Metastatic Lymph Node 64 (MLN64) Expression in Gastric Cancer: The Clinical and Molecular Implications in Drug Resistance

BACKGROUND/AIM

Metastatic lymph node 64 (MLN64) is often co-amplified with ERBB2 (HER2) and plays a role in the progression of breast and prostate cancer. The present study explored the expression of MLN64 in clinical gastric cancer in association with the ERBB family and its impact on drug resistance in patients.

MATERIALS AND METHODS

Two independent gastric cancer cohorts (n=324; n=87) were used to explore the expression profile of MLN64 in conjunction with ERBB family members in clinical gastric cancer and its association with neoadjuvant chemotherapy responses. Gastric cancer AGS and HCG27 cells with MLN64 knockdown were generated to determine the function of MLN64 in cell behavioural changes.

RESULTS

Gastric tumor tissues expressed significantly higher levels of MLN64 compared with normal tissues (p<0.01); however, MLN64 alone was a weak prognostic indicator. An integrated co-expression of MLN64, ERBB4, and NRG4 was a significant factor in assessing overall survival in both cohorts. MLN64 was a profound indicator of patient response to neoadjuvant chemotherapy. In vitro studies indicated a significant contribution of MLN64 to the response of gastric cancer cells to chemodrugs and Her-2 inhibitors. MLN64 knockdown also contributed to the adhesion and migration and suggested a possible mechanism mediated by the interaction between MLN64 and ERBBs.

CONCLUSION

MLN64 is an indicator of patient response to neoadjuvant chemotherapy in gastric cancer. Together with the expression pattern of ERBB4, MLN64 is a poor prognostic factor for patients with gastric cancer.

Recent Developments in NSG and NRG Humanized Mouse Models for Their Use in Viral and Immune Research

Humanized mouse models have been widely used in virology, immunology, and oncology in the last decade. With advances in the generation of knockout mouse strains, it is now possible to generate animals in which human immune cells or human tissue can be engrafted. These models have been used for the study of human infectious diseases, cancers, and autoimmune diseases. In recent years, there has been an increase in the use of humanized mice to model human-specific viral infections. A human immune system in these models is crucial to understand the pathogenesis observed in human patients, which allows for better treatment design and vaccine development. Recent advances in our knowledge about viral pathogenicity and immune response using NSG and NRG mice are reviewed in this paper.

Developmental Disruption of Erbb4 in Pet1+ Neurons Impairs Serotonergic Sub-System Connectivity and Memory Formation

The serotonergic system of mammals innervates virtually all the central nervous system and regulates a broad spectrum of behavioral and physiological functions. In mammals, serotonergic neurons located in the rostral raphe nuclei encompass diverse sub-systems characterized by specific circuitry and functional features. Substantial evidence suggest that functional diversity of serotonergic circuits has a molecular and connectivity basis. However, the landscape of intrinsic developmental mechanisms guiding the formation of serotonergic sub-systems is unclear. Here, we employed developmental disruption of gene expression specific to serotonergic subsets to probe the contribution of the tyrosine kinase receptor ErbB4 to serotonergic circuit formation and function. Through an in vivo loss-of-function approach, we found that ErbB4 expression occurring in a subset of serotonergic neurons, is necessary for axonal arborization of defined long-range projections to the forebrain but is dispensable for the innervation of other targets of the serotonergic system. We also found that Erbb4-deletion does not change the global excitability or the number of neurons with serotonin content in the dorsal raphe nuclei. In addition, ErbB4-deficiency in serotonergic neurons leads to specific behavioral deficits in memory processing that involve aversive or social components. Altogether, our work unveils a developmental mechanism intrinsically acting through ErbB4 in subsets of serotonergic neurons to orchestrate a precise long-range circuit and ultimately involved in the formation of emotional and social memories.

Patient-reported outcome changes at the end of life in recurrent platinum-resistant ovarian cancer: An NRG oncology/GOG study

OBJECTIVES

In a prospective study of platinum-resistant ovarian cancer patients, we examined whether the Disease-related Symptoms-Physical (DRS--P) scale of the NCCN/FACT-Ovarian Cancer Symptom Index-18 (NFOSI-18) is responsive to clinical change in patients estimated by their provider to survive at least six months.

METHODS

The NFOSI-18, and other FACT measures, was collected at study entry and 3 and 6 months post-enrollment. Measures were compared for those who died or dropped off study prior to 3 months or prior to 6 months (assumed as health deterioration over time), or those who stayed on study through 6 months (presumed as stable disease over time). Statistical analyses included a fitted linear mixed model for estimating the group differences over time, Cox regression to assess the probability of survival with patient-reported outcomes, and effect size.

RESULTS

DRS-P scores of patients who completed only one assessment were significantly lower compared to patients who were able to complete two assessments [5.9 points lower (2.0-9.8); p < 0.01], or three assessments [8.1 points lower (4.8-11.5); p < 0.01]. Measures of abdominal discomfort, functional well-being, emotional well-being, and quality of life were also significant, but treatment side effects were not. Further, in every scale except for neurotoxicity, higher (better) baseline scores were associated with a decreased likelihood of death, after adjusting for age, performance and disease status.

CONCLUSION

The NFOSI-18 DRS-P scale is responsive to clinical change. It has potential as an indicator of changing health status with ovarian cancer disease progression, distinct from treatment side effects.

The transseptal puncture experience: Safety insights from FDA MAUDE database

BACKGROUND

There is a paucity of literature on safety and efficacy of various transseptal puncture (TSP) needles.

OBJECTIVES

To assess the reported mechanisms of failure, complications, and outcomes among the most frequently used transseptal needles in the United States.

METHODS

We queried the Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) database between January 2011 and January 2021 for reports on the most commonly used transseptal needles: NRG (Baylis Medical, Montreal, Canada), and BRK (St. Jude, Saint Paul, MN)]. The primary outcome was the mechanism of failure. Secondary outcomes included clinical consequences of device failure.

RESULTS

The final analysis included 306 reports of failure/complication with TSP needles (NRG n = 70, BRK n = 236). The most commonly reported mode of failure was detachment of the needle component (i.e., clip, hub, stopcock, shaft, spring, or needle tip) (14.7% overall; 17.8% BRK; and 4.3% NRG). Among these reports, cardiac perforation was the most common complication (69.9% overall; 69.1% for BRK; and 72.9% for NRG). Pericardiocentesis was the second most commonly reported complication (45.1% overall; 48.3% for BRK; and 34.3% for NRG). The procedure was successfully completed in 33.3% of all cases (36.4% for BRK and 22.9% for NRG), while surgical conversion was needed in (13.4% overall; 14% for BRK and 11.4% for NRG) of the reports. Death occurred in 3.9% of all cases overall (3.4% for BRK and 5.7% for NRG).

CONCLUSIONS

Needle detachment was the most common mode of failure, and cardiac perforation was the most common complication reported with TSP needles. Future efforts should focus on innovative TSP needle design, best practice guidelines, including role of imaging guidance, and increased TSP training.

Human blood serum can donor-specifically antagonize effects of EGFR-targeted drugs on squamous carcinoma cell growth

Many patients fail to respond to EGFR-targeted therapeutics, and personalized diagnostics is needed to identify putative responders. We investigated 1630 colorectal and lung squamous carcinomas and 1357 normal lung and colon samples and observed huge variation in EGFR pathway activation in both cancerous and healthy tissues, irrespectively on EGFR gene mutation status. We investigated whether human blood serum can affect squamous carcinoma cell growth and EGFR drug response. We demonstrate that human serum antagonizes the effects of EGFR-targeted drugs erlotinib and cetuximab on A431 squamous carcinoma cells by increasing IC50 by about 2- and 20-fold, respectively. The effects on clonogenicity varied significantly across the individual serum samples in every experiment, with up to 100% differences. EGF concentration could explain many effects of blood serum samples, and EGFR ligands-depleted serum showed lesser effect on drug sensitivity.

An international randomized phase III trial of pulse actinomycin-D versus multi-day methotrexate for the treatment of low risk gestational trophoblastic neoplasia; NRG/GOG 275

OBJECTIVES

Methotrexate and actinomycin-D are both effective first-line drugs for low-risk (WHO score 0-6) Gestational Trophoblastic Neoplasia (GTN) with considerable debate about which is more effective, less toxic, and better tolerated. The primary trial objective was to test if treatment with multi-day methotrexate (MTX) was inferior to pulse actinomycin-D (ACT-D). Secondary objectives included evaluation of severity and frequency of adverse events, and impact on quality of life (QOL).

METHODS

This was a prospective international cooperative group randomized phase III two arm non-inferiority study (Clinical Trials Identifier: (NCT01535053). The control arm was ACT-D; the experimental arm was multi-day MTX regimen (institutional preference of 5 or 8 day). Outcome measures included complete response rate, recurrence rate, toxicity, and QOL as measured by FACT-G and FACIT supplemental items.

RESULTS

The complete response rates for multi-day methotrexate and pulse actinomycin-D were 88% (23/26 patients) and 79% (22/28 patients) (p = NS) respectively, there were two recurrences in each arm, and 100% of patients survived. Significant toxicity was minimal, but mouth sores (mucositis), and eye pain were significantly more common in the MTX arm (p = 0.001 and 0.01 respectively). Quality of life showed no significant difference in overall quality of life, body image, sexual function, or treatment related side effects. The study was closed for low accrual rate (target 384, actual accrual 57), precluding statistical analysis of the primary objective.

CONCLUSIONS

The complete response rate for multi-day methotrexate was higher than actinomycin-D, but did not reach statistical significance. The multi-day MTX regimens were associated with significantly more mucositis and were significantly less convenient.

Targeting non-small cell lung cancer: driver mutation beyond epidermal growth factor mutation and anaplastic lymphoma kinase fusion

The identification of driver mutations in epidermal growth factor receptor, anaplastic lymphoma kinase, the BRAF and ROS1 genes and subsequent successful clinical development of kinase inhibitors not only significantly improves clinical outcomes but also facilitates the discovery of other novel driver mutations in non-small cell lung cancer. These driver mutations can be categorized into mutations in or near the kinase domain, gene amplification or fusion. In this review, BRAF V600E, EGFR and HER-2 exon 20 mutation, FGFR1-4, K-RAS, MET, neuregulin-1, NRTK, PI3K/AKT/mTOR, RET and ROS1 gene aberration and their therapeutics will be discussed.

Measurements of adiposity as prognostic biomarkers for survival with anti-angiogenic treatment in epithelial ovarian cancer: An NRG Oncology/Gynecologic Oncology Group ancillary data analysis of GOG 218

OBJECTIVE

Adiposity has been hypothesized to interfere with the activity of bevacizumab (BEV), an anti-angiogenic agent. Measurements of adiposity, BMI, surface fat area (SFA), and visceral fat area (VFA) were investigated as prognostic of oncologic outcomes among patients treated with chemotherapy, with or without BEV, on GOG 218, a prospective phase III trial.

METHOD

Pretreatment computed tomography (CT) for 1538 GOG 218 participants were analyzed. Proportional hazards models assessed association between adiposity and overall survival (OS) adjusted for other prognostic factors. The predictive value of adiposity as a function of BEV treatment was assessed in 1019 patients randomized to either chemotherapy (CT) + placebo (P) → P or CT + BEV → BEV.

RESULTS

After adjusting for prognostic factors, SFA was not associated with the overall hazard of death (p = 0.981). There was a non-significant 0.1% (p = 0.062) increase in hazard of death associated with a unit increase in VFA. When comparing the treatment HRs for patients who did and did not receive BEV, there was no association with SFA (p = 0.890) or VFA (p = 0.106). A non-significant 0.8% increase in the hazard of death with unit increase in BMI (p = 0.086) was observed. BMI values were not predictive of a longer survival for patients with BEV vs placebo (p = 0.606).

CONCLUSION

Measures of adiposity strongly correlated to one another but were not predictive of efficacy for BEV. VFA is a weak prognostic factor.

A new genetic tool to improve immune-compromised mouse models: Derivation and CRISPR/Cas9-mediated targeting of NRG embryonic stem cell lines

Development of human hematopoietic stem cells and differentiation of embryonic stem (ES) cells/induced pluripotent stem (iPS) cells to hematopoietic stem cells are poorly understood. NOD (Non-obese diabetic)-derived mouse strains, such as NSG (NOD-Scid-il2Rg) or NRG (NOD-Rag1-il2Rg), are the best available models for studying the function of fetal and adult human hematopoietic cells as well as ES/iPS cell-derived hematopoietic stem cells. Unfortunately, engraftment of human hematopoietic stem cells is very variable in these models. Introduction of additional permissive mutations into these complex genetic backgrounds of the NRG/NSG mice by natural breeding is a very demanding task in terms of time and resources. Specifically, since the genetic elements defining the NSG/NRG phenotypes have not yet been fully characterized, intense backcrossing is required to ensure transmission of the full phenotype. Here we describe the derivation of embryonic stem cell (ESC) lines from NRG pre-implantation embryos generated by in vitro fertilization followed by the CRISPR/CAS9 targeting of the Gata-2 locus. After injection into morula stage embryos, cells from three tested lines gave rise to chimeric adult mice showing high contribution of the ESCs (70%-100%), assessed by coat color. Moreover, these lines have been successfully targeted using Cas9/CRISPR technology, and the mutant cells have been shown to remain germ line competent. Therefore, these new NRG ESC lines combined with genome editing nucleases bring a powerful genetic tool that facilitates the generation of new NOD-based mouse models with the aim to improve the existing xenograft models.

Correlation between Surgeon's assessment and radiographic evaluation of residual disease in women with advanced stage ovarian cancer reported to have undergone optimal surgical cytoreduction: An NRG Oncology/Gynecologic Oncology Group study

PURPOSE

We sought to determine the level of concordance among surgeons' assessment of residual disease (RD) and pre-treatment computed tomography (CT) findings among women who underwent optimal surgical cytoreduction for advanced stage ovarian cancer.

METHODS

This is a post-trial ad hoc analysis of a phase 3 randomized clinical trial evaluating the impact of bevacizumab in primary and maintenance therapy for patients with advanced stage ovarian cancer following surgical cytoreduction. All subjects underwent imaging of the chest/abdomen/pelvis to establish a post-surgical baseline prior to the initiation of chemotherapy. Information collected on trial was utilized to compare surgeon's operative assessment of RD, to pre-treatment imaging.

RESULTS

Of 1873 enrolled patients, surgical outcome was described as optimal (RD≤1cm) in 639 subjects. Twelve patients were excluded as they did not have a baseline, pretreatment imaging, leaving 627 participants for analysis. The average interval from surgery to baseline scan was 26days (range: 1-109). In 251 cases (40%), the post-operative scan was discordant with surgeon assessment, demonstrating RD>1cm in size. RD>1cm was most commonly identified in the right upper quadrant (28.4%), retroperitoneal para-aortic lymph nodes (RD>1.5cm; 28.2%) and the left upper quadrant (10.7%). Patients with RD>1cm on pre-treatment CT (discordant) exhibited a significantly greater risk of disease progression (HR 1.30; 95% CI 1.08-1.56; p=0.0059).

CONCLUSIONS

Among patients reported to have undergone optimal cytoreduction, 40% were found to have lesions >1cm on postoperative, pretreatment imaging. Although inflammatory changes and/or rapid tumor regrowth could account for the discordance, the impact on PFS and distribution of RD may suggest underestimation by the operating surgeon.

Associations between etiologic factors and mortality after endometrial cancer diagnosis: the NRG Oncology/Gynecologic Oncology Group 210 trial

BACKGROUND

Few studies have analyzed relationships between risk factors for endometrial cancer, especially with regard to aggressive (non-endometrioid) histologic subtypes, and prognosis. We examined these relationships in the prospective NRG Oncology/Gynecologic Oncology Group 210 trial.

METHODS

Prior to surgery, participants completed a questionnaire assessing risk factors for gynecologic cancers. Pathology data were derived from clinical reports and central review. We used the Fine and Gray subdistribution hazards model to estimate subhazard ratios (HRs) and 95% confidence intervals (CIs) for associations between etiologic factors and cause-specific subhazards in the presence of competing risks. These models were stratified by tumor subtype and adjusted for stage and socioeconomic status indicators.

RESULTS

Median follow-up was 60months after enrollment (range: 1day-118months). Among 4609 participants, a total of 854 deaths occurred, of which, 582 deaths were attributed to endometrial carcinoma. Among low-grade endometrioid cases, endometrial carcinoma-specific subhazards were significantly associated with age at diagnosis (HR=1.04, 95% CI=1.01-1.06 per year, P-trend) and BMI (class II obesity vs. normal BMI: HR=2.29, 95% CI=1.06-4.98, P-trend=0.01). Among high-grade endometrioid cases, endometrial carcinoma-specific subhazards were associated with age at diagnosis (HR=1.05, 95% CI=1.02-1.07 per year, P-trend<0.001). Among non-endometrioid cases, endometrial carcinoma-specific subhazards were associated with parity relative to nulliparity among serous (HR=0.55, 95% CI=0.36-0.82) and carcinosarcoma cases (HR=2.01, 95% CI=1.00-4.05).

DISCUSSION

Several endometrial carcinoma risk factors are associated with prognosis, which occurs in a tumor-subtype specific context. If confirmed, these results would suggest that factors beyond histopathologic features and stage are related to prognosis. ClinicalTrials.gov Identifier: NCT00340808.

Long term human reconstitution and immune aging in NOD-Rag (-)-γ chain (-) mice

Aging of the human immune system is characterized by a gradual loss of immune function and a skewing of hematopoiesis toward the myeloid lineage, a reduction in the lymphocytic lineage, and progressive increases in senescent memory T cells at the expense of naïve T cells. Both the innate and the adaptive branches of the immune system are affected, including neutrophils, macrophages, dendritic cells and lymphocytes. Mice, the most common research model, although inexpensive, do not necessarily reflect the human immune system in terms of its interaction with infectious agents of human origin or environmental factors. This study analyzed whether a human immune system contained within the NOD-Rag (-)-γ chain (-) mouse model could realistically be used to evaluate the development and therapy of aging-related diseases. To that end lightly irradiated NOD-Rag (-)-γ chain (-) mice were injected intra-hepatically on day 1 of life with purified cord blood-derived CD34(+) stem and progenitor cells. Multiple mice were constructed from each cord blood donor. Mice were analyzed quarterly for age-related changes in the hematopoietic and immune systems, and followed for periods up to 18-24 months post-transplant. Flow cytometric analyses were performed for hematopoietic and immune reconstitution. It was observed that NOD-Rag (-)-γ chain (-) mice could be "humanized" long-term using cord blood stem cells, and that some evidence of immune aging occurred during the life of the mice.

Origin, lineage and function of cerebellar glia

The glial cells of the cerebellum, and particularly astrocytes and oligodendrocytes, are characterized by a remarkable phenotypic variety, in which highly peculiar morphological features are associated with specific functional features, unique among the glial cells of the entire CNS. Here, we provide a critical report about the present knowledge of the development of cerebellar glia, including lineage relationships between cerebellar neurons, astrocytes and oligodendrocytes, the origins and the genesis of the repertoire of glial types, and the processes underlying their acquisition of mature morphological and functional traits. In parallel, we describe and discuss some fundamental roles played by specific categories of glial cells during cerebellar development. In particular, we propose that Bergmann glia exerts a crucial scaffolding activity that, together with the organizing function of Purkinje cells, is necessary to achieve the normal pattern of foliation and layering of the cerebellar cortex. Moreover, we discuss some of the functional tasks of cerebellar astrocytes and oligodendrocytes that are distinctive of cerebellar glia throughout the CNS. Notably, we report about the regulation of synaptic signalling in the molecular and granular layer mediated by Bergmann glia and parenchymal astrocytes, and the functional interaction between oligodendrocyte precursor cells and neurons. On the whole, this review provides an extensive overview of the available literature and some novel insights about the origin and differentiation of the variety of cerebellar glial cells and their function in the developing and mature cerebellum.

Phosphorylation of P-Rex1 at serine 1169 participates in IGF-1R signaling in breast cancer cells

Former reports demonstrated that P-Rex, a Rac guanine nucleotide exchange factor (GEF), participated in signaling upon activation of the ErbB receptor tyrosine kinases (RTKs). Activation of ErbB receptors turned on a phosphorylation/dephosphorylation cycle of P-Rex in which stimulation of serine(1169) phosphorylation played a critical role in the activation of this GEF. This precedent raised the important question of whether this P-Rex1 activation mechanism was restricted to ErbB receptors or could represent a general signaling event shared by several RTKs. To explore that possibility the effect of activation of distinct RTKs on the phosphorylation of P-Rex1 at serine(1169) was analyzed. Here we report that IGF-1 and FGF receptors activate serine(1169) phosphorylation of P-Rex1. P-Rex1 phosphorylation was required for IGF-1-induced up-regulation of Rac activity and cell proliferation. Moreover, IGF-1-induced adhesion was impaired in MCF7 breast cancer cells by knocking down P-Rex1. These results demonstrate that phosphorylation P-Rex1 at S(1169) represents a mechanism of activation of P-Rex1 common to multiple RTKs. We suggest that P-Rex proteins may act as novel and important transducers of pro-oncogenic signals that emanate from RTKs, and could even participate in other biological responses, such as metabolic control, which are not strictly related to the proliferation effects of RTKs.

Mitochondrial glutamate carriers from Drosophila melanogaster: biochemical, evolutionary and modeling studies

The mitochondrial carriers are members of a family of transport proteins that mediate solute transport across the inner mitochondrial membrane. Two isoforms of the glutamate carriers, GC1 and GC2 (encoded by the SLC25A22 and SLC25A18 genes, respectively), have been identified in humans. Two independent mutations in SLC25A22 are associated with severe epileptic encephalopathy. In the present study we show that two genes (CG18347 and CG12201) phylogenetically related to the human GC encoding genes are present in the D. melanogaster genome. We have functionally characterized the proteins encoded by CG18347 and CG12201, designated as DmGC1p and DmGC2p respectively, by overexpression in Escherichia coli and reconstitution into liposomes. Their transport properties demonstrate that DmGC1p and DmGC2p both catalyze the transport of glutamate across the inner mitochondrial membrane. Computational approaches have been used in order to highlight residues of DmGC1p and DmGC2p involved in substrate binding. Furthermore, gene expression analysis during development and in various adult tissues reveals that CG18347 is ubiquitously expressed in all examined D. melanogaster tissues, while the expression of CG12201 is strongly testis-biased. Finally, we identified mitochondrial glutamate carrier orthologs in 49 eukaryotic species in order to attempt the reconstruction of the evolutionary history of the glutamate carrier function. Comparison of the exon/intron structure and other key features of the analyzed orthologs suggests that eukaryotic glutamate carrier genes descend from an intron-rich ancestral gene already present in the common ancestor of lineages that diverged as early as bilateria and radiata.

Lead roles for supporting actors: critical functions of inner ear supporting cells

Many studies that aim to investigate the underlying mechanisms of hearing loss or balance disorders focus on the hair cells and spiral ganglion neurons of the inner ear. Fewer studies have examined the supporting cells that contact both of these cell types in the cochlea and vestibular end organs. While the roles of supporting cells are still being elucidated, emerging evidence indicates that they serve many functions vital to maintaining healthy populations of hair cells and spiral ganglion neurons. Here we review recent studies that highlight the critical roles supporting cells play in the development, function, survival, death, phagocytosis, and regeneration of other cell types within the inner ear. Many of these roles have also been described for glial cells in other parts of the nervous system, and lessons from these other systems continue to inform our understanding of supporting cell functions. This article is part of a Special Issue entitled "Annual Reviews 2013".