intermediate-, and poor-risk groups in the IMDC model were assessed in 39, 102, and 38 cases, respectively. The median observation period was 24 months. The low-SII and high-SII groups consisted of 73 and 106 cases, respectively. The 50% OS in the high-SII group was 21.4 months, which was significantly worse than that in the low-SII group (49.7 months; p<0.0001). Multivariate analysis showed that a high SII was an independent predictive factor for a worse OS. Next, we constructed a modified IMDC risk model that included the SII instead of a neutrophil count and a platelet count. By using this modified IMDC model, all cases were re-classified into four groups of 33, 52, 81, and 13 cases with 50% OS of 88.8, 45.9, 29.4, and 4.8 months, respectively. CONCLUSIONS: The SII is useful for establishing a more sophisticated prognostic model that can stratify mRCC patients into four groups with different prognoses.

Improved prognosis for elderly patients with metastatic renal cell carcinoma in the era of targeted therapy.

The present study investigated the outcomes of targeted therapy for elderly patients with metastatic renal cell carcinoma (mRCC). A total of 277 patients with mRCC who were treated with tyrosine kinase inhibitor as a first-line therapy from January 2008 to May 2018 were retrospectively investigated by reviewing clinicopathological data. Patients 75 years or older were classified into the older-aged group (n=55) while all others were classified into the younger-aged group (n=222). The preoperative clinicopathological characteristics and the overall survival (OS) rate for these two groups were subsequently compared. The median age in the older- and younger-aged groups was 78 and 63 years (P<0.0001), respectively. A total of 7, 42 and 6 cases in the older-aged group and 46, 118 and 58 cases in the younger-aged group were classified into favorable, intermediate, and poor risk groups, respectively. The rate of patients with cardiovascular diseases (29.1%) and malignant diseases other than RCC (20.0%) was significantly higher in the older-aged group compared with the younger-aged group (6.8%; P<0.0001 and 7.2%; P=0.0042, respectively). There was a significant improvement in the OS rate for patients beginning targeted therapy after 2011 compared with those starting therapy prior to 2010. The 50% OS rate in patients starting targeted therapy before 2010 and after 2011 was, respectively, 17.1 and 38.6 months for the older-aged group (P=0.0066), while there was no significant difference for the younger-aged group (P=0.1441; 50% OS; 35.9 vs. 30.5 months). The results of the present study indicated that the prognosis for older patients has improved since the introduction of targeted therapy.

Exploration of the Pressurization Condition for Killing Human Skin Cells and Skin Tumor Cells by High Hydrostatic Pressure.

High hydrostatic pressure (HHP) is a physical method for inactivating cells or tissues without using chemicals such as detergents. We previously reported that HHP at 200 MPa for 10 min was able to inactivate all cells in skin and giant congenital melanocytic nevus (GCMN) without damaging the extracellular matrix. We also reported that HHP at 150 MPa for 10 min was not sufficient to inactivate them completely, while HHP at 200 MPa for 10 min was able to inactivate them completely. We intend to apply HHP to treat malignant skin tumor as the next step; however, the conditions necessary to kill each kind of cell have not been explored. In this work, we have performed a detailed experimental study on the critical pressure and pressurization time using five kinds of human skin cells and skin tumor cells, including keratinocytes (HEKas), dermal fibroblasts (HDFas), adipose tissue-derived stem cells (ASCs), epidermal melanocytes (HEMa-LPs), and malignant melanoma cells (MMs), using pressures between 150 and 200 MPa. We pressurized cells at 150, 160, 170, 180, or 190 MPa for 1 s, 2 min, and 10 min and evaluated the cellular activity using live/dead staining and proliferation assays. The proliferation assay revealed that HEKas were inactivated at a pressure higher than 150 MPa and a time period longer than 2 min, HDFas and MMs were inactivated at a pressure higher than 160 MPa and for 10 min, and ASCs and HEMa-LPs were inactivated at a pressure higher than 150 MPa and for 10 min. However, some HEMa-LPs were observed alive after HHP at 170 MPa for 10 min, so we concluded that HHP at a pressure higher than 180 MPa for 10 min was able to inactivate five kinds of cells completely.

Adipose-derived stromal/stem cells improve epidermal homeostasis.

Wound healing is regulated by complex interactions between the keratinocytes and other cell types including fibroblasts. Recently, adipose-derived mesenchymal stromal/stem cells (ASCs) have been reported to influence wound healing positively via paracrine involvement. However, their roles in keratinocytes are still obscure. Therefore, investigation of the precise effects of ASCs on keratinocytes in an in vitro culture system is required. Our recent data indicate that the epidermal equivalents became thicker on a collagen vitrigel membrane co-cultured with human ASCs (hASCs). Co-culturing the human primary epidermal keratinocytes (HPEK) with hASCs on a collagen vitrigel membrane enhanced their abilities for cell proliferation and adhesion to the membrane but suppressed their differentiation suggesting that hASCs could maintain the undifferentiated status of HPEK. Contrarily, the effects of co-culture using polyethylene terephthalate or polycarbonate membranes for HPEK were completely opposite. These differences may depend on the protein permeability and/or structure of the membrane. Taken together, our data demonstrate that hASCs could be used as a substitute for fibroblasts in skin wound repair, aesthetic medicine, or tissue engineering. It is also important to note that a co-culture system using the collagen vitrigel membrane allows better understanding of the interactions between the keratinocytes and ASCs.

Role of FBXW7 in the quiescence of gefitinib-resistant lung cancer stem cells in EGFR-mutant non-small cell lung cancer.

Several recent studies suggest that cancer stem cells (CSCs) are involved in intrinsic resistance to cancer treatment. Maintenance of quiescence is crucial for establishing resistance of CSCs to cancer therapeutics. F-box/WD repeat-containing protein 7 (FBXW7) is a ubiquitin ligase that regulates quiescence by targeting the c-MYC protein for ubiquitination. We previously reported that gefitinib-resistant persisters (GRPs) in EGFR-mutant non-small cell lung cancer (NSCLC) cells highly expressed octamer-binding transcription factor 4 (Oct-4) as well as the lung CSC marker CD133, and they exhibited distinctive features of the CSC phenotype. However, the role of FBXW7 in lung CSCs and their resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in NSCLC is not fully understood. In this study, we developed GRPs from the two NSCLC cell lines PC9 and HCC827, which express an EGFR exon 19 deletion mutation, by treatment with a high concentration of gefitinib. The GRPs from both PC9 and HCC827 cells expressed high levels of CD133 and FBXW7, but low levels of c-MYC. Cell cycle analysis demonstrated that the majority of GRPs existed in the G0/G1 phase. Knockdown of the FBXW7 gene significantly reduced the cell number of CD133-positive GRPs and reversed the cell population in the G0/G1-phase. We also found that FBXW7 expression in CD133-positive cells was increased and c-MYC expression was decreased in gefitinib-resistant tumors of PC9 cells in mice and in 9 out of 14 tumor specimens from EGFR-mutant NSCLC patients with acquired resistance to gefitinib. These findings suggest that FBXW7 plays a pivotal role in the maintenance of quiescence in gefitinib-resistant lung CSCs in EGFR mutation-positive NSCLC.

Notch Signaling Enhances Stemness by Regulating Metabolic Pathways Through Modifying p53, NF-κB, and HIF-1α.

Human adipose-derived mesenchymal stromal cells (hASCs) are attractive for regenerative medicine, but their limited in vitro life span limits their therapeutic applicability. Recent data demonstrate that hypoxia may benefit the ex vivo culture of stem cells. Such cells exhibit a high level of glycolytic metabolism under hypoxic conditions. However, the physiological role of glycolytic activation and its underlying regulatory mechanism are incompletely understood. We have shown that when activated under conditions of 5% O2, Notch signaling dramatically increases the rate of glycolysis, improves proliferation efficiency, prevents senescence, and maintains the multipotency of hASCs. In the present study, we found that activated Notch1 enhanced nuclear p65 levels, resulting in an increase in glucose metabolism through the upregulation of glycolytic factors, including GLUT3. Notch signaling was also involved in glucose metabolism through p53 inactivation. We also found that NF-κB signaling was regulated by p53. These data suggest that Notch-HES1 signaling enhances the glycolytic pathway through p53 and NF-κB. Our data also revealed that activated Notch1 markedly increased the transcriptional activity of hypoxia-inducible factor 1 (HIF-1). Knockdown of HIF-1α significantly attenuated glycolysis induced by activated Notch1, indicating that the glycolysis pathway is regulated by the coordination of Notch signaling and HIF. Overall, our observations provide new regulatory mechanisms for the glycolysis by Notch signaling to maintain the stemness of hASCs.

The effect of kinetics of C-reactive protein in the prediction of overall survival in patients with metastatic renal cell carcinoma treated with tyrosine kinase inhibitor.

INTRODUCTION AND OBJECTIVES: The aim of this study was to investigate the effect of kinetics of C-reactive protein (CRP) in the prediction of overall survival (OS) in patients with metastatic renal cell carcinoma (mRCC) treated with a tyrosine kinase inhibitor. MATERIALS AND METHODS: The CRP in 118 cases of molecular-targeted therapy for mRCC was measured before starting the prescription of the first-line targeted agents and at the first time a CT scan was conducted during treatments. All cases were classified into higher-CRP groups and lower ones according to their data at the time of starting treatments. A higher-CRP group was further classified into 2 subgroups based on the kinetics after first-line targeted therapy: "decreased-CRP subgroup" and "nondecreased CRP subgroup." RESULTS: The median of the observation period was 23.4 months. The OS in cases with CRP higher than 0.5mg/dl was significantly worse than those in other cases (P<0.0001). Multivariate analysis revealed that the pretreated CRP (hazard ratio = 2.093; 95% CI: 1.176-3.858; P = 0.0179) was an independent predictive factor of OS. In the higher-CRP group, the OS for the decreased-CRP subgroup (1 year, 85.0%) was significantly better than those for the nondecreased CRP subgroup (1 year, 37.2%, P<0.0001). Multivariate analyses in the higher-CRP group revealed that the decrease in the CRP was an independent predictive factor for OS (hazard ratio = 0.176; 95% CI: 0.064-0.488; P = 0.0008). CONCLUSION: A decrease in CRP as well as pretreatment CRP can be a predictive factor for OS in patients with mRCC treated with a tyrosine kinase inhibitor. Cases with mRCC could be stratified into 3 groups with different prognoses using the pretreated CRP and its changes.

Identification of ACA-28, a 1'-acetoxychavicol acetate analogue compound, as a novel modulator of ERK MAPK signaling, which preferentially kills human melanoma cells.

The extracellular signal-regulated kinase (ERK) signaling pathway is essential for cell proliferation and is frequently deregulated in human tumors such as melanoma. Melanoma remains incurable despite the use of conventional chemotherapy; consequently, development of new therapeutic agents for melanoma is highly desirable. Here, we carried out a chemical genetic screen using a fission yeast phenotypic assay and showed that ACA-28, a synthetic derivative of 1'-acetoxychavicol acetate (ACA), which is a natural ginger compound, effectively inhibited the growth of melanoma cancer cells wherein ERK MAPK signaling is hyperactivated due to mutations in the upstream activating regulators. ACA-28 more potently inhibited the growth of melanoma cells than did the parental compound ACA. Importantly, the growth of normal human epidermal melanocytes (NHEM) was less affected by ACA-28 at the same 50% inhibitory concentration. In addition, ACA-28 specifically induced apoptosis in NIH/3T3 cells which were oncogenically transformed with human epidermal growth factor receptor-2 (HER2/ErbB2), but not in the parental cells. Notably, the ACA-28-induced apoptosis in melanoma and HER2-transformed cells was abrogated when ERK activation was blocked with a specific MEK inhibitor U0126. Consistently, ACA-28 more strongly stimulated ERK phosphorylation in melanoma cells, as compared in NHEM. ACA-28 might serve as a promising seed compound for melanoma treatment.

BNIP3 upregulation via stimulation of ERK and JNK activity is required for the protection of keratinocytes from UVB-induced apoptosis.

The human skin has an important role in barrier function. Ultraviolet rays (UV) from sunlight exposure can cause cell apoptosis in the skin epidermis, resulting in the disruption of the barrier. Previously, we have demonstrated that BNIP3 stimulates autophagy in epidermal keratinocytes and has a protective effect in these cells upon UVB irradiation. In this study, we found that the accumulation of reactive oxygen species (ROS) by UVB irradiation was sufficient to trigger the activation of JNK and ERK mitogen-activated protein kinase (MAPK) in human primary epidermal keratinocytes. In turn, activated JNK and ERK MAPK mediated the upregulation of BNIP3 expression. Treatment with an antioxidant reagent or a specific inhibitor of MAPK, U0126, and a JNK inhibitor significantly attenuated the expression of BNIP3 triggered by UVB, followed by the induction of cell death by apoptosis. Furthermore, UVB-induced apoptosis was significantly stimulated by chloroquine or bafilomycin A1, an inhibitor of autophagy. Moreover, BNIP3 was required for the degradation of dysfunctional mitochondria upon UVB irradiation. These data clearly indicated that BNIP3-induced autophagy, which occurs via UVB-generated ROS-mediated JNK and ERK MAPK activation, has a crucial role in the protection of the skin epidermis against UVB irradiation.

Beneficial Effects of the Genus Aloe on Wound Healing, Cell Proliferation, and Differentiation of Epidermal Keratinocytes.

Aloe has been used as a folk medicine because it has several important therapeutic properties. These include wound and burn healing, and Aloe is now used in a variety of commercially available topical medications for wound healing and skin care. However, its effects on epidermal keratinocytes remain largely unclear. Our data indicated that both Aloe vera gel (AVG) and Cape aloe extract (CAE) significantly improved wound healing in human primary epidermal keratinocytes (HPEKs) and a human skin equivalent model. In addition, flow cytometry analysis revealed that cell surface expressions of ß1-, α6-, ß4-integrin, and E-cadherin increased in HPEKs treated with AVG and CAE. These increases may contribute to cell migration and wound healing. Treatment with Aloe also resulted in significant changes in cell-cycle progression and in increases in cell number. Aloe increased gene expression of differentiation markers in HPEKs, suggesting roles for AVG and CAE in the improvement of keratinocyte function. Furthermore, human skin epidermal equivalents developed from HPEKs with medium containing Aloe were thicker than control equivalents, indicating the effectiveness of Aloe on enhancing epidermal development. Based on these results, both AVG and CAE have benefits in wound healing and in treatment of rough skin.

Inhibitory Effects of Oligostilbenoids from the Bark of Shorea roxburghii on Malignant Melanoma Cell Growth: Implications for Novel Topical Anticancer Candidates.

Human malignant melanomas remain associated with dismal prognosis due to their resistance to apoptosis and chemotherapy. There is growing interest in plant oligostilbenoids owing to their pleiotropic biological activities, including anti-inflammatory, antioxidant, and anticancer effects. Recent studies have demonstrated that resveratrol, a well-known stilbenoid from red wine, exhibits cell cycle-disrupting and apoptosis-inducing activities on melanoma cells. The objective of our study was to evaluate the anti-melanoma effect of oligostilbenoids isolated from the bark of Shorea roxburghii. Among the isolates, four resveratrol oligomers, i.e., (-)-hopeaphenol, vaticanol B, hemsleyanol D, and (+)-α-viniferin, possessed more potent antiproliferative action than did resveratrol against SK-MEL-28 melanoma cells. Cell cycle analysis revealed that (-)-hopeaphenol, hemsleyanol D, and (+)-α-viniferin arrested cell division cycle at the G1 phase, whereas vaticanol B had little effect on the cell cycle. In addition, cell proliferation assay also revealed that (+)-α-viniferin induced DNA damage followed by induction of apoptosis in SK-MEL-28 cells, which was confirmed by an increased expression of γ-H2AX and cleaved caspase-3, respectively. The compounds vaticanol B, hemsleyanol D, and resveratrol significantly increased the expression of p21, suggesting that they are able to block cell cycle progression. Moreover, these oligostilbenoids downmodulated cylin D1 expression and extracellular signal-regulated kinase (ERK) activation. Furthermore, hemsleyanol D, (+)-α-viniferin, and resveratrol significantly decreased the expression of cyclin B1, which could also suppress cell cycle progression. The present study thus suggests that these plant oligostilbenoids are effective as therapeutic or chemopreventive agents against melanoma.

[Primary Squamous Cell Carcinoma of the Prostate in which Docetaxel Therapy was Effective : A Case Report].

The patient was a 73-year-old man who visited our hospital with asymptomatic gross hematuria. Cystoscopy revealed a bladder tumor in two places. Serum prostatic specific antigen was normal (2.535 ng/ml). Transurethral resection of bladder tumors was performed. In order to complete resection of bladder tumor, transurethral resection of right lobe of the prostate whitch had protruded into the bladder, was needed. Histology of the prostatic tissue revealed squamous cell carcinoma with no grandular and acinar structures. Serum SCC-antigen level was evaluated (6.2 ng/ml) after establishment of the diagnosis. Thoraco-abdominal computed tomography and 18-fluorodeoxyglucose positron emission tomography/ computed tomography ((18)F-FDG PET/CT) showed prostate cancer and multiple metastases in the lymph nodes, such as right external iliac, right common iliac, para-aortic and left supraclavicular region. The patient received external radiation therapy to the prostate and underwent systemic chemotherapy using docetaxel. After 2 courses of docetaxel therapy, multiple lymph nodes metastases were reduced and serum SCC-antigen level was normalized. Docetaxel therapy could not be continued because of a side effect of interstitial pneumonia.

Oct4 plays a crucial role in the maintenance of gefitinib-resistant lung cancer stem cells.

Several recent studies have suggested that cancer stem cells (CSCs) are involved in resistance to gefitinib in non-small cell lung cancer (NSCLC). Oct4, a member of the POU-domain transcription factor family, has been shown to be involved in CSC properties of various cancers. We previously reported that Oct4 and the putative lung CSC marker CD133 were highly expressed in gefitinib-resistant persisters (GRPs) in NSCLC cells, and GRPs exhibited characteristic features of the CSCs phenotype. The aim of this study was to elucidate the role of Oct4 in the resistance to gefitinib in NSCLC cells with an activating epidermal growth factor receptor (EGFR) mutation. NSCLC cell lines, PC9, which express the EGFR exon 19 deletion mutation, were transplanted into NOG mice, and were treated with gefitinib in vivo. After 14-17 days of gefitinib treatment, the tumors still remained; these tumors were referred to as gefitinib-resistant tumors (GRTs). PC9-GRTs showed higher expression of Oct4 and CD133. To investigate the role of Oct4 in the maintenance of gefitinib-resistant lung CSCs, we introduced the Oct4 gene into PC9 and HCC827 cells carrying an activating EGFR mutation by lentiviral infection. Transfection of Oct4 significantly increased CD133-positive GRPs and the number of sphere formation, reflecting the self-renewal activity, of PC9 and HCC827 cells under the high concentration of gefitinib in vitro. Furthermore, Oct4-overexpressing PC9 cells (PC9-Oct4) significantly formed tumors at 1 × 10 cells/injection in NOG mice as compared to control cells. In addition, PC9-Oct4 tumors were more resistant to gefitinib treatment as compared to control cells in vivo. Finally, immunohistochemical analysis revealed that Oct4 was highly expressed in tumor specimens of EGFR-mutant NSCLC patients with acquired resistance to gefitinib. Collectively, these findings suggest that Oct4 plays a pivotal role in the maintenance of lung CSCs resistant to gefitinib in EGFR mutation-positive NSCLC.