Piperazine-based Alpha-1 AR Blocker, Naftopidil, Selectively Suppresses Malignant Human Bladder Cells via Induction of Apoptosis.

A retrospective observational cohort study has shown that exposure to alpha-1 adrenergic receptor (AR) blocker reduces the risk of bladder cancer (BCa). We investigated the antitumor activity of alpha-1 blockers, that are administered long-term therapeutically, in BCa. The antitumor activity of alpha-1 blockers was evaluated in terms of cell viability, cell cycle, competition, and apoptotic signaling in BCa cells.

Oleic acid stimulates glucose uptake into adipocytes by enhancing insulin receptor signaling.

The present study investigated cis-unsaturated free fatty acid (FFA)-regulated glucose uptake. In the cell-free assay of protein tyrosine phosphatase 1B (PTP1B), cis-unsaturated FFAs such as linoleic, linolenic, and oleic acid significantly suppressed PTP1B activity in a concentration (1 - 100 μM)-dependent manner, with the highest potential for oleic acid. Oleic acid (1 μM) stimulated insulin (0.

Naftopidil is useful for the treatment of malignant pleural mesothelioma.

Naftopidil, an α1-adrenoceptor blocker, induced apoptosis of human malignant pleural mesothelioma NCI-H2052 cells. Naftopidil upregulated the expression of tumor necrosis factor-α (TNF-α) mRNA in these cells. Naftopidil, alternatively, increased FasL secretion from NCI-H2052 cells, without affecting the expression of FasL mRNA and protein, and activated caspase-3 and -8 in NCI-H2052 cells.

Newly synthesized anticancer drug HUHS1015 is effective on malignant pleural mesothelioma.

The newly synthesized naftopidil analogue HUHS1015 reduced cell viability in malignant pleural mesothelioma cell lines MSTO-211H, NCI-H28, NCI-H2052, and NCI-H2452, with the potential greater than that for the anticancer drugs paclitaxel or cisplatin at concentrations higher than 30 μM. HUHS1015 induced both necrosis and apoptosis of MSTO-211H and NCI-H2052 cells. HUHS1015 upregulated expression of mRNAs for Puma, Hrk, and Noxa in MSTO-211H and NCI-H2052 cells, suggesting HUHS1015-induced mitochondrial apoptosis.

PTP1B inhibition causes Rac1 activation by enhancing receptor tyrosine kinase signaling.

Background/aims: The present study investigated the signaling pathway underlying Rac1 activation induced by the linoleic acid derivative 8-[2-(2-pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA).

Methods: Activity of protein tyrosine phosphatase 1B (PTP1B) was assayed under cell-free conditions. Western blot was carried out to quantify phosphorylation of insulin receptor substrate-1 (IRS-1) and Akt in PC-12 cells.

Development of in vitro model of insulin receptor cleavage induced by high glucose in HepG2 cells.

Soluble insulin receptor (sIR), the ectodomain of IR, has been detected in human plasma, and its concentration parallels that of blood glucose in patients with diabetes. IR has a pivotal role in glucose homeostasis and diabetes development; therefore, cleavage of IR promoted by hyperglycemia is involved in insulin resistance and glucose toxicity. To elucidate the physiology of sIR, we developed an in vitro model mimicking the changes in sIR levels in plasma from patients with diabetes.

Stepwise assembly of fibrinogen is assisted by the endoplasmic reticulum lectin-chaperone system in HepG2 cells.

The endoplasmic reticulum (ER) plays essential roles in protein folding and assembly of secretory proteins. ER-resident molecular chaperones and related enzymes assist in protein maturation by co-operated interactions and modifications. However, the folding/assembly of multimeric proteins is not well understood.

Crosstalk between PI3 kinase/PDK1/Akt/Rac1 and Ras/Raf/MEK/ERK pathways downstream PDGF receptor.

Background/aims: Our earlier studies suggested crosstalk between IRS/PI3 kinase/PDK1/Akt/Rac1/ROCK and (Shc2/Grb2/SOS)/Ras/Raf/MEK/ERK pathways downstream PDGF-ββ receptor responsible for chemotaxis and proliferation of malignant mesothelioma cells. The present study was conducted to obtain evidence for this.

Methods: To assess activation of Akt, MEK, and ERK, Western blotting was carried out on MSTO-211H malignant mesothelioma cells using antibodies against phospho-Thr308-Akt, phopho-Ser473-Akt, Akt, phospho-MEK, MEK, phopho-ERK1/2, and ERK1/2.

Fiber-substituted conditionally replicating adenovirus Ad5F35 induces oncolysis of human bladder cancer cells in in vitro analysis.

Objective: To assess the oncolytic effect of fiber-substituted conditionally replicating adenovirus type 5 (Ad5) F35 vector on human bladder cancer cell lines such as 253J, 5637, KK-47, T24, TCCSUP, and UMUC-3 cells.

Materials And Methods: Ad5F35 and Ad5 conditionally replicating adenovirus vectors containing the E1 gene controlled by the human midkine promoter (Ad5F35/MKp-E1 and Ad5/MKp-E1, respectively) were constructed. Reverse transcriptase-polymerase chain reaction and cell viability assay were performed in cells transfected with Ad5F35/MKp-E1 or Ad5/MKp-E1.

A3 adenosine receptor mediates apoptosis in in vitro RCC4-VHL human renal cancer cells by up-regulating AMID expression.

Purpose: Accumulating studies have shown that extracellular adenosine induces apoptosis in various cancer cells via diverse signaling pathways. We sought to understand adenosine induced apoptosis in human renal cancer cells and the underlying pathway.

Materials And Methods: RCC4-VHL (European Collection of Animal Cell Cultures, Salisbury, United Kingdom), ACHN (Cell Resource Center for Biomedical Research, Institute of Development, Aging and Cancer, Tohuku University, Aoba-ku, Sendai, Japan) and 786-O (ATCC®) human renal cancer cells were cultured.

Antitumor action of α(1)-adrenoceptor blockers on human bladder, prostate and renal cancer cells.

The present study investigated the antitumor action of α(1)-adrenoceptor blockers on human bladder, prostate and renal cancer cells. For bladder cancer cell lines used here such as 253J, 5637, KK-47, T24 and UM-UC-3 cells, prazosin, a selective α(1)-adrenoceptor blocker, reduced cell viability at concentrations more than 30 µmol/l. Likewise, naftopidil, a blocker of α(1A)- and α(1D)-adrenoceptors, reduced cell viability for all the bladder cancer cells used here in a concentration (10-100 µmol/l)-dependent manner, with a much greater advantage than prazosin.

Gene therapy using adenovirus against malignant mesothelioma.

Background: Adenovirus vectors have been utilized for cancer gene therapies. The present study examined the oncolytic effects of adenovirus type 5 (Ad5) and fiber-substituted conditionally replicating adenovirus (CRAD) Ad5/F35 vectors on the human malignant mesothelioma cells MSTO-211H, NCI-H28, NCI-H2052, and NCI-H2452 cells.

Materials And Method: For the adenovirus, the first mRNA/protein to be made (~1 h after infection) is E1A.

Improved gene transfer into bladder cancer cells using adenovirus vector containing RGD motif.

Background: The transduction efficacy of adenovirus serotype 5 (Ad5) vector in high-grade human bladder cancer cells is generally extremely low due to the non-expression of coxsackie and adenoviral receptor (CAR). We investigated whether fiber-modified adenovirus vector containing an RGD motif in the HI loop of the adenovirus fiber knob could increase the transduction efficiency of Ad5 into human bladder cancer cells in vitro.

Materials And Methods: We examined the expressions of CAR, and of α(v), β(3) and β(5) integrin, and the transduction efficacy of fiber-modified adenovirus vector in four human bladder cancer cell lines (TCC-SUP, 253J, T24 and KK47).

Fiber-substituted conditionally replicating adenovirus for oncolysis of human renal carcinoma cells.

Background: Adenovirus vectors have lately been highlighted in gene therapies. We investigated the oncolytic effects of a chimeric adenovirus type 5 (Ad5) with replacement of Ad5 fiber knob with adenovirus type 35 (Ad35) fiber knob (Ad5F35) on human renal cell carcinoma (RCC).

Materials And Methods: The conditionally replicating Ad5F35 vector was constructed and infected into RCC cell lines 786-O, ACHN, and RCC4-VHL.

Cytochrome P450 in non-small cell lung cancer related to exogenous chemical metabolism.

The occurrence of lung cancer is associated with smoking, which exposes smokers to a series of carcinogenic chemicals. CYP (cytochrome P450) usually metabolizes carcinogens to their inactive derivatives, but occasionally convert the chemicals to more potent carcinogens. In addition to the metabolism of carcinogenic compounds, CYP also participates in the activation and/or inactivation of anti-carcinogenic agents, suggesting that the local CYP expression in lung cancer and surrounding tissues could be an important determinant of efficacy of anticancer drugs.

Regulated motion of glycoproteins revealed by direct visualization of a single cargo in the endoplasmic reticulum.

The quality of cargo proteins in the endoplasmic reticulum (ER) is affected by their motion during folding. To understand how the diffusion of secretory cargo proteins is regulated in the ER, we directly analyze the motion of a single cargo molecule using fluorescence imaging/fluctuation analyses. We find that the addition of two N-glycans onto the cargo dramatically alters their diffusion by transient binding to membrane components that are confined by hyperosmolarity.

Quantitative proteomics analysis of the secretory pathway.

We report more than 1400 proteins of the secretory-pathway proteome and provide spatial information on the relative presence of each protein in the rough and smooth ER Golgi cisternae and Golgi-derived COPI vesicles. The data support a role for COPI vesicles in recycling and cisternal maturation, showing that Golgi-resident proteins are present at a higher concentration than secretory cargo. Of the 1400 proteins, 345 were identified as previously uncharacterized.

Involvement of syntaxin 18, an endoplasmic reticulum (ER)-localized SNARE protein, in ER-mediated phagocytosis.

The endoplasmic reticulum (ER) is thought to play an important structural and functional role in phagocytosis. According to this model, direct membrane fusion between the ER and the plasma or phagosomal membrane must precede further invagination, but the exact mechanisms remain elusive. Here, we investigated whether various ER-localized SNARE proteins are involved in this fusion process.

Involvement of a novel Q-SNARE, D12, in quality control of the endomembrane system.

The cellular endomembrane system requires the proper kinetic balance of synthesis and degradation of its individual components, which is maintained in part by a specific membrane fusion apparatus. In this study, we describe the molecular properties of D12, which was identified from a mouse expression library. This C-terminal anchored membrane protein has sequence similarity to both a yeast soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor (SNARE), Use1p/Slt1p, and a recently identified human syntaxin 18-binding protein, p31.

Regulation of immature protein dynamics in the endoplasmic reticulum.

The quality of nascent protein folding in vivo is influenced by the microdynamics of the proteins. Excessive collisions between proteins may lead to terminal misfolding, and the frequency of protein interactions with molecular chaperones determines their folding rates. However, it is unclear how immature protein dynamics are regulated.

Diacylglycerol kinase delta suppresses ER-to-Golgi traffic via its SAM and PH domains.

We report here that the anterograde transport from the endoplasmic reticulum (ER) to the Golgi was markedly suppressed by diacylglycerol kinase delta (DGKdelta) that uniquely possesses a pleckstrin homology (PH) and a sterile alpha motif (SAM) domain. A low-level expression of DGKdelta in NIH3T3 cells caused redistribution into the ER of the marker proteins of the Golgi membranes and the vesicular-tubular clusters (VTCs). In this case DGKdelta delayed the ER-to-Golgi traffic of vesicular stomatitis virus glycoprotein (VSV G) and also the reassembly of the Golgi apparatus after brefeldin A (BFA) treatment and washout.