Association between polymorphisms in cancer-related genes and early onset of esophageal adenocarcinoma

Early-Onset Gastrointestinal Malignancies: An Investigation into a Rising Concern

There is growing recognition of early-onset gastrointestinal (GI) malignancies in young adults < 50 years of age. While much of the literature has emphasized colorectal cancer, these also include esophageal, gastric, liver, pancreatic, and biliary tract malignancies. Various factors, including lifestyle, hereditary, and environmental elements, have been proposed to explain the rising incidence of GI malignancies in the younger population. This review aims to provide an overview of the recent literature, including global trends and information regarding genetic and environmental risk factors.

Clinical and molecular characteristics of early-onset vs average-onset esophagogastric cancer

BACKGROUND

The rate of esophagogastric cancer is rising among individuals under 50 years of age. It remains unknown whether early-onset esophagogastric cancer represents a unique entity. This study investigated the clinical and molecular characteristics of early-onset and average-onset esophagogastric cancer .

METHODS

We reviewed the Memorial Sloan Kettering Cancer Center gastric, esophageal, and gastroesophageal junction cancer database. Associations between baseline characteristics and tumor and germline molecular alterations were compared between those with early-onset and average-onset esophagogastric cancer using Fisher exact tests and the Benjamini-Hochberg method for multiple-hypothesis correction.

RESULTS

We included 1123 patients with early-onset esophagogastric cancer (n = 219; median age = 43 years [range = 18-49 years]) and average-onset esophagogastric cancer (n = 904; median age = 67 years [range = 50-94 years]) treated between 2005 and 2018. The early-onset group had more women (39% vs 28%, P = .002). Patients with early-onset esophagogastric cancer were more likely to have a gastric primary site (64% vs 44%, P < .0001). The signet ring cell and/or diffuse type was 3 times more common in the early-onset esophagogastric cancer group (31% vs 9%, P < .0001). Early-onsite tumors were more frequently genomically stable (31% vs 18%, P = .0002) and unlikely to be microsatellite instability high (2% vs 7%, P = .003). After restricting to adenocarcinoma and signet ring cell and/or diffuse type carcinomas, we observed no difference in stage (P = .40) or overall survival from stage IV diagnosis (median = 22.7 vs 22.1 months, P = .78).

CONCLUSIONS

Our study supported a preponderance of gastric primary disease sites, signet ring histology, and genomically stable molecular subtypes in early-onset esophagogastric cancer. Our findings highlight the need for further research to define the underlying pathogenesis and strategies for early detection and prevention.

The microbiome and rise of early-onset cancers: knowledge gaps and research opportunities

Accumulating evidence indicates an alarming increase in the incidence of early-onset cancers, which are diagnosed among adults under 50 years of age, in the colorectum, esophagus, extrahepatic bile duct, gallbladder, liver, stomach, pancreas, as well as the bone marrow (multiple myeloma), breast, head and neck, kidney, prostate, thyroid, and uterine corpus (endometrium). While the early-onset cancer studies have encompassed research on the wide variety of organs, this article focuses on research on digestive system cancers. While a minority of early-onset cancers in the digestive system are associated with cancer-predisposing high penetrance germline genetic variants, the majority of those cancers are sporadic and multifactorial. Although potential etiological roles of diets, lifestyle, environment, and the microbiome from early life to adulthood (i.e. in one's life course) have been hypothesized, exact contribution of each of these factors remains uncertain. Diets, lifestyle patterns, and environmental exposures have been shown to alter the oral and intestinal microbiome. To address the rising trend of early-onset cancers, transdisciplinary research approaches including lifecourse epidemiology and molecular pathological epidemiology frameworks, nutritional and environmental sciences, multi-omics technologies, etc. are needed. We review current evidence and discuss emerging research opportunities, which can improve our understanding of their etiologies and help us design better strategies for prevention and treatment to reduce the cancer burden in populations.

Biological and clinical implications of early-onset cancers: A unique subtype

In recent years, the incidence of cancers is continuously increasing in young adults. Early-onset cancer (EOC) is usually defined as patients with cancers under the age of 50, and may represent a unique subgroup due to its special disease features. Overall, EOCs often initiate at a young age, present as a better physical performance but high degree of malignancy. EOCs also share common epidemiological and hereditary risk factors. In this review, we discuss several representative EOCs which were well studied previously. By revealing their clinical and molecular similarities and differences, we consider the group of EOCs as a unique subtype compared to ordinary cancers. In consideration of EOC as a rising threat to human health, more researches on molecular mechanisms, and large-scale, prospective clinical trials should be carried out to further translate into improved outcomes.

Proportion of Early-Onset Gastric and Esophagus Cancers Has Changed Over Time With Disproportionate Impact on Black and Hispanic Patients

PURPOSE

The proportion of gastroesophageal junction adenocarcinoma is increasing. This study evaluated trends in early-onset gastric and esophageal cancers and compared socioeconomic and clinical characteristics between early-onset versus late-onset disease.

MATERIALS AND METHODS

We included all patients with gastric and esophageal cancer from 2004 to 2015 from the National Cancer Database. Patients were categorized by age < 50, 50-69, and ≥ 70 years. Differences in pathologic and socioeconomic factors between early-onset and late-onset cancers were assessed by using chi-square test. The effects of demographic and socioeconomic factors on overall survival (OS) were assessed using Cox models.

RESULTS

The proportion of patients with early-onset gastric cancer increased from 23.9% in 2004-2006 to 26.2% in 2013-2015, whereas the proportion of early-onset esophageal cancer decreased from 27.3% in 2004-2006 to 23.1% in 2013-2015. For both malignancies, the early-onset group was more likely to be Black or Hispanic and more likely to be diagnosed with stage IV cancer. Black patients had the worst median OS in both malignancies. In gastric cancer, within the Black patient group, patients experienced worse OS if they had government insurance versus private insurance (hazard ratio 1.2; 95% CI, 1.1 to 1.3; P value < .0001) or if they were in the lowest community median income category versus the highest category (hazard ratio 1.2; 95% CI, 1.1 to 1.3; P value < .0001).

CONCLUSION

Early-onset gastric cancer is increasing, whereas early-onset esophageal cancer is declining. Early-onset gastric cancer disproportionately affects non-White patients, particularly Hispanic patients. Black patients have worse outcomes compared with other races for both gastric and esophageal cancer.

Prognostic signature of esophageal adenocarcinoma based on pyroptosis-related genes

Background

The role of pyroptosis-related genes (PRGs) in esophageal adenocarcinoma (EAC) remains unknown.

Methods

In this study, the first PRGs prognostic signature (PPS) of EAC was constructed based on the results of multivariate stepwise Cox regression analysis. Based on 1,047 samples of EAC and normal esophagus (NE), differentially expressed PRGs were selected for the establishment of the PPS. The discrimination effect of this PPS was detected by receiver operating characteristic curves, and the prognosis value of this PPS was determined through Cox regression analysis and Kaplan-Meier curves. Net benefits of the EAC patients from the nomogram (constructed based on the PPS and some clinical parameters) were assessed via decision curve analysis. The potential molecular mechanism of the PPS in EAC was explored via gene set enrichment analysis. The ability of PPS to distinguish EAC and NE was evaluated based on the results of summary receiver operating characteristic curves.

Results

The significant prognostic value of PPS can be observed at all of the training cohort, test cohort, and validation cohort, such as its independent risk role in the prognosis of the EAC patients (hazard ratio > 0; 95% CI not including 0). The positive net benefits of the nomogram for the EAC patients can be detected via decision curve analysis, and the potential molecular mechanism of the PPS in EAC is likely related to cell pyroptosis. Last, some of the PRGs (particularly CASP5) included in this PPS specifically support its feasibility for identifying EAC (area under the curves > 0.7).

Conclusions

The construction of this PPS in EAC enhances the present understanding of the relationship between PRGs and EAC, thus representing a novel approach to the clinical identification and management of EAC based on PRGs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01196-x.

Genetic interactions between ANLN and KDR are prognostic for breast cancer survival

Single nucleotide polymorphisms (SNPs) are the most common genetic variation in mammalian cells with prognostic potential. Anillin-actin binding protein (ANLN) has been identified as being involved in PI3K/PTEN signaling, which is critical in cell life/death control, and kinase insert domain receptor (KDR) encodes a key receptor mediating the cancer angiogenesis/metastasis switch. Knowledge of the intrinsic connections between PI3K/PTEN and KDR signaling, which represent two critical transitions in carcinogenesis, led the present study to investigate the effects of the potential synergy between ANLN and KDR on breast cancer outcome and identify relevant SNPs driving such a synergy at the genetic level. The survival associations of SNPs from KDR and ANLN were assessed through pairwise interaction survival analysis, quantitative trait loci analysis, pathway enrichment analysis and network construction, and the interactions between ANLN and KDR were validated in vitro. It was found that both rare homozygotes in the ANLN:rs12535394 and KDR:rs11133360 SNP pair are prognostic of favorable breast cancer survival and underpin the prominent roles of the immune response in cancer state control. This study contributes to breast cancer prognosis and therapeutic design by providing genetic evidence of interactions between ANLN and KDR, and suggesting the prominent role of the immune response in driving the synergies between the cancer cell life/death and angiogenesis/metastasis transitions during carcinogenesis.

Etiology, cancer stem cells and potential diagnostic biomarkers for esophageal cancer

Esophageal cancer (EC) has been a leading cause of cancer death worldwide in part due to late detection and lack of precision treatment. EC includes two major malignancies, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Recent studies reveal that ESCC and EAC have distinct cell of origin and contain cancer stem cells (also known as tumor initiating cells) expressing different cell surface markers. These biomarkers have potentially important values for both early detection and finding effective therapy. In this review we summarize the updated findings for cell of origin and provide an overview of cancer cell biomarkers that have been tested for ESCC and EAC. In addition, we also discuss recent progress in the study of molecular mechanisms leading to these malignancies.

Identifying potential metastasis-related long non-coding RNAs, microRNAs, and message RNAs in the esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the predominant form with the highest incidence. We aimed to find metastasis-related differentially expressed long noncoding RNAs (lncRNAs), microRNAs (miRNAs), and messenger RNA (mRNAs) in ESCC. We first obtained the lncRNAs, miRNAs, and mRNAs profiles. The differentially expressed lncRNAs, miRNAs, and mRNAs were obtained, followed by the functional annotation. Then the interaction networks of miRNA-mRNA, lncRNA-mRNA coexpression, lncRNA-miRNA, and lncRNA-miRNA-mRNA were constructed. In addition, systematic expression pattern analysis of differentially expressed lncRNAs, miRNA, and mRNA in the normal, metastasis, and nonmetastasis was performed. Survivability of differentially expressed lncRNAs, miRNAs, and mRNA was analyzed. A total of 613 differentially expressed lncRNAs, 35 differentially expressed miRNAs, and 1586 differentially expressed mRNAs were obtained. Several interactions of H19-hsa-mir-222-chromobox 2 (CBX2), H19-hsa-mir-330-phosphoinositide-3-kinase regulatory subunit 4 (PIK3R4), KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1)/CTB-89H12.4-hsa-mir-374a-vascular endothelial growth factor A (VEGFA), MALAT1/X inactive specific transcript (XIST)/XIST antisense RNA (TSIX)-hsa-mir-340-tumor necrosis factor receptor superfamily member 10A (NFRSF10A) were identified to play key roles in the metastasis of ESCC. In addition, KCNQ1OT1, TSIX, and XIST were significantly associated with the survival time of patients. In conclusion, our study may be helpful in understanding the pathological mechanism and providing new diagnostic and therapeutic biomarkers for ESCC.

GOG 8020/210: Risk stratification of lymph node metastasis, disease progression and survival using single nucleotide polymorphisms in endometrial cancer: An NRG oncology/gynecologic oncology group study

OBJECTIVES

The ability to stratify a patient's risk of metastasis and survival permits more refined care. A proof of principle study was undertaken to investigate the relationship between single nucleotide polymorphisms (SNPs) in literature based candidate cancer genes and the risk of nodal metastasis and clinical outcome in endometrioid endometrial cancer (EEC) patients.

METHODS

Surgically-staged EEC patients from the Gynecologic Oncology Group or Washington University School of Medicine with germline DNA available were eligible. Fifty-four genes represented by 384 SNPs, were evaluated by Illumina Custom GoldenGate array. Association with lymph node metastases was the primary outcome. Progression-free survival (PFS) and overall survival (OS) was also evaluated.

RESULTS

361 SNPs with high quality genotype data were evaluated in 337 patients with outcome data. Five SNPs in CXCR2 had an odds ratio (OR) between 0.68 and 0.70 (p-value ≤ 0.025). The A allele rs946486 in ABL had an OR of 1.5 (p-value = 0.01) for metastasis. The G allele in rs7795743 in EGFR had an OR for metastasis of 0.68 (p-value = 0.02) and hazard ratio (HR) for progression of 0.66 (p-value = 0.004). Importantly, no SNP met genome wide significance after adjusting for multiple test correcting and clinical covariates. The A allele in rs2159359 SNP in NME1 and the G allele in rs13222385 in EGFR were associated with worse OS. Both exhibited genome wide significance; rs13222385 remained significant after adjusting for prognostic clinical variables.

CONCLUSION

SNPs in cancer genes including rs2159359 SNP in NME1 and rs13222385 in EGFR may stratify risk in EEC and are prioritized for further investigation.

MMP-14 single-nucleotide polymorphisms are related to steroid-induced osteonecrosis of the femoral head in the population of northern China

Background

Osteonecrosis of the femoral head (ONFH) is a refractory disease which frequently occurs in young and middle‐aged people. Recent studies indicated that MMP‐14 played an important role in the development of chondrocytes, metabolism of osteoblasts as well as fate decision of hypertrophic chondrocytes. The aim of this study was to investigate the association between polymorphisms of MMP‐14 and steroid‐induced osteonecrosis of the femoral head in the Chinese population.

Methods

We selected 7 SNPs (rs3751488, rs1003349, rs1042703, rs2236302, rs1042704, rs2236303, and rs2236304) on gene MMP‐14. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using the chi‐squared test, genetic model analysis, haplotype analysis, and stratification analysis.

Results

We discovered that the genotype “G/G” of rs2236302 was associated with ONFH risk in the MMP‐14 in the codominant model (OR = 8.62, 95% CI = 1.07–69.46, p = 0.038) and recessive model (OR = 8.86, 95% CI = 1.10–71.31, p = 0.013).

Conclusions

We have confirmed that the susceptive SNPs (rs2236302) of MMP‐14 from the MMPs/TIMPs system exhibit a significant association with increased risk of steroid‐induced ONFH in the population of northern China.

Efficacy of narrow-band imaging in detecting early esophageal cancer and risk factors for its occurrence

OBJECTIVE

The aim of this study is to evaluate the efficacy of narrow-band imaging (NBI) in the detecting early esophageal cancer and precancerous lesions and to investigate the risk factors for its occurrence.

METHODS

The esophagus was examined with ordinary endoscopy, NBI, and iodine staining. All the lesions were confirmed by histopathologically as the gold standard; NBI and intrapapillary capillary scale (IPCL) scale were compared with pathologic diagnosis. The accuracy, sensitivity, specificity, positive and negative predictive values (PPV, NPV) were calculated. Subgroup analysis was performed between the elderly vs. younger group, and head and neck squamous cell cancer (HNSCC) vs. non-HNSCC patients.

RESULTS

Ninety lesions were detected with ordinary endoscopy, 108 with NBI, and 120 with iodine staining. All esophageal cancers were detected both by NBI and by iodine staining. Accuracy, sensitivity, and specificity for esophageal cancer and precancerous lesion were 67.8%, 58.1%, and 76.6%; 92%, 89.7%, and 96%; 93.4%, 93.4%, and 93.2%, respectively. NBI endoscopy and iodine staining were superior to ordinary endoscopy for detecting esophageal cancer and precancerous lesions (p < 0.05). NBI showed better detection of esophageal neoplasms in the elderly patients (p < 0.001). The incidence of multiple squamous cell cancers (SCCs) was significantly higher in non-elderly group (p = 0.009). NBI can also detect more esophageal neoplastic lesions in patients with head and neck cancers (p = 0.003).

CONCLUSIONS

NBI endoscopy appears as effective as Lugol staining to detect and screen the early esophageal cancer. NBI shows better detection of esophageal neoplasms in the elderly patients. The incidence of multiple SCCs was much higher in non-elderly patients.

The Epidemiology of Esophageal Adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has increased in many Western countries and is higher in men than women. Some risk factors for EAC have been identified-mainly gastroesophageal reflux disease, Barrett's esophagus, obesity, and tobacco smoking. It is not clear whether interventions to address these factors can reduce risk of EAC, although some evidence exists for smoking cessation. Although consumption of alcohol is not associated with EAC risk, other exposures, such as physical activity, nutrition, and medication use, require further study. Genetic variants have been associated with risk for EAC, but their overall contribution is low. Studies are needed to investigate associations between risk factors and the molecular subtypes of EAC. The prognosis for patients with EAC has slightly improved, but remains poor-screening and surveillance trials of high-risk individuals are needed.

Leu72Met and Other Intronic Polymorphisms in the GHRL and GHSR Genes Are Not Associated with Type 2 Diabetes Mellitus, Insulin Resistance, or Serum Ghrelin Levels in a Saudi Population

BACKGROUND

Ghrelin (GHRL), a gastric peptide encoded by the GHRL gene, is known to be involved in energy homeostasis via its G protein receptor, encoded by the growth hormone secretagogue receptor (GHSR) gene. Some studies have shown associations between plasma GHRL levels and GHRL single-nucleotide polymorphisms (SNPs), namely the Leu72Met polymorphism (rs696217 TG), with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), while others have not. The controversies in these associations raise the issue of 'which SNPs in which populations.' The aim of this study was to investigate whether SNPs in GHRL and/or GHSR genes were associated with T2DM, IR, or plasma GHRL levels among Arab Saudis.

METHODS

Blood was collected from 208 Saudi subjects with (n=107) and without (n=101) T2DM. DNA samples from these subjects were analyzed by real-time polymerase chain reaction to genotype five intronic SNPs in the GHRL (rs696217 TG, rs27647 CT, rs2075356 CT, and rs4684677 AT) and GHSR (rs509030 GC) genes. In addition, plasma GHRL levels were measured by a radioimmunoassay.

RESULTS

None of the SNPs were associated with T2DM, IR, or plasma GHRL levels. The frequencies of the alleles, genotypes, and haplotypes of the five SNPs were comparable between the T2DM patients and the non-diabetic subjects. A large number of the GHRL haplotypes indicates the molecular heterogeneity of the preproghrelin gene in this region.

CONCLUSION

Neither the Leu72Met polymorphism nor the other intronic GHRL and GHSR SNPs were associated with T2DM, IR, or GHRL levels. Further investigations should be carried out to explain the molecular basis of the association of the GHRL peptide with T2DM and IR.

Basal progenitor cells bridge the development, malignant cancers, and multiple diseases of esophagus

The esophagus is a pivotal organ originating from anterior foregut that links the mouth and stomach. Moreover, its development involves precise regulation of multiple signal molecules and signal transduction pathways. After abnormal regulation of these molecules in the basal cells of the esophagus occurs, multiple diseases, including esophageal atresia with or without tracheoesophageal fistula, Barrett esophagus, gastroesophageal reflux, and eosinophilic esophagitis, will take place as a result. Furthermore, expression changes of signal molecules or signal pathways in basal cells and the microenvironment around basal cells both can initiate the switch of malignant transformation. In this review, we highlight the molecular events underlying the transition of normal development to multiple esophageal diseases. Additionally, the animal models of esophageal development and related diseases, challenges, and strategies are extensively discussed.

Age-specific risk factor profiles of adenocarcinomas of the esophagus: A pooled analysis from the international BEACON consortium

Esophageal (EA) and esophagogastric junction (EGJA) adenocarcinoma have been steadily increasing in frequency in younger people; however, the etiology of these cancers is poorly understood. We therefore investigated associations of body mass index (BMI), cigarette smoking, alcohol consumption, gastroesophageal reflux and use of nonsteroidal anti-inflammatory drugs (NSAIDs) in relation to age-specific risks of EA and EGJA. We pooled individual participant data from eight population-based, case-control studies within the international Barrett's and Esophageal Adenocarcinoma Consortium (BEACON). The analysis included 1,363 EA patients, 1,472 EGJA patients and 5,728 control participants. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for age-specific (<50, 50-59, 60-69, ≥70 years) cancer outcomes, as well as interactions by age. BMI, smoking status and pack-years, recurrent gastroesophageal reflux and frequency of gastroesophageal reflux were positively associated with EA and EGJA in each age group. Early-onset EA (<50 years) had stronger associations with recurrent gastroesophageal reflux (OR = 8.06, 95% CI: 4.52, 14.37; peffect modification  = 0.01) and BMI (ORBMI ≥ 30 vs . <25  = 4.19, 95% CI: 2.23, 7.87; peffect modification  = 0.04), relative to older age groups. In contrast, inverse associations of NSAID use were strongest in the oldest age group (≥70 years), although this apparent difference was not statistically significant. Age-specific associations with EGJA showed similar, but slightly weaker patterns and no statistically significant differences by age were observed. Our study provides evidence that associations between obesity and gastroesophageal reflux are stronger among earlier onset EA cancers.

Cancer subclonal genetic architecture as a key to personalized medicine

The future of personalized oncological therapy will likely rely on evidence-based medicine to integrate all of the available evidence to delineate the most efficacious treatment option for the patient. To undertake evidence-based medicine through use of targeted therapy regimens, identification of the specific underlying causative mutation(s) driving growth and progression of a patient's tumor is imperative. Although molecular subtyping is important for planning and treatment, intraclonal genetic diversity has been recently highlighted as having significant implications for biopsy-based prognosis. Overall, delineation of the clonal architecture of a patient's cancer and how this will impact on the selection of the most efficacious therapy remain a topic of intense interest.

Clinicopathological characteristics of esophageal squamous cell carcinoma in patients younger than 50 years

PURPOSE

This study clarifies age differences in clinicopathologic characteristics and risk factor exposure of patients who have undergone esophagectomy for esophageal cancer (EC).

METHODS

Clinical results of esophagectomy were compared between 22 patients younger than 50 years of age (Group I) and 327 patients older than 50 years of age (Group II) with esophageal squamous cell carcinoma.

RESULTS

The two groups did not significantly differ in clinicopathological characteristics, including prognosis. Postoperative pulmonary complication incidence rates were 4.2 % (Group I) and 14.4 % (Group II). In Group I, the incidence of multiple ECs was 36.4 %, and association with head and neck cancer was 31.8 %, which were significantly higher than in Group II (13.4 %, p = 0.021; and 9.2 %, p = 0.015, respectively). Furthermore, the patients in Group I with multiple cancers were almost all heavy smokers and/or users of alcohol.

CONCLUSIONS

These results suggest that multiple upper aerodigestive tract cancers are associated with heavy exposure to risk factors in patients younger than 50 years of age.

B-cell Lymphoma 2 rs17757541 C>G polymorphism was associated with an increased risk of gastric cardiac adenocarcinoma in a Chinese population

AIM

Apoptosis has been considered as a fundamental component in cancer pathogenesis, and related genetic factors might play an important role in gastric cardiac adenocarcinoma (GCA) genesis.

METHODS

We conducted a hospital based case-control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs): BCL2 rs17757541 C>G, BCL2 rs12454712 T>C, FAS rs2234767 G>A, FASL/FASLG rs763110 C>T, ERBB2 rs1136201 A>G and VEGFR2/KDR rs11941492 C>T on the development of GCA. A total of 243 GCA cases and 476 controls were recruited for the study and genotypes were determined using a custom-by-design 48-Plex SNPscanTM Kit.

RESULTS

The BCL2 rs17757541 C>G polymorphism was associated with increased risk of GCA. However, there was no significant associations with the other five SNPs. Stratified analyses indicated a significantly increased risk of GCA associated with the BCL2 rs17757541 C>G polymorphism among males, older patients and those with a history of smoking or drinking.

CONCLUSION

These findings indicated that the functional polymorphism BCL2 rs17757541 C>G might contribute to GCA susceptibility. However, our results were limited by small sample size. Future larger studies are required to confirm our current findings.

Overcoming intratumor heterogeneity of polygenic cancer drug resistance with improved biomarker integration

Improvements in technology and resources are helping to advance our understanding of cancer-initiating events as well as factors involved with tumor progression, adaptation, and evasion of therapy. Tumors are well known to contain diverse cell populations and intratumor heterogeneity affords neoplasms with a diverse set of biologic characteristics that can be used to evolve and adapt. Intratumor heterogeneity has emerged as a major hindrance to improving cancer patient care. Polygenic cancer drug resistance necessitates reconsidering drug designs to include polypharmacology in pursuit of novel combinatorial agents having multitarget activity to overcome the diverse and compensatory signaling pathways in which cancer cells use to survive and evade therapy. Advances will require integration of different biomarkers such as genomics and imaging to provide for more adequate elucidation of the spatially varying location, type, and extent of diverse intratumor signaling molecules to provide for a rationale-based personalized cancer medicine strategy.

Association analysis of nitric oxide synthases: NOS1, NOS2A and NOS3 genes, with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disorder of the central nervous system.

AIM

To explore the genetic basis of three nitric oxide synthase (NOS) genes: NOS1, NOS2A and NOS3, with susceptibility to MS.

SUBJECTS AND METHODS

A total of 122 MS patients and 118 healthy controls screened for NOS1 (rs2682826, rs41279104), NOS2A (CCTTT)n/(TAAA)n and NOS3 (rs1800783, rs1800779, rs2070744, 27bpVNTR) markers, using TaqMan®SNP Genotyping Assays and fragment analysis were enrolled in this study. QRT-PCR and ELISA were used to analyse the expression of NOS3 mRNA and Nitric Oxide (NO) levels.

RESULTS

Two NOS3 markers were associated with susceptibility to MS and early disease development. The NOS3 rs1800779 G-allele (p = 0.04) and GG-genotype (p = 0.02) showed association with susceptibility to MS. Short NOS2 (CCTTT)n (p = 0.03) and short/long repeat (p = 0.04) genotypes also showed associations with MS. These associations were intensified by sub-division of patients into Kuwaiti Arabs and Persians (p < 0.05). The NOS3-27 bp-VNTR a-allele was associated with early MS disease onset ≤26 years (p = 0.04). The NOS3-27 bp-VNTR a/b-genotype resulted in 23% lower NO production and the NOS3-rs1800779 AA-genotype resulted in lower NOS3 expression. Haplotypes obtained from NOS2A and NOS3 showed increased susceptibility to MS. NOS1 showed no significant association with MS.

CONCLUSION

This study provides evidence for the association between selected NOS2 and NOS3 markers and MS susceptibility.

Early diagnostic biomarkers for esophageal adenocarcinoma--the current state of play

Esophageal adenocarcinoma (EAC) is one of the two most common types of esophageal cancer with alarming increase in incidence and very poor prognosis. Aiming to detect EAC early, currently high-risk patients are monitored using an endoscopic-biopsy approach. However, this approach is prone to sampling error and interobserver variability. Diagnostic tissue biomarkers related to genomic and cell-cycle abnormalities have shown promising results, although with current technology these tests are difficult to implement in the screening of high-risk patients for early neoplastic changes. Differential miRNA profiles and aberrant protein glycosylation in tissue samples have been reported to improve performance of existing tissue-based diagnostic biomarkers. In contrast to tissue biomarkers, circulating biomarkers are more amenable to population-screening strategies, due to the ease and low cost of testing. Studies have already shown altered circulating glycans and DNA methylation in BE/EAC, whereas disease-associated changes in circulating miRNA remain to be determined. Future research should focus on identification and validation of these circulating biomarkers in large-scale trials to develop in vitro diagnostic tools to screen population at risk for EAC development.

Kernel machine SNP-set testing under multiple candidate kernels

Joint testing for the cumulative effect of multiple single-nucleotide polymorphisms grouped on the basis of prior biological knowledge has become a popular and powerful strategy for the analysis of large-scale genetic association studies. The kernel machine (KM)-testing framework is a useful approach that has been proposed for testing associations between multiple genetic variants and many different types of complex traits by comparing pairwise similarity in phenotype between subjects to pairwise similarity in genotype, with similarity in genotype defined via a kernel function. An advantage of the KM framework is its flexibility: choosing different kernel functions allows for different assumptions concerning the underlying model and can allow for improved power. In practice, it is difficult to know which kernel to use a priori because this depends on the unknown underlying trait architecture and selecting the kernel which gives the lowest P-value can lead to inflated type I error. Therefore, we propose practical strategies for KM testing when multiple candidate kernels are present based on constructing composite kernels and based on efficient perturbation procedures. We demonstrate through simulations and real data applications that the procedures protect the type I error rate and can lead to substantially improved power over poor choices of kernels and only modest differences in power vs. using the best candidate kernel.

The ghrelin axis--does it have an appetite for cancer progression?

Ghrelin, the endogenous ligand for the GH secretagogue receptor (GHSR), is a peptide hormone with diverse physiological roles. Ghrelin regulates GH release, appetite and feeding, gut motility, and energy balance and also has roles in the cardiovascular, immune, and reproductive systems. Ghrelin and the GHSR are expressed in a wide range of normal and tumor tissues, and a fluorescein-labeled, truncated form of ghrelin is showing promise as a biomarker for prostate cancer. Plasma ghrelin levels are generally inversely related to body mass index and are unlikely to be useful as a biomarker for cancer, but may be useful as a marker for cancer cachexia. Some single nucleotide polymorphisms in the ghrelin and GHSR genes have shown associations with cancer risk; however, larger studies are required. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, inflammation, and angiogenesis; however, the role of ghrelin in cancer is currently unclear. Ghrelin has predominantly antiinflammatory effects and may play a role in protecting against cancer-related inflammation. Ghrelin and its analogs show promise as treatments for cancer-related cachexia. Further studies using in vivo models are required to determine whether ghrelin has a role in cancer progression.

A Comparison of Logistic Regression, Logic Regression, Classification Tree, and Random Forests to Identify Effective Gene-Gene and Gene-Environmental Interactions

Genome wide association studies (GWAS) have identified numerous single nucleotide polymorphisms (SNPs) that are associated with a variety of common human diseases. Due to the weak marginal effect of most disease-associated SNPs, attention has recently turned to evaluating the combined effect of multiple disease-associated SNPs on the risk of disease. Several recent multigenic studies show potential evidence of applying multigenic approaches in association studies of various diseases including lung cancer. But the question remains as to the best methodology to analyze single nucleotide polymorphisms in multiple genes. In this work, we consider four methods-logistic regression, logic regression, classification tree, and random forests-to compare results for identifying important genes or gene-gene and gene-environmental interactions. To evaluate the performance of four methods, the cross-validation misclassification error and areas under the curves are provided. We performed a simulation study and applied them to the data from a large-scale, population-based, case-control study.

Barrett's esophagus and esophageal cancer: an overview

Although esophageal cancer (EC) is the eighth most common cancer in several European countries, it is one of deadliest worldwide. The most frequent predisposing factor implicated in its development is Barrett's esophagus (BE), an acquired metaplastic transformation of the esophageal lining cells from normal squamous epithelium into specialised or intestinal-like columnar epithelium. The major risk factor for BE is gastroesophageal reflux disease. Although BE is in itself a benign and often asymptomatic disorder, its clinical importance stems from the recognition that it represents the main precursor lesion for the development of esophageal adenocarcinoma (AC), a tumor that is rapidly increasing especially in developed countries and is associated with a low survival rate. This paper provides an overview of the epidemiology and natural history of BE as well as of the possible pathogenetic mechanisms underlying the development of BE and its progressive transition to AC. New diagnostic tests are described, recommendations for screening and surveillance are provided and surgical and ablative procedures to treat dysplastic lesions and early neoplasia are discussed. Claimed chemopreventive agents and biomarkers that in the near future may help identify people with a higher risk of EC are also considered.

The interconnectedness of cancer cell signaling

The elegance of fundamental and applied research activities have begun to reveal a myriad of spatial and temporal alterations in downstream signaling networks affected by cell surface receptor stimulation including G protein-coupled receptors and receptor tyrosine kinases. Interconnected biochemical pathways serve to integrate and distribute the signaling information throughout the cell by orchestration of complex biochemical circuits consisting of protein interactions and covalent modification processes. It is clear that scientific literature summarizing results from both fundamental and applied scientific research activities has served to provide a broad foundational biologic database that has been instrumental in advancing our continued understanding of underlying cancer biology. This article reflects on historical advances and the role of innovation in the competitive world of grant-sponsored research.