[Clinical trials on intrathecal pemetrexed treated leptomeningeal metastases from solid tumors].

Objective: To investigate the feasibility, safety and efficacy of intrathecal pemetrexed (IP) treated for patients with leptomeningeal metastases (LM) from solid tumors. Methods: Forty-seven patients receiving pemetrexed intrathecal chemotherapy in the First Hospital of Jilin University from 2017 to 2018 were selected. The study of pemetrexed intrathecal chemotherapy adopted the classical dose-climbing model and included 13 patients with meningeal metastasis of non-small cell lung cancer who had relapsed and refractory after multiple previous treatments including intrathecal chemotherapy. Based on the dose climbing study, 34 patients with meningeal metastasis of solid tumor who did not receive intrathecal chemotherapy were enrolled in a clinical study using pemetrexed as the first-line intrathecal chemotherapy combined with radiotherapy. Kaplan-Meier method and Log rank test were used for survival analysis, and Cox regression model was used for influencing factor analysis. Results: The dose climbing study showed that the maximum tolerated dose of pemetrexed intrathecal chemotherapy was 10 mg per single dose, and the recommended dosing regimen was 10 mg once or twice a week. The incidence of adverse reactions was 10 cases, including hematological adverse reactions (7 cases), transaminase elevation (2 cases), nerve root reactions (5 cases), fatigue and weight loss (1 case). The incidence of serious adverse reactions was 4, including grade 4-5 poor hematology (2 cases), grade 4 nerve root irritation (2 cases), and grade 4 elevated aminotransferase (1 case). In the dose climbing study, 4 patients were effectively treated and 7 were disease controlled. The survival time was ranged from 0.3 to 14.0 months and a median survival time was 3.8 months. The clinical study of pemetrexed intrathecal chemotherapy combined with radiotherapy showed that the treatment mode of 10 mg pemetrexed intrathecal chemotherapy once a week combined with synchronous involved area radiotherapy 40 Gy/4 weeks had a high safety and reactivity. The incidence of major adverse reactions was 52.9% (18/34), including hematologic adverse reactions (13 cases), transaminase elevation (10 cases), and nerve root reactions (4 cases). In study 2, the response rate was 67.6% (23/34), the disease control rate was 73.5% (25/34), the overall survival time was ranged from 0.3 to 16.6 months, the median survival time was 5.5 months, and the 1-year survival rate was 21.6%. Clinical response, improvement of neurological dysfunction, completion of concurrent therapy and subsequent systemic therapy were associated with the overall survival (all P<0.05). Conclusions: Pemetrexed is suitable for the intrathecal chemotherapy with a high safety and efficacy. The recommended administration regimen was IP at 10 mg on the schedule of once or twice per week. Hematological toxicity is the main factor affecting the implementation of IP. Vitamin supplement can effectively control the occurrence of hematological toxicity.

Zanthoxylum bungeanum Seed Oil Elicits Autophagy and Apoptosis in Human Laryngeal Tumor Cells via PI3K/AKT/mTOR Signaling Pathway.

BACKGROUND: Zanthoxylum bungeanum seed oil (ZBSO) is the main extract of the edible drug Zanthoxylum bungeanum seeds. Recent reports have proved that it has a significant cytotoxic effect on various cancer cells. However, systematic investigation on the role of ZBSO in laryngeal carcinoma (LC) is rare. OBJECTIVE: The aim of the study was to reveal the function of ZBSO on human laryngeal squamous carcinoma cells (Hep-2) and to elucidate its underlying mechanism. METHODS: In this study, the chemical composition analysis of ZBSO was done using Ultra Performance Liquid Chromatography (UPLC), and the anti-tumor effect of ZBSO on Hep-2 cells was evaluated by cell proliferation, apoptosis and cell cycle experiments. qRT-PCR, immunohistochemistry (IHC) and Western blotting were used for mechanistic investigation at the molecular level. RESULTS: The main compound of ZBSO was identified as polyunsaturated fatty acids. Furthermore, as compared to normal cells, significant inhibitory activities of ZBSO were observed on Hep-2 cells with dose- and timedependency, which induced apoptosis, blocked cell cycle at the S phase, and inhibited cell proliferation. In addition, IHC results showed a difference in the level of protein expression of ZBSO-induced autophagy-related markers. At last, Western blotting results indicated that ZBSO could inhibit the expression and phosphorylation levels of PI3K/AKT/mTOR protein. CONCLUSION: The anti-LC effect of ZBSO might be intimately associated with the induction of autophagy and the inhibition of the PI3K/AKT/mTOR signaling pathway. ZBSO may be a potential anti-laryngocarcinoma agent.

Health Benefits of Culinary Herbs and Spices.

Spices and herbs have been in use for centuries both for culinary and medicinal purposes. Spices not only enhance the flavor, aroma, and color of food and beverages, but they can also protect from acute and chronic diseases. More Americans are considering the use of spices and herbs for medicinal and therapeutic/remedy use, especially for various chronic conditions. There is now ample evidence that spices and herbs possess antioxidant, anti-inflammatory, antitumorigenic, anticarcinogenic, and glucose- and cholesterol-lowering activities as well as properties that affect cognition and mood. Research over the past decade has reported on the diverse range of health properties that they possess via their bioactive constituents, including sulfur-containing compounds, tannins, alkaloids, phenolic diterpenes, and vitamins, especially flavonoids and polyphenols. Spices and herbs such as clove, rosemary, sage, oregano, and cinnamon are excellent sources of antioxidants with their high content of phenolic compounds. It is evident that frequent consumption of spicy foods was also linked to a lower risk of death from cancer and ischemic heart and respiratory system diseases. However, the actual role of spices and herbs in the maintenance of health, specifically with regards to protecting against the development of chronic, noncommunicable diseases, is currently unclear. This review highlights potential health benefits of commonly used spices and herbs such as chili pepper, cinnamon, ginger, black pepper, turmeric, fenugreek, rosemary, and garlic.

[Effect of continuous femoral nerve block combined with periarticular local infiltration analgesia on early operative functional recovery after total knee arthroplasty: a randomized double-blind controlled study].

OBJECTIVE: To investigate the effects of early rehabilitation training after total knee arthroplasty surgery by continuous femoral nerve block (CFNB) with or without periarticular local infiltration analgesia (PLIA). METHODS: In this randomized, double-blind, controlled study, 100 patients under-going primary unilateral total knee arthroplasty in patients with knee osteoarthritis were enrolled. All the patients received CFNB for postoperative analgesia before combined spinal epidural anesthesia. They were randomly divided into 2 groups (n=50 each): CFNB group, CFNB combined with PLIA group (PLIA group). Group PLIA received periarticular local infiltration analgesia with 20 mL ropivacaine (5 g/L), while the equal volume of normal saline was used instead of ropivacaine in group CFNB. Postoperative pain during rest and passive exercises including front and rear portions of knees, the time of ability to perform an active straight leg raise, the time of ability to reach 90° knee flexion, and preoperative and postoperative hospital for special surgery knee score (HSS) were evaluated. RESULTS: Compared with group CFNB, the visual analogue scores (VAS) of front of knees at rest time in group PLIA had no significant difference (P>0.05); there were significant differences at 4, 8, 12, 24 h postoperation in portions of knees at rest time (P<0.05); the VAS had significant differences at 24 h in passive exercises of knees (P<0.05); the VAS had significant differences at 12, 24 h in portions of knees at passive exercises of the knees (P<0.05); the time of ability to perform an active straight leg raise had significant differences in the two groups (P<0.05). CONCLUSION: Compared with CFNB postoperative analgesia alone, CFNB with PLIA could relieve rest pain and pain during passive movement after total knee arthroplasty. CFNB with PLIA could shorten the time to perform an active straight leg raise and the time of ability to reach 90° knee flexion. And so some patients could improve postoperative rehabilitation training.

Wogonoside exerts growth-suppressive effects against T acute lymphoblastic leukemia through the STAT3 pathway.

Wogonoside is the main flavonoid of the traditional Chinese medicinal herb Scutellaria baicalensis Georgi and has been found to induce growth suppression in myelogenous leukemia cells. However, its activity in T acute lymphoblastic leukemia (T-ALL) is still unclear. In this study, T-ALL cell lines MOLT-3 and Jurkat were exposed to different concentrations of wogonoside for 48 h, and cell viability, cell cycle distribution, and apoptosis were measured. The involvement of signal transducers and activators of transcription 3 (STAT3) signaling in the activity of wogonoside was checked. The in vivo effect of wogonoside on T-ALL growth was investigated in a xenograft mouse model. Wogonoside significantly inhibited the viability of MOLT-3 and Jurkat cells, with the IC50 (the half maximal concentration) of 68.5 ± 3.8 and 52.6 ± 4.3 µM, respectively. However, healthy T lymphocytes were unaffected. Wogonoside-treated Jurkat cells exhibited a G1-phase cell cycle arrest and significant apoptosis, which was coupled with inactivation of STAT3 signaling. Overexpression of constitutively active STAT3 reversed wogonoside-mediated growth suppression and apoptosis and restored the expression of cyclin D1, Mcl-1, and Bcl-xL. In vivo studies demonstrated that wogonoside retarded tumor growth and suppressed STAT3 phosphorylation in Jurkat xenografts. In conclusion, wogonoside suppresses the growth of T-ALL through the STAT3 pathway and may have therapeutic benefits in this disease.

Decreased functional connectivity between the mediodorsal thalamus and default mode network in patients with disorders of consciousness.

BACKGROUND: Interactions between the thalamus and the cortex play an important role in consciousness. The thalamus as a homogenous structure is less strongly connected with the default mode network (DMN) in patients with disorders of consciousness (DOC), but the roles of specific thalamic nuclei are not clear. The purpose of this study was to investigate the functional connectivity between individual thalamic nuclei and the DMN in DOC patients. METHODS: Nine DOC patients and nine age-matched healthy controls were scanned with functional magnetic resonance imaging (fMRI) at resting state. Data-driven independent component analysis and hypothesis-driven region of interest-based correlation analysis were performed. RESULTS: In comparison with healthy controls, DOC patients had significantly decreased functional connectivity between the mediodorsal thalamus and brain areas within the DMN, including the medial prefrontal cortex and posterior cingulate cortex/precuneus. Patients and controls did not show significant differences in functional connectivity in other thalamic nuclei. CONCLUSION: Our results suggest that functional connections between the mediodorsal thalamus and the DMN may play important roles in the pathogenesis of DOC.

Syzygium aromaticum L. (Clove) extract regulates energy metabolism in myocytes.

The prevalence of metabolic syndrome and type 2 diabetes is increasing worldwide. Herbs and spices have been used for the treatment of diabetes for centuries in folk medicine. Syzygium aromaticum L. (Clove) extracts (SE) have been shown to perform comparably to insulin by significantly reducing blood glucose levels in animal models; however, the mechanisms are not well understood. We investigated the effects of clove on metabolism in C2C12 myocytes and demonstrated that SE significantly increases glucose consumption. The phosphorylation of AMP-activated protein kinase (AMPK), as well as its substrate, acetyl-CoA carboxylase (ACC) was increased by SE treatment. SE also transcriptionally regulates genes involved in metabolism, including sirtuin 1 (SIRT1) and PPARγ coactivator 1α (PGC1α). Nicotinamide, an SIRT1 inhibitor, diminished SE's effects on glucose consumption. Furthermore, treatment with SE dose-dependently increases muscle glycolysis and mitochondrial spare respiratory capacity. Overall, our study suggests that SE has the potential to increase muscle glycolysis and mitochondria function by activating both AMPK and SIRT1 pathways.

Difference between ferritin genes overexpressing in transgenic tobacco.

With the development of molecular biology techniques, intron was known as playing an imperative role in gene's expression and regulation. Transgenic tobacco IN lines overexpressing InFer1 gene and NT lines overexpressing NtFer1 cDNA gene were obtained, and the exogenous gene expression were confirmed by molecular test. Then for iron content of transgenic tobacco lines and non-transformants as a physiological indicator in status of different iron concentration were measured, and results indicated that the iron content of transgenic tobacco was more than that of non-transformants. In high Fe (II) condition, the NT lines showed higher level in plant height, fresh weight and iron content then that of IN lines, while NT lines showed lower in Malondialdehyde content then IN lines. In soil condition, IN lines showed higher level in plant height, fresh weight, chlorophyll, photosynthesis rate, iron content then that of NT lines. It indicates that intron could play a vital role for improved protective enzyme activity level while reducing reactive oxygen damage and also could help to inhibit the absorption of aborting iron.

Transcutaneous electric acupoint stimulation reduces intra-operative remifentanil consumption and alleviates postoperative side-effects in patients undergoing sinusotomy: a prospective, randomized, placebo-controlled trial.

BACKGROUND: Although opioids are widely used as analgesics in general anaesthesia, they have unpleasant side-effects and can delay postoperative recovery. Acupuncture and related techniques are effective for acute and chronic pain, and reduces some side-effects. We assessed the effect of transcutaneous electric acupoint stimulation (TEAS) on intra-operative remifentanil consumption and the incidences of anaesthesia-related side-effects. METHODS: Sixty patients undergoing sinusotomy were randomly assigned to TEAS or control group. TEAS consisted of 30 min of stimulation (6-9 mA, 2/10 Hz) on the Hegu (LI4), Neiguan (PC6), and Zusanli (ST36) before anaesthesia. The patients in the control group had the electrodes applied, but received no stimulation. Bispectral index was used to monitor the depth of anaesthesia. Perioperative haemodynamics were recorded, and peripheral blood samples were collected to measure the levels of mediators of surgical stress. The primary end point was intraoperative remifentanil consumption and the secondary endpoints were recovery quality and anaesthesia-related side-effects. RESULTS: Patients in the TEAS group required 39% less remifentanil during surgery than controls [0.0907 (SD 0.026) µg kg(-1) min(-1) vs 0.051 (0.018) µg kg(-1) min(-1)]. There were no differences in intra-operative haemodynamics or surgical stress between groups. However, the time to extubation and recall in the control group was 16.8 (6.8) min and 23.0 (5.0) min, respectively, significantly longer than that in the TEAS group (P<0.01). TEAS also decreased the incidence of dizziness and pruritus within the first 24 h after surgery (P<0.01). CONCLUSION: The use of TEAS significantly reduced intra-operative remifentanil consumption and alleviated postoperative side-effects in patients undergoing sinusotomy. CLINICAL TRIAL REGISTRATION: The trial was registered at clinicaltrials.gov (NCT01700855).

Rosemary (Rosmarinus officinalis L.) extract regulates glucose and lipid metabolism by activating AMPK and PPAR pathways in HepG2 cells.

An epidemic of metabolic disorders such as obesity and diabetes is rising dramatically. Using natural products as potential preventive and therapeutic interventions for these disorders has drawn worldwide attention. Rosemary has been shown to lower blood glucose and cholesterol levels and mitigate weight gain in several in vivo studies. However, the mechanisms are essentially unknown. We investigated the effects of rosemary extract on metabolism and demonstrated that rosemary extract significantly increased glucose consumption in HepG2 cells. The phosphorylation of AMP-activated protein kinase (AMPK) and its substrate, acetyl-CoA carboxylase (ACC), was increased by rosemary extract. Rosemary extract also transcriptionally regulated the genes involved in metabolism, including SIRT1, PPARγ coactivator 1α (PGC1α), glucose-6-phosphatase (G6Pase), ACC, and low-density lipoprotein receptor (LDLR). Furthermore, the PPARγ-specific antagonist GW9662 diminished rosemary's effects on glucose consumption. Overall, our study suggested that rosemary potentially increases liver glycolysis and fatty acid oxidation by activating AMPK and PPAR pathways.

Fatty acid composition of adipose tissue and muscle from Jersey steers was affected by finishing diet and tissue location.

To determine the impacts of finishing diet and tissue type and location on fatty acid composition and palatability of Jersey beef, twenty steers were assigned to a factorial treatment design with initial weight (Light vs. Heavy) and finishing diet (70 vs. 85% concentrate) as treatments. Ribeye steaks were collected for sensory evaluation. Muscle, seam and subcutaneous (s.c.) fat from steaks, kidney fat (KF) and omental fat (OMF) were collected for fatty acid analysis. Initial weight and finishing diet had little impact on beef palatability. The 85% concentrate decreased polyunsaturated fatty acids (PUFA) in muscle and increased trans fatty acids in all tissues (P<0.05). The monounsaturated:saturated fatty acid ratio (MUFA:SFA) was highest in s.c. fat, intermediate in muscle and seam fat, and lowest in KF and OMF. The PUFA:SFA was highest in muscle, intermediate in s.c. and seam fat, and lowest in KF and OMF. Fatty acid composition differed greatly among tissues and the lower concentrate diet increased omega-3 and PUFA percentages in muscle.

Effects of two in-office bleaching agents with different pH on the structure of human enamel: an in situ and in vitro study.

This study evaluated the effects of two in-office bleaching agents (Beyond and Opalescence Boost) with different pH on the structure and mechanical properties of human enamel in vitro and in situ. One hundred and eight enamel slabs were obtained from freshly extracted premolars. The specimens were randomly distributed into nine groups (n=12), and the human saliva (HS) in the volunteers' oral cavities was used to simulate the in situ condition: Beyond + HS, Opalescence Boost (O-Boost) + HS, Control + HS, Beyond + artificial saliva (AS), O-Boost + AS, Control + AS, Beyond + distilled water (DW), O-Boost + DW, and Control + DW. The bleaching treatments were performed on the first and eighth day, and the total bleaching time was 90 minutes. Baseline and final surface roughness (RMS), surface morphology, microhardness, and fracture toughness (FT) were measured before the treatment and on the fifteenth day, respectively. Compared with control groups, surface alterations on enamel were found in the Beyond + AS and Beyond + DW groups under atomic force microscopy evaluation. Two-way analysis of variance and Tukey test revealed that the RMS showed significant intergroup differences for both storage condition and bleaching agent, whereas microhardness and FT revealed no significant alteration. The results indicated that in-office bleaching agents with low pH values could induce enamel morphology alterations under in vitro conditions. The presence of natural HS could eliminate the demineralization effect caused by low pH.

Effects of transcranial direct current stimulation on hemichannel pannexin-1 and neural plasticity in rat model of cerebral infarction.

The aim of this study was to investigate the effects of transcranial direct current stimulation (TDCS) on hemichannel pannexin-1 (PX1) in cortical neurons and neural plasticity, and explore the optimal time window of TDCS therapy after stroke. Adult male Sprague-Dawley rats (n=90) were randomly assigned to sham operation, middle cerebral artery occlusion (MCAO), and TDCS groups, and underwent sham operation, unilateral middle cerebral artery (MCA) electrocoagulation, and unilateral MCA electrocoagulation plus TDCS (daily anodal and cathodal 10 Hz, 0.1 mA TDCS for 30 min beginning day 1 after stroke), respectively. Motor function was assessed using the beam walking test (BWT), and density of dendritic spines (DS) and PX1 mRNA expression were compared among groups on days 3, 7, and 14 after stroke. Effects of PX1 blockage on DS in hippocampal neurons after hypoxia-ischemia were observed. TDCS significantly improved motor function on days 7 and 14 after stroke as indicated by reduced BWT scores compared with the MCAO group. The density of DS was decreased after stroke; the TDCS group had increased DS density compared with the MCAO group on days 3, 7, and 14 (all P<0.0001). Cerebral infarction induced increased PX1 mRNA expression on days 3, 7, and 14 (P<0.0001), and the peak PX1 mRNA expression was observed on day 7. TDCS did not decrease the up-regulated PX1 mRNA expression after stroke on day 3, but did reduce the increased post-stroke PX1 mRNA expression on days 7 and 14 (P<0.0001). TDCS increased the DS density after stroke, indicating that it may promote neural plasticity after stroke. TDCS intervention from day 7 to day 14 after stroke demonstrated motor function improvement and can down-regulate the elevated PX1 mRNA expression after stroke.

The dentine remineralization activity of a desensitizing bioactive glass-containing toothpaste: an in vitro study.

BACKGROUND: Dentine hypersensitivity occurs easily on exposed dentine. This study aimed to evaluate the effectiveness of a novel bioactive glass-containing toothpaste on dentine permeability and remineralization. METHODS: Thirty dentine discs were divided into three groups of 10 specimens each. The groups corresponded to the following brushing treatments: no brush, distilled water, and bioactive glass-containing toothpaste (Novamin). The toothpaste was applied twice a day for 7 days. Dentine permeability was measured after ethylene-diamine-tetraacetic acid (EDTA) etching, initial application, 3-day application, 7-day application and citric acid challenge, respectively. The dentine morphology was investigated using scanning electron microscopy (SEM). Attenuated total reflection Fourier transform infrared (ATR/FTIR) spectroscopy was performed to monitor the mineral variation on demineralized dentine. Qualitative information of elemental variation before and after treatments on completely demineralized dentine was detected by energy dispersive X-ray (EDX) analysis. RESULTS: The bioactive glass-containing toothpaste significantly reduced dentine permeability after the 7-day treatment and showed, under SEM, excellent resistance to acid challenge compared to the other groups. ATR/FTIR and EDX revealed increased mineral content after treatment with Novamin. CONCLUSIONS: As the innovative bioactive glass-containing toothpaste occlude dentinal tubules and resist acid challenge, it may be useful for the treatment of dentine hypersensitivity and dentine remineralization.

Omega-3 fatty acids affected human perception of ground beef negatively.

The objective was to determine the impact of increasing levels of Eicosapentaenoic acid (EPA; C20:5n3) and Docosahexaenoic acid (DHA; C22:6n3) on beef palatability. Two commercial supplements of EPA and DHA were added to 85% lean ground beef patties (176.2 ± 3.76 g) with different levels (0, 0.3, 0.4, 0.5, 0.6, 0.7, and 1% as-is). Olive oil was added so that all patties contained 1% added lipid. A control treatment was also prepared with no supplement or olive oil. Sensory evaluation and fatty acid analysis was conducted. Ground beef flavor decreased linearly (P<0.001) with increasing levels of EPA and DHA. Off-aroma and off-flavor increased linearly and then plateaued with increasing levels of EPA (P<0.0001). In conclusion, EPA had a greater negative impact on beef palatability than DHA. Also, the panelists were more sensitive to EPA in off-flavor perception than off-aroma.

Change in taste preference in undernourished elderly hospitalized subjects during periods of infection and convalescence.

AIM: To determine the impact of taste pleasure supplements on modifications of food intake in hospitalized frail elderly patients. METHODS: Thirty hospitalized frail elderly patients tasted different formulas of a high-protein coffee supplement: -supplement C, commercial version; - supplement CA with artificial coffee flavor; - supplement CS with sucrose and - supplement CAS with sucrose and artificial coffee flavor. The preference for the supplements was analyzed by the Friedman test followed by a post hoc Tukey's test. The food intakes in each period were compared by repeated ANOVA and the food intakes of the two periods were compared using Student's t test. All measurements were made during periods of infection and convalescence. RESULTS: The supplements CAS and CS were significantly more appreciated than the current commercial version C (P < .05). The patients could be classified into two groups: consumers (consuming the supplements) and nonconsumers (just tasting the supplements). Taking supplements can increase the total energy intake for consumers (P < .01), especially during periods of infection; no modification was observed in the non-consumers. CONCLUSION: The use of supplements to increase sensory pleasure can be one feasible way to increase energy intake in hospitalized elderly patients with an infectious disease.

Model-based optimisation of the biological performance of a sidestream MBR.

A model-based optimisation of the operation in view of the biological performance in terms of nitrogen (N) and phosphorus (P) removal of a pilot-scale side-stream MBR has been performed by means of a two-tier scenario analysis. The methodology uses two different scenario analyses to simulate the effect of three degrees of freedom in the MBR system: (1) DO set-point in the aerobic reactor, (2) sludge residence time and (3) internal recirculation rate. The scenarios are simulated using a calibrated ASM2d MBR model. Effluent quality, in terms of nitrate, ammonia and phosphate, is used to select the best scenario. It proved to be a compromise between nitrogen and phosphorus removal as these are linked. A 42% reduction in ammonium and a 32% reduction in nitrate concentration were achieved. Phosphate removal is partly sacrificed (39% increase) compared to the standard operation.

The 44 kDa Pim-1 kinase directly interacts with tyrosine kinase Etk/BMX and protects human prostate cancer cells from apoptosis induced by chemotherapeutic drugs.

Protein kinase Pim-1 has been implicated in the development of hematopoietic and prostatic malignancies. Here, we present the evidence that two isoforms, the 44 and 33 kDa Pim-1, are expressed in all human prostate cancer cell lines examined. The subcellular localization of human 44 kDa Pim-1 is primarily on the plasma membrane, while the 33 kDa isoform is present in both the cytosol and nucleus in PCA cells. The 44 kDa Pim-1 contains the proline-rich motif at the N-terminus and directly binds to the SH3 domain of tyrosine kinase Etk. Such interaction leads to the activation of Etk kinase activity possibly by competing with the tumor suppressor p53. This is corroborated by the fact that overexpression of the 44 kDa Pim-1 in prostate cancer cells confers the resistance to chemotherapeutic drugs. Our results suggest that these two isoforms of Pim-1 kinase may regulate distinct substrates and the 44 kDa Pim-1 may play a more prominent role in drug resistance in prostate cancer cells.

A novel optical biosensor format for the detection of clinically relevant TP53 mutations.

The TP53 gene has been the subject of intense research since the realisation that inactivation of this gene is common to most cancer types. Numerous publications have linked TP53 mutations in general or at specific locations to patient prognosis and therapy response. The findings of many studies using general approaches such as immunohistochemistry or sequencing are contradictory. However, the detection of specific mutations, especially those occurring in the structurally important L2 and L3 zinc binding domains, which are the most common sites of TP53 mutations, have been linked to patient prognosis and more strongly to radiotherapy and chemotherapy resistance in several major cancers. In this study, the TI-SPR-1 surface plasmon resonance system and Texas Instruments Spreeta chips were used to develop a DNA biosensor based on thiolated probes complementary to these domains. The sensors were able to detect these mutations in both oligonucleotides and PCR products with normal and mutant TP53 DNA, but the difference in hybridisation signal was small. Preliminary experiments to enhance the signal using Escherichia coli mismatch repair proteins, MutS and single strand binding protein were carried out. It was found that MutS was unable to bind to mismatch oligonucleotides, but single strand binding protein was able to bind to single stranded probes, which had not hybridised to the target, resulting in a three-fold increase in the sensitivity of the biosensor. While further work needs to be carried out to optimise the system, these preliminary experiments indicate that the TI-SPR-1 can be used for the detection of clinically relevant mutations in the TP53 gene and that the sensitivity can be increased significantly using single strand binding protein. This system has a number of advantages over current mutation detection technologies, including lower cost, ease of sensor preparation and measurement procedures, technical simplicity and increased speed due to the lack of need for gel electrophoresis.