Germline mutations of the PTEN gene in Cowden disease, an inherited breast and thyroid cancer syndrome

Cowden disease (CD) is an autosomal dominant cancer predisposition syndrome associated with an elevated risk for tumours of the breast, thyroid and skin. Lhermitte-Duclos disease (LDD) cosegregates with a subset of CD families and is associated with macrocephaly, ataxia and dysplastic cerebellar gangliocytomatosis. The common feature of these diseases is a predisposition to hamartomas, benign tumours containing differentiated but disorganized cells indigenous to the tissue of origin. Linkage analysis has determined that a single locus within chromosome 10q23 is likely to be responsible for both of these diseases. A candidate tumour suppressor gene (PTEN) within this region is mutated in sporadic brain, breast and prostate cancer. Another group has independently isolated the same gene, termed MMAC1, and also found somatic mutations throughout the gene in advanced sporadic cancers. Mutational analysis of PTEN in CD kindreds has identified germline mutations in four of five families. We found nonsense and missense mutations that are predicted to disrupt the protein tyrosine/dual-specificity phosphatase domain of this gene. Thus, PTEN appears to behave as a tumour suppressor gene in the germline. Our data also imply that PTEN may play a role in organizing the relationship of different cell types within an organ during development.

Crystal structure of rhodopsin bound to arrestin by femtosecond X-ray laser

G-protein-coupled receptors (GPCRs) signal primarily through G proteins or arrestins. Arrestin binding to GPCRs blocks G protein interaction and redirects signalling to numerous G-protein-independent pathways. Here we report the crystal structure of a constitutively active form of human rhodopsin bound to a pre-activated form of the mouse visual arrestin, determined by serial femtosecond X-ray laser crystallography. Together with extensive biochemical and mutagenesis data, the structure reveals an overall architecture of the rhodopsin-arrestin assembly in which rhodopsin uses distinct structural elements, including transmembrane helix 7 and helix 8, to recruit arrestin. Correspondingly, arrestin adopts the pre-activated conformation, with a ∼20° rotation between the amino and carboxy domains, which opens up a cleft in arrestin to accommodate a short helix formed by the second intracellular loop of rhodopsin. This structure provides a basis for understanding GPCR-mediated arrestin-biased signalling and demonstrates the power of X-ray lasers for advancing the frontiers of structural biology.

Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation

The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403 amino acid dual specificity phosphatase (protein tyrosine phosphatase; PTPase), was shown recently to play a broad role in human malignancy. Somatic PTEN deletions and mutations were observed in sporadic breast, brain, prostate and kidney cancer cell lines and in several primary tumours such as endometrial carcinomas, malignant melanoma and thyroid tumours. In addition, PTEN was identified as the susceptibility gene for two hamartoma syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD families and seven BZS families was screened for germline PTEN mutations. PTEN mutations were identified in 30 of 37 (81%) CD families, including missense and nonsense point mutations, deletions, insertions, a deletion/insertion and splice site mutations. These mutations were scattered over the entire length of PTEN , with the exception of the first, fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD mutations identified in this exon. Seven of 30 (23%) were within the core motif, the majority (five of seven) of which were missense mutations, possibly pointing to the functional significance of this region. Germline PTEN mutations were identified in four of seven (57%) BZS families studied. Interestingly, none of these mutations was observed in the PTPase core motif. It is also worthy of note that a single nonsense point mutation, R233X, was observed in the germline DNA from two unrelated CD families and one BZS family. Genotype-phenotype studies were not performed on this small group of BZS families. However, genotype-phenotype analysis inthe group of CD families revealed two possible associations worthy of follow-up in independent analyses. The first was an association noted in the group of CD families with breast disease. A correlation was observed between the presence/absence of a PTEN mutation and the type of breast involvement (unaffected versus benign versus malignant). Specifically and more directly, an association was also observed between the presence of a PTEN mutation and malignant breast disease. Secondly, there appeared to be an interdependent association between mutations upstream and within the PTPase core motif, the core motif containing the majority of missense mutations, and the involvement of all major organ systems (central nervous system, thyroid, breast, skin and gastrointestinal tract). However, these observations would need to be confirmed by studying a larger number of CD families.

Current development of biodegradable polymeric materials for biomedical applications

In the last half-century, the development of biodegradable polymeric materials for biomedical applications has advanced significantly. Biodegradable polymeric materials are favored in the development of therapeutic devices, including temporary implants and three-dimensional scaffolds for tissue engineering. Further advancements have occurred in the utilization of biodegradable polymeric materials for pharmacological applications such as delivery vehicles for controlled/sustained drug release. These applications require particular physicochemical, biological, and degradation properties of the materials to deliver effective therapy. As a result, a wide range of natural or synthetic polymers able to undergo hydrolytic or enzymatic degradation is being studied for biomedical applications. This review outlines the current development of biodegradable natural and synthetic polymeric materials for various biomedical applications, including tissue engineering, temporary implants, wound healing, and drug delivery.

DNA synthesis and repair genes RRM1 and ERCC1 in lung cancer

BACKGROUND

RRM1, the regulatory subunit of ribonucleotide reductase, is involved in carcinogenesis, tumor progression, and the response of non-small-cell lung cancer to treatment.

METHODS

We developed an automated quantitative determination of the RRM1 protein in routinely processed histologic specimens. In these specimens, we measured the expression of RRM1 and two other proteins that are relevant to non-small-cell lung cancer: the excision repair cross-complementation group 1 (ERCC1) protein and the phosphatase and tensin homologue (PTEN). We compared the results with the clinical outcomes in 187 patients with early-stage non-small-cell lung cancer who had received only surgical treatment.

RESULTS

RRM1 expression correlated with the expression of ERCC1 (P<0.001) but not with the expression of PTEN (P=0.37). The median disease-free survival exceeded 120 months in the group of patients with tumors that had high expression of RRM1 and was 54.5 months in the group with low expression of RRM1 (hazard ratio for disease progression or death in the high-expression group, 0.46; P=0.004). The overall survival was more than 120 months for patients with tumors with high expression of RRM1 and 60.2 months for those with low expression of RRM1 (hazard ratio for death, 0.61; P=0.02). Among these 187 patients, the survival advantage was limited to the 30% of patients with tumors that had a high expression of both RRM1 and ERCC1.

CONCLUSIONS

RRM1 and ERCC1 are determinants of survival after surgical treatment of early-stage, non-small-cell lung cancer.

Transfer RNA demethylase ALKBH3 promotes cancer progression via induction of tRNA-derived small RNAs

Transfer RNA is heavily modified and plays a central role in protein synthesis and cellular functions. Here we demonstrate that ALKBH3 is a 1-methyladenosine (m1A) and 3-methylcytidine (m3C) demethylase of tRNA. ALKBH3 can promote cancer cell proliferation, migration and invasion. In vivo study confirms the regulation effects of ALKBH3 on growth of tumor xenograft. The m1A demethylated tRNA is more sensitive to angiogenin (ANG) cleavage, followed by generating tRNA-derived small RNAs (tDRs) around the anticodon regions. tDRs are conserved among species, which strengthen the ribosome assembly and prevent apoptosis triggered by cytochrome c (Cyt c). Our discovery opens a potential and novel paradigm of tRNA demethylase, which regulates biological functions via generation of tDRs.

Infectivity, transmission, and pathology of human-isolated H7N9 influenza virus in ferrets and pigs

The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.

Glycosylation of CD44 negatively regulates its recognition of hyaluronan

Although CD44 is expressed on a wide variety of cell types, few of them use it to recognize the ligand hyaluronan (HA). A glycosylation-defective clone of Chinese hamster ovary cells (Lec 8) bound HA, demonstrating that complete processing of glycoproteins with addition of a full complement of sialic acid is not required. On the contrary, subsequent findings revealed that complex sugars on CD44 can actually inhibit ligand recognition. Two subclones of wild-type Chinese hamster ovary cells with similar amounts of surface CD44 were isolated on the basis of HA binding and found to differ with respect to CD44 size as well as staining with fluorescent lectins. Treatment of the nonbinding clone with tunicamycin reduced the size of the protein and allowed the cells to recognize HA via CD44. This function was also induced by treatment with deglycosylating enzymes (either a mixture of endoglycosidase F and N-glycosidase F or neuraminidase alone). A possible role for glycosylation in regulation of adhesion was then sought with a series of normal and transformed murine cells. Disruption of glycosylation or treatment with deglycosylating enzymes did not induce ligand binding in an interleukin 7-dependent pre-B cell line, and splenic B cells also appeared to be in an inactive state. Some normal B cells acquired the ability to recognize HA after stimulation with lipopolysaccharide or interleukin 5 and had distinctive surface characteristics (loss of immunoglobulin D and acquisition of CD43). An additional subset of activated cells might have been in a transitional state, because the cells bound ligand after neuraminidase treatment. The ligand-binding ability of a purified CD44-immunoglobulin fusion protein dramatically increased after neuraminidase treatment. Thus, differential glycosylation of this molecule is sufficient to influence its recognition function. Cell adhesion involving HA can be regulated by multiple mechanisms, one of which involves variable glycosylation of CD44.

MetMAb, the one-armed 5D5 anti-c-Met antibody, inhibits orthotopic pancreatic tumor growth and improves survival

The hepatocyte growth factor (HGF) and its receptor, c-Met, have been implicated in driving proliferation, invasion, and poor prognosis in pancreatic cancer. Here, we investigated the expression of HGF and c-Met in primary pancreatic cancers and described in vitro and in vivo models in which MetMAb, a monovalent antibody against c-Met, was evaluated. First, expression of HGF and MET mRNA was analyzed in 59 primary pancreatic cancers and 51 normal samples, showing that both factors are highly expressed in pancreatic cancer. We next examined HGF responsiveness in pancreatic cancer lines to select lines that proliferate in response to HGF. Based on these studies, two lines were selected for further in vivo model development: BxPC-3 (c-Met(+), HGF(-)) and KP4 (c-Met(+), HGF(+)) cells. As BxPC-3 cells are responsive to exogenous HGF, s.c. tumor xenografts were grown in a paracrine manner with purified human HGF provided by osmotic pumps, wherein MetMAb treatment significantly inhibited tumor growth. KP4 cells are autocrine for HGF and c-Met, and MetMAb strongly inhibited s.c. tumor growth. To better model pancreatic cancer and to enable long-term survival studies, an orthotopic model of KP4 was established. MetMAb significantly inhibited orthotopic KP4 tumor growth in 4-week studies monitored by ultrasound and also improved survival in 90-day studies. MetMAb significantly reduced c-Met phosphorylation in orthotopic KP4 tumors with a concomitant decrease in Ki-67 staining. These data suggest that the HGF/c-Met axis plays an important role in the progression of pancreatic cancer and that targeting c-Met therein may have therapeutic value.

Activated epidermal growth factor receptor-Stat-3 signaling promotes tumor survival in vivo in non-small cell lung cancer

PURPOSE

Signal transducers and activators of transcription 3 (Stat3), a member of the STAT family of transcription factors, regulates multiple oncogenic pathways, including pathways regulating tumor cell survival. We evaluated Stat3 activation in early stage non-small cell lung cancers (NSCLC) and how this relates to upstream epidermal growth factor receptor (EGFR) activation, tumor apoptosis, and prognosis.

EXPERIMENTAL DESIGN

High-density tissue microarrays using tissues from 176 surgically resected NSCLC were evaluated for expression of phosphorylated Stat3 (pStat3) and epidermal growth factor receptor (pEGFR) along with tumor apoptosis. Using NSCLC cell lines, we evaluated how pStat3 expression relates to EGFR mutations and sensitivity of cells to gefitinib.

RESULTS

We identified nuclear pStat3 expression in 54% of tumors. pStat3 expression was correlated with smaller tumors (P < 0.0001) and with limited smoking history (P = 0.02). We identified a trend toward higher pStat3 expression in adenocarcinomas compared with other tumor histology (P = 0.09). No relationship was found between pStat3 and prognosis following surgical resection. Importantly, we found a strong positive correlation between pEGFR expression and pStat3 expression (P <0.0001) and an inverse correlation between pStat3 and apoptosis (P = 0.01) consistent with less apoptosis in tumors expressing high amounts of pStat3. Cell lines with mutant EGFR have increased levels of pStat3 compared with cell lines without mutant EGFR and this correlates with their sensitivity to gefitinib. Finally, antisense-mediated knockdown of Stat3 induces apoptosis in EGFR mutant lung cancer cells.

CONCLUSIONS

Early-stage NSCLC tumors have activated EGFR-Stat3 signaling with low apoptosis. Our findings suggest that pStat3 expression may be helpful in identifying patients appropriate for treatment with EGFR tyrosine kinase inhibitors.

Establishment of two immortalized nasopharyngeal epithelial cell lines using SV40 large T and HPV16E6/E7 viral oncogenes

Nasopharyngeal carcinoma (NPC) is a common cancer in Southeast Asia, especially in southern China. One of the most striking features of this disease is its close relationship with Epstein-Barr Virus (EBV). However, to date there is no direct study on the mechanisms involved in the role of EBV in the tumorigenesis of NPC, largely due to lack of an experimental model. Available hypotheses on the association between EBV and NPC are generated from non-nasopharyngeal epithelial cell systems such as human keratinocytes or mouse epithelial cells, which may not truly represent the biological properties of nasopharyngeal epithelial (NP) cells. In this study, we report the establishment of two immortalized NP cell lines, NP69SV40T and NP39E6/E7, using SV40T and HPV16E6/E7 oncogenes. We found that NP60SV40T and NP39E6/E7 cell lines not only maintained many characteristics of normal NP cells (i.e. keratin profile and responsive to TGFbeta inhibition) but also highly responsive to one of the EBV encoded genes, LMP1. Comparative genome hybridization (CGH) analysis showed that these two cell lines contained multiple genetic alterations, some of which have been described in NPC. The immortalized NP cell lines are non-tumorigenic and exhibit anchorage-dependent growth. These cell lines may provide a possible cell model system for studying the mechanisms involved in the tumorigenesis of NPC.

The Impact of Dental Implant Surface Modifications on Osseointegration and Biofilm Formation

Implant surface design has evolved to meet oral rehabilitation challenges in both healthy and compromised bone. For example, to conquer the most common dental implant-related complications, peri-implantitis, and subsequent implant loss, implant surfaces have been modified to introduce desired properties to a dental implant and thus increase the implant success rate and expand their indications. Until now, a diversity of implant surface modifications, including different physical, chemical, and biological techniques, have been applied to a broad range of materials, such as titanium, zirconia, and polyether ether ketone, to achieve these goals. Ideal modifications enhance the interaction between the implant's surface and its surrounding bone which will facilitate osseointegration while minimizing the bacterial colonization to reduce the risk of biofilm formation. This review article aims to comprehensively discuss currently available implant surface modifications commonly used in implantology in terms of their impact on osseointegration and biofilm formation, which is critical for clinicians to choose the most suitable materials to improve the success and survival of implantation.

Sialyl Lewisx-containing oligosaccharide attenuates myocardial reperfusion injury in cats

Neutrophil (PMN) adhesion to the vascular endothelium is an important mechanism of myocardial reperfusion injury. The adhesion process is initially mediated by selectins (e.g., P- and L-selectin), and monoclonal antibodies directed against these adhesion molecules exert cardioprotective activity in ischemia/reperfusion models. The counterreceptors for these selectins are thought to be carbohydrate-containing moieties. In this connection, we studied the effect of a soluble sialyl Lewisx-containing oligosaccharide (SLex-OS) on PMN-endothelial interactions in a feline model of myocardial ischemia/reperfusion (MI/R). SLex-OS (10 mg/kg), administered 10 min before R, significantly reduced myocardial necrosis compared with its vehicle 270 min after reperfusion (6 +/- 1% vs. 35 +/- 4% of area at risk, P < 0.01). The cardioprotection was confirmed by significantly lower plasma creatine kinase activities in SLex-OS vs. vehicle-treated cats (P < 0.01). Cardiac contractility (dP/dt max) of cats receiving SLex-OS was significantly preserved after 270 min of R (97 +/- 2% vs. 78 +/- 5% of initial, P < 0.01). Furthermore, endothelium-dependent relaxation to acetylcholine in coronary artery rings isolated from MI/R cats treated with SLex-OS was significantly preserved (73 +/- 7% vs. 22 +/- 6% vasorelaxation, P < 0.01). In vitro PMN adherence to coronary vascular endothelium after 270 min of R was significantly attenuated in the SLex-OS-treated group compared with the vehicle group (14 +/- 5 vs. 91 +/- 12 PMN/mm2, P < 0.01). Our results indicate that a SLex-OS is cardioprotective and preserves coronary endothelial function after MI/R, indicating an important role of sialyl Lewisx in PMN accumulation, endothelial dysfunction, and myocardial injury in myocardial ischemia/reperfusion.

Development of optimal bicistronic lentiviral vectors facilitates high-level TCR gene expression and robust tumor cell recognition

In human gene therapy applications, lentiviral vectors may have advantages over gamma-retroviral vectors in several areas, including the ability to transduce nondividing cells, resistance to gene silencing and a potentially safer integration site profile. However, unlike gamma-retroviral vectors it has been problematic to drive the expression of multiple genes efficiently and coordinately with approaches such as internal ribosome entry sites or dual promoters. Using different 2A peptides, lentiviral vectors expressing two-gene T-cell receptors directed against the melanoma differentiation antigens gp100 and MART-1 were constructed. We demonstrated that addition of amino-acid spacer sequences (GSG or SGSG) before the 2A sequence is a prerequisite for efficient synthesis of biologically active T-cell receptors and that addition of a furin cleavage site followed by a V5 peptide tag yielded optimal T-cell receptor gene expression. Furthermore, we determined that the furin cleavage site was recognized in lymphocytes and accounted for removal of residual 2A peptides at the post-translational level with an efficiency of 20-30%, which could not be increased by addition of multiple furin cleavage sites. The novel bicistronic lentiviral vector developed herein afforded robust anti-melanoma activities to engineered peripheral blood lymphocytes, including cytokine secretion, cell proliferation and lytic activity. Such optimal vectors may have immediate applications in cancer gene therapy.

Spectinamides: a new class of semisynthetic antituberculosis agents that overcome native drug efflux

Although the classical antibiotic spectinomycin is a potent bacterial protein synthesis inhibitor, poor antimycobacterial activity limits its clinical application for treating tuberculosis. Using structure-based design, we generated a new semisynthetic series of spectinomycin analogs with selective ribosomal inhibition and excellent narrow-spectrum antitubercular activity. In multiple murine infection models, these spectinamides were well tolerated, significantly reduced lung mycobacterial burden and increased survival. In vitro studies demonstrated a lack of cross resistance with existing tuberculosis therapeutics, activity against multidrug-resistant (MDR) and extensively drug-resistant tuberculosis and an excellent pharmacological profile. Key to their potent antitubercular properties was their structural modification to evade the Rv1258c efflux pump, which is upregulated in MDR strains and is implicated in macrophage-induced drug tolerance. The antitubercular efficacy of spectinamides demonstrates that synthetic modifications to classical antibiotics can overcome the challenge of intrinsic efflux pump-mediated resistance and expands opportunities for target-based tuberculosis drug discovery.

The human OGG1 DNA repair enzyme and its association with orolaryngeal cancer risk

The human OGG1 (hOGG1) gene encodes a DNA glycosylase that is involved in the excision repair of 8-hydroxy-2'-deoxyguanine (8-OH-dG) from oxidatively-damaged DNA. To determine whether hOGG1 plays a role in risk for orolaryngeal cancer, we screened normal orolaryngeal tissue specimens for hOGG1 expression and assessed the role of the hOGG1 Ser326Cys polymorphism in risk for orolaryngeal cancer. hOGG1 expression was determined by reverse transcription-polymerase chain reaction of total RNA from aerodigestive tract tissues, and hOGG1 genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism analysis of buccal cell DNA isolated from 169 Caucasian orolaryngeal cancer cases and 338 race-, sex- and age-matched controls. hOGG1 mRNA was detected in all aerodigestive tract tissues tested including tonsil, tongue, floor of mouth, larynx and esophagus. Significantly increased risk for orolaryngeal cancer was observed for both the hOGG1 326(Ser)/326(Cys) (odds ratio [OR] = 1.6, 95% confidence interval [CI] = 1.04-2.6) and hOGG1 326(Cys)/326(Cys) (OR = 4.1, 95% CI = 1.3-13) genotypes. Although no significant difference in risk for orolaryngeal cancer was observed for hOGG1 genotypes in never-smokers, increased risk for orolaryngeal cancer was observed for subjects with the homozygous polymorphic hOGG1 326(Cys)/326(Cys) genotype in smokers (>100 cigarettes lifetime; OR = 4.8, 95% CI = 1.3-18). Similarly, although no association was observed in never drinkers of alcohol, significantly increased risk was observed for the hOGG1 326(Cys)/326(Cys) genotype in alcohol drinkers (>1 shot/week; OR = 6.9, 95% CI = 1.6-29). These results suggest that hOGG1 may play an important role in the repair of 8-OH-dG adducts in the aerodigestive tract and that the hOGG1 Ser326Cys polymorphism plays an important role in risk for smoking- and alcohol-related orolaryngeal cancer.

Cobalt chloride induces PC12 cells apoptosis through reactive oxygen species and accompanied by AP-1 activation

Reactive oxygen species (ROS) are supposed to play an important role in hypoxia- and ischemia/reperfusion-mediated neuronal injury with the characteristics of apoptosis. There are many reports showing that cobalt chloride (CoCl(2)) could mimic the hypoxic responses in some aspects including production of ROS in cultured cells. The cytotoxicity of CoCl(2) and its molecular mechanisms have yet to be elucidated. We report that CoCl(2) triggered neuronal PC12 cells apoptosis in a dose- and time-dependent manner. Apoptosis was demonstrated by morphological changes and DNA fragmentation, and was dependent on macromolecular synthesis. Apoptosis was also confirmed by the decrease of the expression of Bcl-X(L). To our knowledge, this is the first documentation of the apoptotic induction of CoCl(2) on PC12 cells. Furthermore, ROS production in PC12 cells was increased during CoCl(2) treatment. Antioxidants, which could inhibit ROS production, significantly blocked CoCl(2)-induced apoptosis, suggesting that apoptosis is mediated by ROS production. We also observed a significant increase of the DNA-binding activity of AP-1 in response to CoCl(2) and this increase was blocked by antioxidants, showing that CoCl(2)-induced apoptosis is accompanied by ROS-activated AP-1. CoCl(2)-treated PC12 cells may serve as an in vitro model for studies of molecular mechanisms in ROS-linked neuronal disorders.

DTI correlates of distinct cognitive impairments in Parkinson's disease

The spectrum of cognitive symptoms in Parkinson's disease (PD) can span various domains, including executive function, language, attention, memory, and visuospatial skills. These symptoms may be attributable to the degradation of projection fibers associated with the underlying neurodegenerative process. The primary purpose of this study is to find microstructural correlates of impairments across these cognitive domains in PD using diffusion tensor imaging (DTI). Sixteen patients with PD with comprehensive neuropsychological evaluation and DTI data were retrospectively studied. Fractional anisotropy (FA) and mean diffusivity (MD) were assessed using regions-of-interest (ROI) analysis and confirmed with a voxel-based approach. Executive function directly correlated with FA and inversely correlated with MD in mostly frontal white matter tracts, especially the anterior limb of the internal capsule and genu of the corpus callosum. Likewise, language and attentional performance demonstrated correlations with DTI parameters in the frontal regions, but the attention domain additionally recruited regions widespread throughout the brain, with the most significant correlation identified in cingulate gyrus (cingulum). Lastly, memory impairment mainly involved MD alterations within the fornix. No significant correlations were found between visuospatial skills and DTI measures. Despite some overlap, unique patterns of white matter diffusivity underlie impairments in distinct cognitive domains in patients with PD. DTI combined with neurocognitive tests may be a valuable biomarker for identifying cognitive impairments in PD.

Randomized phase III trial of gemcitabine-based chemotherapy with in situ RRM1 and ERCC1 protein levels for response prediction in non-small-cell lung cancer

PURPOSE

We evaluated the efficacy of gemcitabine versus gemcitabine and carboplatin in patients with advanced non-small-cell lung cancer (NSCLC) and a performance status (PS) of 2 and assessed if tumoral RRM1 and ERCC1 protein levels are predictive of response to therapy.

PATIENTS AND METHODS

A randomized phase III trial was conducted in community-based oncology practices. Tumor specimens were collected a priori and shipped to a single laboratory for blinded determination of in situ RRM1 and ERCC1 protein expression levels by an automated quantitative immunofluorescent-based technology.

RESULTS

One hundred seventy patients were randomly assigned. Overall median survival was 5.1 months for gemcitabine and 6.7 months for gemcitabine and carboplatin (P = .24). RRM1 (range, 5.3 to 105.6; median, 34.1) and ERCC1 (range, 5.2 to 131.3; median, 34.7) values were significantly and inversely correlated with disease response (r = -0.41; P = .001 for RRM1; r = -0.39; P = .003 for ERCC1; ie, response was better for patients with low levels of expression). A model for response prediction that included RRM1, ERCC1, and treatment arm, was highly predictive of the treatment response observed (P = .0005). We did not find statistically significant associations between survival and RRM1 or ERCC1 levels.

CONCLUSION

Single-agent chemotherapy remains the standard of care for patients with advanced NSCLC and poor PS. Quantitative analysis of RRM1 and ERCC1 protein expression in routinely collected tumor specimens in community oncology practices is predictive of response to gemcitabine and gemcitabine and carboplatin therapy. Oncologists should consider including in situ expression analysis for these proteins into their therapeutic decisions.