Emerging therapeutic strategies for metastatic uveal melanoma: Targeting driver mutations.

Uveal melanoma (UM) is the most common primary malignant intraocular tumor in adults. Although primary UM can be effectively controlled, a significant proportion of cases (40% or more) eventually develop distant metastases, commonly in the liver. Metastatic UM remains a lethal disease with limited treatment options. The initiation of UM is typically attributed to activating mutations in GNAQ or GNA11. The elucidation of the downstream pathways such as PKC/MAPK, PI3K/AKT/mTOR, and Hippo-YAP have provided potential therapeutic targets. Concurrent mutations in BRCA1 associated protein 1 (BAP1) or splicing factor 3b subunit 1 (SF3B1) are considered crucial for the acquisition of malignant potential. Furthermore, in preclinical studies, actionable targets associated with BAP1 loss or oncogenic mutant SF3B1 have been identified, offering promising avenues for UM treatment. This review aims to summarize the emerging targeted and epigenetic therapeutic strategies for metastatic UM carrying specific driver mutations and the potential of combining these approaches with immunotherapy, with particular focus on those in upcoming or ongoing clinical trials.

Reciprocal positive regulation between BRD4 and YAP in GNAQ-mutant uveal melanoma cells confers sensitivity to BET inhibitors.

Uveal melanoma (UM) is the most common intraocular cancer in adults. UMs are usually initiated by a mutation in GNAQ or GNA11 (encoding Gq or G11, respectively), unlike cutaneous melanomas (CMs), which usually carry a BRAF or NRAS mutation. Currently, there are no clinically effective targeted therapies for UM carrying Gq/11 mutations. Here, we identified a causal link between Gq activating mutations and hypersensitivity to bromodomain and extra-terminal (BET) inhibitors. BET inhibitors transcriptionally repress YAP via BRD4 regardless of Gq mutation status, independently of Hippo core components LATS1/2. In contrast, YAP/TAZ downregulation reduces BRD4 transcription exclusively in Gq-mutant cells and LATS1/2 double knockout cells, both of which are featured by constitutively active YAP/TAZ. The transcriptional interdependency between BRD4 and YAP identified in Gq-mutated cells is responsible for the preferential inhibitory effect of BET inhibitors on the growth and dissemination of Gq-mutated UM cells compared to BRAF-mutated CM cells in both culture cells and animal models. Our findings suggest BRD4 as a viable therapeutic target for Gq-driven UMs that are addicted to unrestrained YAP function.

PTEN loss confers sensitivity to rapalogs in clear cell renal cell carcinoma.

Rapalogs (everolimus and temsirolimus) are allosteric mTORC1 inhibitors and approved agents for advanced clear cell renal cell carcinoma (ccRCC), although only a subset of patients derive clinical benefit. Progress in genomic characterization has made it possible to generate comprehensive profiles of genetic alterations in ccRCC; however, the correlations between recurrent somatic mutations and rapalog efficacy remain unclear. Here, we demonstrate by using multiple patient-derived ccRCC cell lines that compared to PTEN-proficient cells, PTEN-deficient cells exhibit hypersensitivity to rapalogs. Rapalogs inhibit cell proliferation by inducing G0/G1 arrest without inducing apoptosis in PTEN-deficient ccRCC cell lines. Using isogenic cell lines generated by CRISPR/Cas9, we validate the correlation between PTEN loss and rapalog hypersensitivity. In contrast, deletion of VHL or chromatin-modifying genes (PBRM1, SETD2, BAP1, or KDM5C) fails to influence the cellular response to rapalogs. Our mechanistic study shows that ectopic expression of an activating mTOR mutant (C1483F) antagonizes PTEN-induced cell growth inhibition, while introduction of a resistant mTOR mutant (A2034V) enables PTEN-deficient ccRCC cells to escape the growth inhibitory effect of rapalogs, suggesting that PTEN loss generates vulnerability to mTOR inhibition. PTEN-deficient ccRCC cells are more sensitive to the inhibitory effects of temsirolimus on cell migration and tumor growth in zebrafish and xenograft mice, respectively. Of note, PTEN protein loss as detected by immunohistochemistry is much more frequent than mutations in the PTEN gene in ccRCC patients. Our study suggests that PTEN loss correlates with rapalog sensitivity and could be used as a marker for ccRCC patient selection for rapalog therapy.

BAP1 loss augments sensitivity to BET inhibitors in cancer cells.

The tumor suppressor gene BAP1 encodes a widely expressed deubiquitinase for histone H2A. Both hereditary and acquired mutations are associated with multiple cancer types, including cutaneous melanoma (CM), uveal melanoma (UM), and clear cell renal cell carcinoma (ccRCC). However, there is no personalized therapy for BAP1-mutant cancers. Here, we describe an epigenetic drug library screening to identify small molecules that exert selective cytotoxicity against BAP1 knockout CM cells over their isogenic parental cells. Hit characterization reveals that BAP1 loss renders cells more vulnerable to bromodomain and extraterminal (BET) inhibitor-induced transcriptional alterations, G1/G0 cell cycle arrest and apoptosis. The association of BAP1 loss with sensitivity to BET inhibitors is observed in multiple BAP1-deficient cancer cell lines generated by gene editing or derived from patient tumors as well as immunodeficient xenograft and immunocompetent allograft murine models. We demonstrate that BAP1 deubiquitinase activity reduces sensitivity to BET inhibitors. Concordantly, ectopic expression of RING1A or RING1B (H2AK119 E3 ubiquitin ligases) enhances sensitivity to BET inhibitors. The mechanistic study shows that the BET inhibitor OTX015 exerts a more potent suppressive effect on the transcription of various proliferation-related genes, especially MYC, in BAP1 knockout cells than in their isogenic parental cells, primarily by targeting BRD4. Furthermore, ectopic expression of Myc rescues the BET inhibitor-sensitizing effect induced by BAP1 loss. Our study reveals new approaches to specifically suppress BAP1-deficient cancers, including CM, UM, and ccRCC.

Terahertz magneto-optical effect of wafer-scale La: yttrium iron garnet single-crystal film with low loss and high permittivity.

The wafer-scale La:YIG single crystal thick films were fabricated on a three-inch gadolinium gallium garnet (GGG) substrate by liquid phase epitaxy method. The terahertz (THz) optical and magneto-optical properties of La:YIG film were demonstrated by THz time domain spectroscopy (THz-TDS). The results show that a high refractive index of approximately 4.09 and a low absorption coefficient of 10-50 cm-1 from 0.1 to 1.6 THz for this La:YIG film. Moreover, the THz Faraday rotation effect of La:YIG film was measured by the orthogonal polarization detection method in THz-TDS system, which can be actively manipulated by a weak longitudinal magnetic field of up to 0.155 T. With 5 samples stacked together, the Faraday rotation angle varies linearly from -15° to 15°, and the Verdet constant of La:YIG is about 100 °/mm/T within the saturation magnetization. This magneto-optical single crystal thick film with large area shows low loss, high permittivity and strong magneto-optical effect in the THz regime, which will be widely used in magneto-optical polarization conversion, nonreciprocal phase shifter and isolator for THz waves.

Susceptibility of epithelial tumour cell lines to hyperthermia.

BACKGROUND: Human skin or mucosa exposes cells to both an internal and exogeneous thermal environment and the cells survive within a certain range of temperature. Exogeneous hyperthermia has been applied for the treatment of various types of cancers, fungal disease, and warts. OBJECTIVES: To determine whether different cellular components in the skin adapt to hyperthermic conditions differentially and further elucidate the mechanisms involved. MATERIALS & METHODS: Cell lines derived from normal and tumour epithelial cells were treated with hyperthermic conditions and tested for viability (using an MTS assay), apoptosis (using a FITC-conjugated annexin V apoptosis detection kit), and changes in intracellular calcium (using a calcium-sensitive fluorescent single-wavelength dye, Fluo-4 AM). RESULTS: Thermo-resistance of different cell types was different when cells were subjected to heat at 45̊C for 30 minutes. Stronger effects of hyperthermia were noted on cell viability and apoptosis in epidermal cells relative to their malignant counterparts, except for cell lines harbouring human papillomavirus (HPV). Hyperthermia had a much greater effect on cell viability and apoptosis in a HPV-negative cell line compared to HPV-positive cell lines. We further found that hyperthermia treatment resulted in a strong calcium influx which led to apoptotic cells. However, no obvious increase in apoptosis was observed in cells treated with the CRAC channel selective inhibitor, BTP2, before application of hyperthermia in all cell types, except three cervical cell lines harbouring HPV. CONCLUSION: We propose that hyperthermia results in a CRAC-related strong calcium influx which induces apoptosis, with the exception of HPV-positive cells.

Infrared-induced adult colloid milium treated with fractionated CO2 laser.

Adult colloid milium is a rare cutaneous deposition disorder that frequently involves areas of chronic sun exposure. The most common clinical presentation exhibits multiple, firm, and amber-colored papules that cluster to form large plaques. Histologically, there are masses of amorphous, eosinophilic material expanding the papillary dermis, and at times extending into the mid-dermis, with adjacent solar elastosis. When this disorder affects the face, disfiguring is of great concern and treatment is often sought. Attempts to safely remove colloid milium are generally unsuccessful. Dermabrasion has been reported to be effective. The present authors present a case with extensive facial colloid milium successfully ablated by the fractionated CO2 laser.

Synthesis and biological evaluation of dehydroepiandrosterone-fused thiazole, imidazo[2,1-b]thiazole, pyridine steroidal analogues.

A series of steroidal[17,16-d]thiazole, steroidal[1,2-b]pyridine and steroidal[17,16-d]thiazole[2,1-b]imidazo products were synthesized through a convenient and productive method. Anti-proliferation activity against EC109 (human esophageal carcinoma), EC9706 (human esophageal carcinoma) and MGC-803 (human gastric carcinoma) cell lines was examined in vitro. Among the screened compounds, several highly potential compounds were located.

[Mechanism of E1A-mediated escape from ras-induced senescence in human fibraoblasts].

OBJECTIVE: To study the effect of binding activities of the NH(2) terminus of E1A to the proteins regulating cell growth on ras-induced cell senescence and explore the mechanism of E1A-mediated escape from ras-induced senescence by E1A in human fibroblast. METHODS: In primary human fibroblasts, the proteins regulating cell growth in association with E1A NH(2) terminus, including the Rb family proteins, p300/CBP, and p400, were inactivated or interfered. The effect of alterations in the binding activities of these proteins on cell senescence bypass mediated by E1A was evaluated by cell growth curve. RESULTS: The Inactivation of Rb family proteins alone was not sufficient to rescue ras-induced cell senescence, whereas inactivation of both the Rb proteins and p300/CBP blocked ras-induced senescence of human fibroblasts. CONCLUSION: Rb and p300/CBP binding activities are both required for E1A to bypass ras-induced senescence in human fibroblasts.

[Cisplatin induces drug resistance in human esophageal squamous carcinoma cell line EC109 by decreasing CTR1 protein expression].

OBJECTIVE: To investigate the mechanism of the development of cisplatin resistance in a human esophageal squamous carcinoma cell line. METHODS: The cytotoxicity of cisplatin in the cisplatin-resistant resistant cell line EC109/CDDP and its parental cell line EC109 was measured by MTT assay. Whole-cell cisplatin accumulation and Pt-DNA adduct formation were determined by inductively coupled plasma mass spectrometry (ICP-MS). Western blotting was used to investigate the protein expression of full length PARP, cleaved PARP, and copper transporter 1 (CTR1). RESULTS: EC109/CDDP cells was more resistant to cisplatin-induced cytotoxicity and apoptosis than EC109 cells. Compared with EC109 cells, EC109/CDDP cells exhibited less cisplatin accumulation and Pt-DNA adduct formation with also decreased CTR1 protein expression. CONCLUSION: Cisplatin induces drug resistant phenotype by decreasing the protein level of CTR1, which controls cell accumulation and cytotoxic effect of cisplatin.

Therapeutic effects of melatonin on heatstroke-induced multiple organ dysfunction syndrome in rats.

Melatonin reportedly exerts beneficial effects to attenuate multiple organ dysfunction syndrome (MODS) in septic shock. Heatstroke resembles septic shock in many aspects. Thus, this study was performed on the anesthetized rats by using heat exposure to induce heatstroke-associated MODS. We evaluated the effect of melatonin, a versatile molecule synthesized in the pineal gland and in many organs, in heatstroke rats and showed that melatonin (0.2-5.0 mg/kg of body weight, i.v., immediately after the start of heat stress) significantly (i) attenuated hyperthermia, hypotension and hypothalamic ischemia and hypoxia, (ii) reduced plasma index of the toxic oxidizing radicals like nitric oxide metabolites and hydroxyl radicals, (iii) diminished plasma index of hepatic and renal dysfunction like creatinine, blood urea nitrogen, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase, (iv) attenuated plasma systemic inflammation response molecules like soluble intercellular and lesion molecule-1, E-selectin, tumor necrosis factor-alpha, interleukin (IL)-1ß, and IL-6, (v) promoted plasma levels of an anti-inflammatory cytokine IL-10, (vi) reduced an index of infiltration of polymorphonuclear neutrophils in the lung like myeloperoxidase activity, and (vii) promoted the survival time to fourfold compared with the heatstroke alone group. Thus, melatonin could be a novel agent for the treatment of heatstroke animals or patients in the early stage.

[MT1-MMP up-regulates VEGF expression in human breast carcinoma MCF-7 cells and induces tumor angiogenesis].

OBJECTIVE: To study the function of MT1-MMP in tumor angiogenesis and elucidate the possible way of action that MT1-MMP contributes to angiogenesis. METHODS: MT1-MMP was transfected into human breast carcinoma cell line MCF-7 cells. Semi-quantitative RT-PCR and immunofluorescence staining were employed to detect the expression of VEGF in the transfected and non-transfected MCF-7 cells. Tumor growth, microvessel density and expression of VEGF in nude mice were detected through in vivo tumorigenicity assay. RESULTS: In MT1-MMP stable transfected MCF-7 cells, mRNA expression of VEGF(189), VEGF(165), and VEGF(121) and immunofluorescence intensity were significantly elevated (P < 0.001). In vivo tumorigenicity assay in the nude mice showed that MT1-MMP promoted tumor growth. The MVD in the MT1-MMP-transfected cells-transplanted tumor tissue was significantly elevated (P < 0.05). Immunohistochemical assay showed that there was a strong immunostaining of VEGF in those tumor tissues. CONCLUSION: MT1-MMP can induce tumor angiogenesis through up-regulation of VEGF expression. This function of MT1-MMP may open a new approach for clinical anti-tumor research and anti-tumor drug development.

Activated protein C can be used as a prophylactic as well as a therapeutic agent for heat stroke in rodents.

The present study was attempted to assess the prophylactic and the therapeutic effect of human recombinant activated protein C (APC; drotrecogin-alpha, activated) in experimental heat stroke. Anesthetized rats were divided into two groups and given vehicle solution 1 h before the start or immediately after the termination of heat stress (isotonic sodium chloride solution, 2 mL kg(-1) of body weight, i.v.) or APC (1-10 mg in 2 mL of isotonic sodium chloride solution per kilogram of body weight, i.v.). They were exposed to ambient temperature of 40 degrees C for 100 min to induce heat stroke. When the vehicle-pretreated rats underwent heat stress, their survival time values were found to be 57 to 71 min. Pretreatment or treatment with APC significantly increased survival time (122-221 min). All vehicle-pretreated heat stroke animals displayed systemic inflammation (evidenced by increased TNF-alpha, IL-1alpha, and IL-6) and activated coagulation (evidenced by increased levels of activated partial thromboplastin time, prothrombin time, and D-dimer and decreased levels of both platelet count and protein C). Biochemical assay also revealed that both renal and hepatic dysfunction (e.g., increased plasma levels of blood urea nitrogen, creatinine, adenine aminotransferase, aspartate aminotransferase, and alkaline phosphatase) were noted during heat stroke. A significant decrease in both cerebral blood flow and partial pressure of oxygen in hypothalamus were also observed in vehicle-pretreated heat stroke animals. These heat stroke reactions were all significantly reduced by pretreatment or treatment with human recombinant APC. The results indicate that human recombinant APC can be used as a prophylactic and a therapeutic agent for experimental heat stroke by ameliorating systemic inflammation, hypercoagulable state, and multiple organ dysfunction.

[Transfection with human adenovirus type 5 early-region 1A protects the primary human fibroblasts from ras-induced premature senescence in vitro].

OBJECTIVE: To investigate the role of human adenovirus type 5 (Ad5) early-region 1A (E1A) in premature senescence of human fibroblasts induced by Ras activation. METHODS: Human fibroblasts were cotransduced with E1A, E1A1-143, or their vector (BP) and Ha-RasV12 or its vector (WH). The growth curves and percentages of the apoptotic cells were determined. RESULTS: Expression of E1A or Ha-RasV12 in human fibroblasts significantly inhibited the cell growth. Transduction of Ha-RasV12 along with E1A or E1A 1-143 into human fibroblast cells resulted in active and rapid cell proliferation. CONCLUSION: E1A can rescue human fibroblasts from Ras-induced premature senescence, and the senescence bypassing activity of E1A resides in its NH2 terminus.

[Analysis of human normal prostate cells membrane proteins by shotgun-MS coupled with laser capture microdissection].

OBJECTIVE: To analyze of membrane proteins of human normal prostate epithelial cells. METHODS: Laser capture microdissection (LCM) technique was utilized to obtain the epithelial cells of human normal prostate. Shotgun-MS was used to generate protein profiles in the epithelial cells of human normal prostate. RESULTS: LCM technique successfully separated the normal prostate epithelial cells with homogeneity more than 95%. Under a stringent filter condition (charge +1, Xcorr >/= 1.9; charge +2, Xcorr >/= 2.2; charge +3, Xcorr >/= 3.75; DelCN >/= 0.1), 1164 proteins were identified in the human normal prostate cells, of which 799 had a gene ontology annotation (GOA) indicating a cellular component, others have no GOA terms. Among the GOA terms, 377 (49.15%) were known membrane proteins or membrane associated proteins. In addition to the proteins known to be associated with the membrane, a significant number of novel proteins had also been identified, including several hypothetical proteins and cDNA sequences. CONCLUSION: Shotgun-MS technique coupled with LCM effectively analyzes the proteins of human normal prostate cells, thus helping perfect the complete protein profiles of human normal prostate cells.

Expression of the human phosphatases of regenerating liver (PRLs) in colonic adenocarcinoma and its correlation with lymph node metastasis.

BACKGROUND: Human phosphatases of regenerating liver (PRLs) can induce cell growth, differentiation, and malignant transformation. In this study, we used specific polyclonal antibodies against PRLs to investigate their expression in colonic adenocarcinomas and its correlation with patient gender, age, tumor differentiation, localization, invasion, and metastasis. MATERIALS AND METHODS: The polyclonal antibodies against PRL-1, PRL-2, and PRL-3 were produced and purified. The expression of PRLs in human colorectal carcinoma cell lines (SW480 and SW620) was examined by Western blotting. We also examined their expression in normal and pathologic tissues from the human colon. The tissues included 49 primary colonic adenocarcinomas, 14 cases with lymph node metastases, 15 colonic adenomas, and 12 normal colon samples. Hematoxylin and eosin staining, immunohistochemistry, and semiquantitative morphological analysis were used to evaluate the sections. RESULTS: PRLs were widely expressed in SW480 and SW620. PRL-1, PRL-2, and PRL-3 were expressed, respectively, in 16, 10, and 16% of primary colonic adenocarcinomas. In contrast, PRLs were strongly expressed in all lymph node metastases. There were no significant correlations between the expression of PRLs and patient gender, age, tumor differentiation, depth of invasion, or localization of tumor within the different sections of the colon. PRLs were not expressed in normal colon tissues or in colonic adenomas. PRLs were mainly expressed in the cytoplasm and at the cytoplasmic membranes of the colonic adenocarcinoma cells as well as in the endothelial cells and the surrounding smooth muscle cells of larger vessels in the lymph node metastases. CONCLUSION: Colonic adenocarcinoma cells have the ability to produce PRLs, which may relate to the lymph node metastasis of colonic adenocarcinoma.

[Effects of nolatrexed on thymidylate synthase protein expression].

OBJECTIVE: To study the dynamic changes in thymidylate synthase (TS) expression in different cell lines treated with nolatrexed. METHODS: For studying the time course of the action of the drug, LoVo and Lo2 cells were treated separately with nolatrexed at the concentrations of 10 and 75 micromol/L (approximately their respective IC(90) value) for 0 to 60 h, while in the dose response study, treatment with nolatrexed for 36 h was performed with the dose range of 0 to 40 micromol/L for LoVo cells and 0 to 125 micromol/L for Lo2 cell. TS expression was detected by flow cytometry and Western blotting. RESULTS: The dynamic changes in TS expression with respect of the time course and dose response differed significantly in the two cell lines after nolatrexed treatment. In the time course study, TS expression increased continuously in LoVo cells, as compared with that in the control cells, whereas the TS expression initially decreased and then began to increase gradually 24 h after the treatment, remaining still below the control level after 60 h. In the dose response study, TS expression in LoVo cells gave rise to a peak in the curve, with the peak level approaching the IC(90) value. In Lo2 cells, when the concentration of nolatrexed was blow the IC(90) value, the decrement in TS expression were similar, but as the concentration exceeded the IC(90) value, TS expression decreased dose-dependently. CONCLUSION: Nolatrexed may elicit TS induction in the cells, and the difference in the dynamic changes of TS expression between different cell lines after nolatrexed treatment contributes to different profiles of drug resistance.

[Cloning, expression of soluble VEGFR2 fragment and its effect on tumor angiogenesis].

OBJECTIVE: To study the anti-tumor angiogenesis effect of soluble VEGF receptor fragment by blocking the combination of VEGF and its receptor in vivo and in vitro. METHODS: RT-PCR technique was used to amplify Flk-1/KDR fragment from embryo mouse liver, which was recombinated to expression vector pET-28b(+) and retrovirus vector PLXSN, which was induced to be expressed, purified and identified with EcoR I and Hind III. Mouse endothelial cells were separated, cultured and identified by immunocytochemistrical staining using VIII factor-related antigen antibody. The expressed product was analyzed about its effect on endothelial cell's growth in vitro with MTT method. The retrovirus vector was transfected to tumor cell lines S180 and B16 by liposome method to observe the biological specificity in vitro after gene transfection. RESULTS: 1000 bp size sVEGFR fragment was amplify from E9, E11 embryo mouse liver tissues, which was recombinated to TA clone vector and identified by sequence analysis. This fragment was cloned to expression vector pET-28b(+), the expressed product was purified and identified correctly. The in vitro study showed this expressed product can effectively inhibit endothelial cell(s), growth and proliferation. The fragment was then cloned to retrovirus vector PLXSN and transfected to tumor cell lines S180 and B16 successfully with RT-PCR and SDS-PAGE. The experiments in vivo showed that the weight of tumor smaller, the size decreased significantly, the microvessel density was fewer and Flk1 protein expression were higher in the group of gene transfection than that of control. CONCLUSION: Soluble VEGFR fragment is a kind of effective gene engineer product for anti-tumor angiogenesis gene therapy and the development of anti-tumor drug.