Autoimmunity to SOX2, clinical phenotype and survival in patients with small-cell lung cancer

Bibliometric and visualized analysis of applying tumor markers in lung cancer diagnosis from 2000 to 2022

Background

Lung cancer (LC) is the leading cause of cancer-related deaths worldwide. Tumor marker (TM) detection can indicate the existence and growth of a tumor and has therefore been used extensively for diagnosing LC. Here, we conducted a bibliometric analysis to examine TM-related publications for LC diagnosis to illustrate the current state and future trends of this field, as well as to identify additional promising TMs with high sensitivity.

Methods

Publications regarding TMs in LC diagnosis were downloaded from the Web of Science Core Collection. CiteSpace was applied to perform a bibliometric analysis of journals, cocitation authors, keywords, and references related to this field. VOSviewer was used to generate concise diagrams about countries, institutions, authors, and keywords. Changes in the TM research frontier were analyzed through citation burst detection.

Results

A total of 990 studies were analyzed in this work. The collaboration network analysis revealed that the People's Republic of China, Yonsei University, and Molina R were the most productive country, institution, and scholar, respectively. Additionally, Molina R was the author with the most citations. The National Natural Science Foundation of China was the largest funding source. "Carcinoembryonic antigen (CEA) as tumor marker in lung cancer" was the top reference with the most citations, Lung Cancer was the core journal, and "serum tumor marker" experienced a citation burst over the past 5 years.

Conclusion

This bibliometric analysis of TMs in LC diagnosis presents the current trends and frontiers in this field. We summarized the research status of this field and the methods to improve the diagnostic efficacy of traditional serum TMs, as well as provided new directions and ideas for improving the LC clinical detection rate. Priority should be given to the transformation of computer-assisted diagnostic technology for clinical applications. In addition, circulating tumor cells, exosomes, and microRNAs were the current most cutting-edge TMs.

SOX2 como posible biomarcador pronóstico y diana molecular en el cáncer de pulmón: metaanálisis

OBJECTIVE

To determine the association of SOX2 with the prognosis in lung cancer, studies providing survival information were selected based on multivariate Cox regression analysis.

MATERIAL AND METHODS

PubMed, Embase, and Web of Science databases were searched to identify eligible studies before June 19, 2021. The hazard ratios (HR) with 95% confidence intervals (CI) were calculated to assess the prognostic impact of SOX2 based on multivariate Cox regression analysis. Publication bias was used to assess the risk of bias. Functional analysis of SOX2 was also conducted.

RESULTS

13 studies with a total of 2008 patients with lung cancer were included. SOX2 expression was not correlated with overall survival in lung cancer (10 studies with 1591 cases). Between-study heterogeneity was noted (I²=85.6%, p<0.0001). Subgroup analysis suggested that no correlation was found between SOX2 expression and overall survival in non-small cell lung cancer (NSCLC: eight studies with 1319 cases) and small-cell lung cancer (SCLC: two studies with 272 cases). SOX2 expression was significantly associated with worse time-to-progression (two studies with 104 cases: HR=3.50, 95% CI=1.34-9.15) and recurrence-free survival (two studies with 335 cases: HR=1.45, 95% CI=1.12-1.87) in NSCLC. Function analysis demonstrated that SOX2 was involved in DNA repair, cell cycle, regulation of stem cell population maintenance, and Hippo signaling pathway.

CONCLUSION

SOX2 may be an independent prognostic factor in time-to-progression and recurrence-free survival and may become a promising therapeutic target. More studies are essential to further our findings.

What Are the Biomarkers for Immunotherapy in SCLC?

Small-cell lung cancer (SCLC) is an aggressive malignancy that exhibits a rapid doubling time, a high growth fraction, and the early development of widespread metastases. The addition of immune checkpoint inhibitors to first-line chemotherapy represents the first significant improvement of systemic therapy in several decades. However, in contrast to its effects on non-SCLC, the advantageous effects of immunotherapy addition are modest in SCLC. In particular, only a small number of SCLC patients benefit from immune checkpoint inhibitors. Additionally, biomarkers selection is lacking for SCLC, with clinical trials largely focusing on unselected populations. Here, we review the data concerning the major biomarkers for immunotherapy, namely, programmed death ligand 1 expression and tumour mutational burden. Furthermore, we explore other potential biomarkers, including the role of the immune microenvironment in SCLC, the role of genetic alterations, and the potential links between neurological paraneoplastic syndromes, serum anti-neuronal nuclear antibodies, and outcomes in SCLC patients treated with immunotherapy.

The Prognostic Value of Sex-Determining Region Y-Box 2 and CD8+ Tumor-Infiltrating Lymphocytes in Limited-Stage Small-Cell Lung Cancer

BACKGROUND

Sex-determining region Y-box 2 (SOX2) is a transcriptional factor that drives embryonic stem cells to neuroendocrine cells in lung development and is highly expressed in small-cell lung cancer (SCLC). However, the prognostic role of SOX2 and its relationship with tumor-infiltrating lymphocytes (TILs) has not been determined in SCLC. Herein, we assessed the expression of SOX2 and CD8+ TILs to obtain insights into the prognostic role of SOX2 and CD8+ TILs in limited-stage (LS)-SCLC.

METHODS

A total of 75 patients with LS-SCLC was enrolled. The SOX2 expression and CD8+ TILs were evaluated by immunohistochemistry.

RESULTS

High SOX2 and CD8+ TIL levels were identified in 52 (69.3%) and 40 (53.3%) patients, respectively. High SOX2 expression was correlated with increased density of CD8+ TILs (p = 0.041). Unlike SOX2, high CD8+ TIL numbers were associated with significantly longer progression-free survival (PFS; 13.9 vs. 8.0 months, p = 0.014). Patients with both high SOX2 expression and CD8+ TIL numbers (n = 29, 38.7%) had significantly longer PFS and overall survival (OS) compared to those from the other groups (median PFS 19.3 vs. 8.4 months; p = 0.002 and median OS 35.7 vs. 17.4 months; p = 0.004, respectively). Multivariate Cox regression analysis showed that the combination of high SOX2 expression and CD8+ TIL levels was an independent good prognostic factor for OS (HR = 0.471, 95% CI, 0.250-0.887, p = 0.02) and PFS (HR = 0.447, 95% CI, 0.250-0.801, p = 0.007) in SCLC.

CONCLUSIONS

Evaluation of the combination of SOX2 and CD8+ TIL levels may be of a prognostic value in LS-SCLC.

[Immunotherapy Advances in Small Cell Lung Cancer]

Small cell lung cancer (SCLC) is a "refractory cancer" characterized by rapid growth and extensive early metastasis. About 70% of patients are already in the extensive stage at the time of diagnosis. Despite the high response rate to platinum-contained first-line chemotherapy, almost all patients subsequently experienced inevitable recurrence and had poor response to second-line treatment. The high mutation load and immunogenicity of SCLC suggest that immunotherapy may be effective for SCLC patients. Over the past few years, several clinical trials have evaluated the efficacy of checkpoint inhibitors [mainly cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and programmed death 1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitors] in SCLC patients and demonstrated promising survival prospects. This article reviewed the clinical studies of immune checkpoint inhibitors (ICIs) in the first-line, maintenance and second or more line treatment of SCLC. Besides, predictive biomarkers were discussed to select suitable patients for immunotherapy effectively.

Specificity and application of SOX2 antibody

Sox2 is known to play an important role in maintaining the totipotency and self-renewal of embryonic stem cells. The purpose of this study was to prepare an anti-chicken Sox2 polyclonal antibody using prokaryotic expression techniques, to evaluate its specificity and to use it to investigate the expression and distribution of Sox2 in the chicken brain and lungs. The chicken Sox2 gene was amplified and subcloned to a pET-30a vector to construct a prokaryotic expression vector, pET-Sox2. A His-Sox2 fusion protein was expressed, purified, and used to prepare an antichicken Sox2 polyclonal antibody. Western blotting revealed that the antichicken Sox2 antibody could specifically bind not only to the purified His-Sox2 fusion protein but also to the endogenous Sox2 protein in the testes of chicken, showing a distinct dose-dependent relationship between antigen and Sox2 antibody. Indirect immunofluorescent staining of Sox2-overexpressing cells showed strong nuclear and diffuse cytoplasmic immunoreactivity for Sox2 in the antichicken Sox2 antibody-staining cells. A CRISPR/Cas9 effector system-mediated Sox2 knockdown assay indicated that Sox2 expression in HEK 293T cells was downregulated in the presence of doxycycline but upregulated in the absence of doxycycline. In addition, cryosectioning and immunohistochemical staining illustrated that most spermatogonia in the seminiferous tubules, and a small number of Sertoli and Leydig cells, were positive for Sox2. The antichicken Sox2 antibody was also successfully used to investigate the expression and distribution of Sox2 in the chicken cerebellar cortex, optic tectum, cerebral cortex, and lungs. The results of this study confirmed the specificity of the antichicken Sox2 polyclonal antibody, which will be available for the study of biological functions of the chicken Sox2 gene and the self-renewal mechanisms of chicken pluripotent stem cells.

SOX2 knockdown inhibits the migration and invasion of basal cell carcinoma cells by targeting the SRPK1-mediated PI3K/AKT signaling pathway

Basal cell carcinoma (BCC) is the most common type of human skin cancer, which is driven by the aberrant activation of Hedgehog signaling. Previous evidence indicated that sex determining region Y-box 2 (SOX2) is associated with the tumor metastasis. However, the expression and role of SOX2 in BCC remain unknown. Therefore, the aim of the current study was to analyze the possible mechanism of SOX2 in the progression of BCC. The levels of SOX2 in BCC cells were detected by reverse transcription-quantitative polymerase chain reaction. Transwell assays were also used to determine the migration and invasion of BCC cells. Immunoblotting and immunofluorescence were used for analyzing the role of SOX2 knockdown in the serine-arginine protein kinase 1 (SRPK1)-mediated phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway in BCC cells. The results demonstrated that SOX2 is overexpressed in BCC tissues and cells. In addition, SOX2 knockdown inhibited the migration and invasion of BCC cells, and the epithelial-mesenchymal transition (EMT) progress of BCC cells. It was also observed that SOX2 knockdown decreased SRPK1 expression, which further led to the downregulation of PI3K and AKT expression levels in BCC cells. Furthermore, SRPK1 transfection or PI3K/AKT pathway activation abolished the inhibitory effects of SOX2 knockdown on the migration, invasion and EMT progress of BCC cells. In conclusion, these results indicated that SOX2 may potentially serve as a target for BCC therapy by targeting the SRPK1-mediated PI3K/AKT signaling pathway.

Serum pleiotrophin as a diagnostic and prognostic marker for small cell lung cancer

Pleiotrophin (PTN) is involved in tumour progression, angiogenesis and metastasis. The purpose of this study was to investigate the expression level of PTN in the serum of patients with small cell lung cancer (SCLC) and to explore the clinical significance of PTN. Serum samples from 128 patients with SCLC, 120 healthy volunteers (HV) and 60 patients with benign lung disease (BLD) were collected. The levels of serum PTN were determined with ELISA and its correlation with the clinical data was examined. The serum PTN levels in SCLC patients were significantly higher than that in BLD patients (P < 0.05) or HV (P < 0.05). With a cutoff value of 258.18 ng/mL, the sensitivity and specificity of PTN to SCLC patients and BLD patients, SCLC patients and HV were 79.2% and 91.7%, 86.7% and 95.8% respectively. An area under the curve for all stages of SCLC resulting from PTN, which was significantly better than the other tumour markers tested including progastrin‐releasing peptide and neuron‐specific enolase. High serum PTN levels appear to correlate with poor survival in patients with SCLC. These results suggest that PTN levels in the serum could be a new effective biomarker for the diagnosis and prognosis of SCLC.

The utility of anti-SOX2 antibodies for cancer prediction in patients with paraneoplastic neurological disorders

Antibodies to SOXB1 proteins in patients with paraneoplastic disorders are associated with small-cell lung cancer (SCLC), particularly in Lambert-Eaton myasthenic syndrome (LEMS). We aimed to establish if SOX2 antibodies could be used to identify SCLC and other tumours found in a range of paraneoplastic disorders and controls. SOX2 antibodies were detectable in 61% of patients with LEMS-SCLC, and in other paraneoplastic disorders, such as opsoclonus-myoclonus and paraneoplastic cerebellar degeneration, only when there was an underlying SCLC. SOX2 antibodies are specific (>90%) markers for SCLC, but are rarely found in patients with other tumours, whether neurological symptoms are present or not.

Transcriptional deregulation underlying the pathogenesis of small cell lung cancer

The discovery of recurrent alterations in genes encoding transcription regulators and chromatin modifiers is one of the most important recent developments in the study of the small cell lung cancer (SCLC) genome. With advances in models and analytical methods, the field of SCLC biology has seen remarkable progress in understanding the deregulated transcription networks linked to the tumor development and malignant progression. This review will discuss recent discoveries on the roles of RB and P53 family of tumor suppressors and MYC family of oncogenes in tumor initiation and development. It will also describe the roles of lineage-specific factors in neuroendocrine (NE) cell differentiation and homeostasis and the roles of epigenetic alterations driven by changes in NFIB and chromatin modifiers in malignant progression and chemoresistance. These recent findings have led to a model of transcriptional network in which multiple pathways converge on regulatory regions of crucial genes linked to tumor development. Validation of this model and characterization of target genes will provide critical insights into the biology of SCLC and novel strategies for tumor intervention.

Assessment of neuronal autoantibodies in patients with small cell lung cancer treated with chemotherapy with or without ipilimumab

Small-cell lung cancer (SCLC) is often associated with paraneoplastic syndromes. To assess the role of anti-neuronal autoantibodies (NAAs) as biomarkers of treatment outcome, we assessed NAAs in serial samples from SCLC patients treated with chemoimmunotherapy compared to chemotherapy alone. We evaluated 2 cohorts: in cohort 1 (C1), 47 patients received standard platinum/etoposide, and in cohort 2 (C2), 38 patients received ipilimumab, carboplatin and etoposide. Serum samples at baseline and subsequent time points were analyzed for the presence of NAAs. NAAs were detected at baseline in 25 patients (53.2%) in C1 and in 20 patients (52.6%) in C2 (most frequently anti-Sox1). NAA at baseline was associated with limited disease (75% vs 50%; p: 0.096) and better overall survival (15.1 m vs 11.7 m; p: 0.032) in C1. Thirteen patients (28.9%) showed 2 or more reactivities before treatment; this was associated with worse PFS (5.5 m vs 7.3 m; p: 0.005) in patients treated with chemoimmunotherapy. NAA titers decreased after therapy in 68.9% patients, with no differential patterns of change between cohorts. Patients whose NAA titer decreased after treatment, showed longer OS [18.5 m (95% CI: 15.8 - 21.2)] compared with those whose NAA increased [12.3 m (95% CI: 8.1 - 16.5; p 0.049)], suggesting that antibody levels correlate to tumor load. Our findings reinforce the role of NAAs as prognostic markers and tumor activity/burden in SCLC, warrant further investigation in their predictive role for immunotherapy and raise concern over the use of immunotherapy in patients with more than one anti-NAA reactivity.

Serum tumor-associated autoantibodies as diagnostic biomarkers for lung cancer: A systematic review and meta-analysis

OBJECTIVE

We performed a comprehensive review and meta-analysis to evaluate the diagnostic values of serum single and multiplex tumor-associated autoantibodies (TAAbs) in patients with lung cancer (LC).

METHODS

We searched the MEDLINE and EMBASE databases for relevant studies investigating serum TAAbs for the diagnosis of LC. The primary outcomes included sensitivity, specificity and accuracy of the test.

RESULTS

The systematic review and meta-analysis included 31 articles with single autoantibody and 39 with multiplex autoantibodies. Enzyme-linked immunosorbent assay (ELISA) was the most common detection method. For the diagnosis of patients with all stages and early-stage LC, different single or combinations of TAAbs demonstrated different diagnostic values. Although individual TAAbs showed low diagnostic sensitivity, the combination of multiplex autoantibodies offered relatively high sensitivity. For the meta-analysis of a same panel of autoantibodies in patients at all stages of LC, the pooled results of the panel of 6 TAAbs (p53, NY-ESO-1, CAGE, GBU4-5, Annexin 1 and SOX2) were: sensitivity 38% (95% CI 0.35-0.40), specificity 89% (95% CI 0.86-0.91), diagnostic accuracy 65.9% (range 62.5-81.8%), AUC 0.52 (0.48-0.57), while the summary estimates of 7 TAAbs (p53, CAGE, NY-ESO-1, GBU4-5, SOX2, MAGE A4 and Hu-D) were: sensitivity 47% (95% CI 0.34-0.60), specificity 90% (95% CI 0.89-0.92), diagnostic accuracy 78.4% (range 67.5-88.8%), AUC 0.90 (0.87-0.93). For the meta-analysis of the same panel of autoantibodies in patients at early-stage of LC, the sensitivities of both panels of 7 TAAbs and 6 TAAbs were 40% and 29.7%, while their specificities were 91% and 87%, respectively.

CONCLUSIONS

Serum single or combinations of multiplex autoantibodies can be used as a tool for the diagnosis of LC patients at all stages or early-stage, but the combination of multiplex autoantibodies shows a higher detection capacity; the diagnostic value of the panel of 7 TAAbs is higher than the panel of 6 TAAbs, which may be used as potential biomarkers for the early detection of LC.

Outcome and Biomarker Analysis from a Multicenter Phase 2 Study of Ipilimumab in Combination with Carboplatin and Etoposide as First-Line Therapy for Extensive-Stage SCLC

OBJECTIVES

Our aim was to evaluate the safety and efficacy of ipilimumab combined with standard first-line chemotherapy for patients with extensive-stage SCLC.

METHODS

Patients with chemotherapy-naive extensive-stage SCLC were treated with carboplatin and etoposide for up to six cycles. Ipilimumab, 10 mg/kg, was given on day 1 of cycles 3 to 6 and every 12 weeks. Response was assessed by the Response Evaluation Criteria in Solid Tumors (RECIST), version 1.0, and immune-related response criteria. The primary end point was 1-year progression-free survival (PFS) according to RECIST. Secondary end points included PFS according to immune-related PFS and overall survival. Autoantibody serum levels were evaluated and correlated with clinical outcomes.

RESULTS

A total of 42 patients were enrolled between September 2011 and April 2014; 39 were evaluable for safety and 38 for efficacy. Six of 38 patients (15.8% [95% confidence interval (CI): 7.4-30.4]) were alive and progression-free at 1-year by RECIST. Median PFS was 6.9 months (95% CI: 5.5-7.9). Median immune-related PFS was 7.3 months (95% CI: 5.5-8.8). Median overall survival was 17.0 months (95% CI: 7.9-24.3). Of the patients evaluable for response, 21 of 29 (72.4%) achieved an objective response by RECIST and 28 of 33 (84.8%) achieved an objective response by the immune-related response criteria. All patients experienced at least one adverse event; at least one grade 3 or higher toxicity developed in 35 of 39 patients (89.7%); in 27 patients (69.2%) this was related to ipilimumab. Five deaths were reported to be related to ipilimumab. Positivity of an autoimmune profile at baseline was associated with improved outcomes and severe neurological toxicity.

CONCLUSIONS

Ipilimumab in combination with carboplatin and etoposide might benefit a subgroup of patients with advanced SCLC. Autoantibody analysis correlates with treatment benefit and toxicity and warrants further investigation.

Cancer Stem Cells, Epithelial to Mesenchymal Markers, and Circulating Tumor Cells in Small Cell Lung Cancer

BACKGROUND

Small cell lung cancer (SCLC) has a poor prognosis, and even with localized (limited) disease, the 5-year survival has only been around 20%. Elevated levels of circulating tumor cells (CTCs) have been associated with a worse prognosis, and markers of cancer stem cells (CSCs) and epithelial to mesenchymal transition have been associated with increased chemoresistance and metastatic spread in SCLC.

PATIENTS AND METHODS

The biopsy specimens of 38 SCLC patients were used for marker evaluation by immunohistochemistry. The markers for CSCs were CD44 and SOX2. The markers for epithelial to mesenchymal transition were E-cadherin, epithelial cell adhesion molecule, cytokeratins 8, 18, and 19, vimentin, and c-MET. Staining was scored as low (weak) or high (strong) intensity for SOX2, epithelial cell adhesion molecule, cytokeratins 8, 18, and 19, and c-MET and using the immunoreactive score for CD44, E-cadherin, and vimentin, expressed as low or high expression.

RESULTS

High expression of c-MET (c-MET^H) and low expression of E-cadherin (E-cad^L) showed a trend toward a better prognosis (P = .07 and P = .09, respectively). The combination of c-MET^H and E-cad^L resulted in significantly better survival (P = .007). The tested markers were not associated with CTCs, although a trend was seen for c-MET^HE-cad^L (P = .09) with low CTCs. The CSC markers SOX2 and CD44 were not associated with overall survival in this patient cohort.

CONCLUSION

SCLC with a mesenchymal-like phenotype (c-MET^HE-cad^L) is associated with longer survival and showed a trend toward lower CTCs.

The non-small cell lung cancer immune contexture. A major determinant of tumor characteristics and patient outcome

Solid tumors, beyond mere accumulation of cancer cells, form a complex ecosystem consisting of normal epithelial cells, fibroblasts, blood and lymphatic vessels, structural components, and infiltrating hematopoietic cells including myeloid and lymphoid elements that impact tumor growth, tumor spreading, and clinical outcome. The composition of the immune microenvironment is diverse, including various populations of T cells, B cells, dendritic cells, natural killer cells, myeloid-derived suppressor cells, neutrophils, or macrophages. The immune contexture describes the density, location, and organization of these immune cells within solid tumors. In lung cancer, which is the deadliest type of cancer, and particularly in non-small cell lung cancer, its most prevalent form, reports have described some of the interactions between the tumor and the host. These data, in addition to articles on various types of tumors, provide a greater understanding of the tumor-host microenvironment interaction and stimulate the development of prognostic and predictive biomarkers, the identification of novel target antigens for therapeutic intervention, and the implementation of tools for long-term management of patients with cancer.

Autologous anti-SOX2 antibody responses reflect intensity but not frequency of antigen expression in small cell lung cancer

BACKGROUND

Anti-SOX2 antibody responses are observed in about 10 to 20% of small cell lung cancer (SCLC) patients. The aim of this study was to determine whether such responses reflect a particular pattern of SOX2 protein expression in the tumor and whether this pattern associates with clinical outcome.

METHODS

Paraffin embedded tumor tissues, obtained from SCLC patients who had no evidence of paraneoplastic autoimmune degeneration, were evaluated for SOX2 expression by immunohistochemistry for both intensity and extent of staining. Sera from the same patients were tested for autologous antibodies against recombinant SOX2 by enzyme-linked immunosorbent assay (ELISA). Correlates between overall survival and various clinical parameters including SOX2 staining and serology were determined.

RESULTS

SOX2 protein expression was observed in tumor tissue in 89% of patients. Seventeen patients (29%) were seropositive for SOX2 antibodies and, in contrast to SOX2 staining, the presence of antibody correlated with limited disease stage (p = 0.05). SOX2 seropositivity showed a significant association with the intensity of SOX2 staining in the tumor (p = 0.02) but not with the frequency of SOX2 expressing cells.

CONCLUSION

Anti-SOX2 antibodies associate with better prognosis (limited stage disease) while SOX2 protein expression does not; similar to reports from some earlier studies. Our data provides an explanation for this seemingly contrasting data for the first time as SOX2 antibodies can be observed in patients whose tumors contain relatively few but strongly staining cells, thus supporting the possible presence of active immune-surveillance and immune-editing targeting SOX2 protein in this tumor type.

SOX15 and other SOX family members are important mediators of tumorigenesis in multiple cancer types

SOX genes are transcription factors with important roles in embryonic development and carcinogenesis. The SOX family of 20 genes is responsible for regulating lineage and tissue specific gene expression patterns, controlling numerous developmental processes including cell differentiation, sex determination, and organogenesis. As is the case with many genes involved in regulating development, SOX genes are frequently deregulated in cancer. In this perspective we provide a brief overview of how SOX proteins can promote or suppress cancer growth. We also present a pan-cancer analysis of aberrant SOX gene expression and highlight potential molecular mechanisms responsible for their disruption in cancer. Our analyses indicate the prominence of SOX deregulation in different cancer types and reveal potential roles for SOX genes not previously described in cancer. Finally, we summarize our recent identification of SOX15 as a candidate tumor suppressor in pancreatic cancer and propose several research avenues to pursue to further delineate the emerging role of SOX15 in development and carcinogenesis.

[The expression and significance of stem cell transcription factor Sox2 in lung carcinoma]

背景与目的

转录因子Sox2维持干细胞的全能性，参与肿瘤干细胞的自我更新，在多种肿瘤的发生发展中发挥重要作用。本研究旨在探讨Sox2及Sox2自身抗体（Sox2-Ab）在非小细胞肺癌（non-small cell lung cancer, NSCLC）患者组织及血清中的表达和意义。

方法

荧光定量PCR及免疫组化法检测58例NSCLC、16例其他肿瘤和20例正常肺组织标本中Sox2基因及蛋白表达，ELISA法检测30例NSCLC患者和30例健康体检者血清Sox2-Ab水平，结合NSCLC临床病理特点进行数据分析。

结果

肺癌组织中Sox2 mRNA水平及蛋白阳性表达率均高于其他肿瘤及正常肺组织，差异均有统计学意义（P < 0.01），且Sox2 mRNA表达增高同肺癌患者病理类型及肿瘤大小有关，与性别、年龄、肿瘤分化程度和淋巴结转移等无关。血清Sox2-Ab水平在NSCLC患者和正常体检者差异无统计学意义。

结论

Sox2在NSCLC中有较高的表达，与病理类型、肿瘤大小密切相关，Sox2可能成为肺癌新的标志物及治疗靶点。

Serum YKL-40 level is associated with the chemotherapy response and prognosis of patients with small cell lung cancer

This study was to explore the association between the serum YKL-40 level and the clinical characteristics, the response to chemotherapy and prognosis in small cell lung cancer (SCLC). Serum YKL-40 levels were detected and compared in 120 patients with SCLC pre- and post-chemotherapy, and in 40 healthy controls. Receiver operating characteristics (ROC) curves were adopted for diagnosis and calculation of area under ROC curve in SCLC. The Kaplan–Meier method, univariate and multivariate Cox regression analysis were used to analyze the correlation between pre-chemotherapy serum YKL-40 levels and progression-free survival (PFS) and overall survival (OS). The pre-chemotherapy serum YKL-40 levels were significantly higher than those of the controls (p<0.001). The post-chemotherapy serum YKL-40 levels in the SCLC cases were lower than pre-chemotherapy serum YKL-40 levels in these cases (p = 0.026). The patients with high serum YKL-40 showed a poorer response to chemotherapy than those patients with low serumYKL-40 (p = 0.031). Univariate analysis revealed that SCLC patients with high serum YKL-40 had a shorter PFS and OS than those with low serum YKL-40 (HR of 1.74, p = 0.033; HR of 1.33, p = 0.001). Cox multivariate analysis indicated that YKL-40 was an independent prognostic indicator of PFS and OS (HR of 1.12, p = 0.029; HR of 1.84, p = 0.025). Kaplan–Meier survival curves further confirmed that patients with low serum YKL-40 have longer PFS and OS (p = 0.016 and p = 0.041, respectively). These results suggest that YKL-40 is a potential prognostic marker of chemotherapy response in SCLC.

Pathogenic immune mechanisms at the neuromuscular synapse: the role of specific antibody-binding epitopes in myasthenia gravis

Autoantibodies against three different postsynaptic antigens and one presynaptic antigen at the neuromuscular junction are known to cause myasthenic syndromes. The mechanisms by which these antibodies cause muscle weakness vary from antigenic modulation and complement-mediated membrane damage to inhibition of endogenous ligand binding and blocking of essential protein-protein interactions. These mechanisms are related to the autoantibody titre, specific epitopes on the target proteins and IgG autoantibody subclass. We here review the role of specific autoantibody-binding epitopes in myasthenia gravis, their possible relevance to the pathophysiology of the disease and potential implications of epitope mapping knowledge for new therapeutic strategies.

A novel heterozygous SOX2 mutation causing congenital bilateral anophthalmia, hypogonadotropic hypogonadism and growth hormone deficiency

Heterozygous de novo mutations in SOX2 have been reported in approximately 10-20% of patients with unilateral or bilateral anophthalmia or microphthalmia. An additional phenotype of hypopituitarism, with anterior pituitary hypoplasia and hypogonadotropic hypogonadism, has been reported in patients carrying SOX2 alterations. We report a novel heterozygous mutation in the SOX2 gene in a male affected with congenital bilateral anophthalmia, hypogonadotrophic hypogonadism and growth hormone deficiency. The mutation we describe is a cytosine deletion in position 905 (c905delC) which causes frameshift and an aberrant C-terminal domain. Our report highlights the fact that subjects affected with eye anomalies and harboring SOX2 mutations are at high risk for gonadotropin deficiency, which has important implications for their clinical management.

Serum markers in small cell lung cancer: opportunities for improvement

Lung cancer is one of the leading causes of death from malignancy worldwide. In particular small cell lung cancers, which comprise about 15-20% of all lung cancers, are extremely aggressive and cure rates are extremely low. Therefore, new treatment modalities are needed and detection at an early stage of disease, as well as adequate monitoring of treatment response is essential in order to improve outcome. In this respect, the use of non-invasive tools for screening and monitoring has gained increasing interest and the clinical applicability of reliable, tumor-related substances that can be detected as tumor markers in easily accessible body fluids is subject of intense investigation. Some of these indicators, such as high LDH levels in serum as a reflection of the disease, have been in use for a long time as a general tumor marker. To allow for improved monitoring of the efficacy of new therapeutic modalities and for accurate subtyping, there is a strong need for specific and sensitive markers that are more directly related to the biology and behavior of small cell lung cancer. In this review the current status of these potential markers, like CEA, NSE, ProGRP, CK-BB, SCC, CgA, NCAM and several cytokeratins will be critically analyzed with respect to their performance in blood based assays. Based on known cleavage sites for cytoplasmic and extracellular proteases, a prediction of stable fragments can be obtained and used for optimal test design. Furthermore, insight into the synthesis of specific splice variants and neo-epitopes resulting from protein modification and cleavage, offers further opportunities for improvement of tumor assays. Finally, we discuss the possibility that detection of SCLC related autoantibodies in paraneoplastic disease can be used as a very early indicator of SCLC.

SOX1 antibodies in Lambert-Eaton myasthenic syndrome and screening for small cell lung carcinoma

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder of the neuromuscular synapse. About half of LEMS patients have an associated small cell lung carcinoma (SCLC), which is usually detected after diagnosis of LEMS. This short review summarizes clinical and serological markers shown to predict the presence of SCLC in LEMS patients. SOX1 antibodies are a specific marker for SCLC-LEMS but they are also found in SCLC patients without paraneoplastic neurological syndromes. No relation to any clinical characteristic or survival effect has been found for SOX1-positive patients. Several clinical markers also discriminate between SCLC-LEMS and nontumor LEMS. Detailed analysis of these clinical and demographic characteristics from two independent patient cohorts has led to development of the DELTA-P score. This prediction model has provided for a simple clinical tool to indicate the presence of SCLC early in the course of the disease. The DELTA-P score can be used to guide tumor screening in individual patients.

The multiple roles for Sox2 in stem cell maintenance and tumorigenesis

The Sry-containing protein Sox2 initially was known to regulate the self-renewal of the mouse and human embryonic stem cells (ESCs). It is also important for the maintenance of stem cells in multiple adult tissues including the brain and trachea, and it is one of the key transcription factors for establishing induced pluripotent stem cells. Recently, overexpression and gene amplification of Sox2 have been associated with the development of squamous cell carcinoma in multiple tissues such as the lung and esophagus. These different roles for Sox2 involve a complicated regulatory networks consisting of microRNAs, kinases and signaling molecules. While the levels of Sox2 are modulated transcriptionally and translationally, post-translational modification is also important for the various functions of Sox2. In clinics, high levels of Sox2 are correlated with poor prognosis and increased proliferation of cancer stem cells. Therefore targeting Sox2 can be potentially explored for a new therapeutic avenue to treat cancers. This review will focus on the different roles for Sox2 in stem cell maintenance and its oncogenic roles in the context of signal transcription and microRNA regulation. We will also review the main upstream and downstream targets of Sox2, which can be potentially used as therapeutic measures to treat cancer with abnormal levels of Sox2.

True 3q chromosomal amplification in squamous cell lung carcinoma by FISH and aCGH molecular analysis: impact on targeted drugs

Squamous lung carcinoma lacks specific “ad hoc” therapies. Amplification of chromosome 3q is the most common genomic aberration and this region harbours genes having role as novel targets for therapeutics. There is no standard definition on how to score and report 3q amplification. False versus true 3q chromosomal amplification in squamous cell lung carcinoma may have tremendous impact on trials involving drugs which target DNA zones mapping on 3q. Forty squamous lung carcinomas were analyzed by FISH to assess chromosome 3q amplification. aCGH was performed as gold-standard to avoid false positive amplifications. Three clustered patterns of fluorescent signals were observed. Eight cases out of 40 (20%) showed ≥8 3q signals. Twenty out of 40 (50%) showed from 3 to 7 signals. The remaining showed two fluorescent signals (30%). When corrected by whole chromosome 3 signals, only cases with ≥8 signals maintained a LSI 3q/CEP3 ratio >2. Only the cases showing 3q amplification by aCGH (+3q25.3−3q27.3) showed ≥8 fluorescent signals at FISH evidencing a 3q/3 ratio >2. The remaining cases showed flat genomic portrait at aCGH on chromosome 3. We concluded that: 1) absolute copy number of 3q chromosomal region may harbour false positive interpretation of 3q amplification in squamous cell carcinoma; 2) a case results truly “amplified for chromosome 3q” when showing ≥8 fluorescent 3q signals; 3) trials involving drugs targeting loci on chromosome 3q in squamous lung carcinoma therapy have to consider false versus true 3q chromosomal amplification.

The role of Sox genes in lung morphogenesis and cancer

The human lung consists of multiple cell types derived from early embryonic compartments. The morphogenesis of the lung, as well as the injury repair of the adult lung, is tightly controlled by a network of signaling pathways with key transcriptional factors. Lung cancer is the third most cancer-related death in the world, which may be developed due to the failure of regulating the signaling pathways. Sox (sex-determining region Y (Sry) box-containing) family transcriptional factors have emerged as potent modulators in embryonic development, stem cells maintenance, tissue homeostasis, and cancerogenesis in multiple processes. Recent studies demonstrated that the members of the Sox gene family played important roles in the development and maintenance of lung and development of lung cancer. In this context, we summarize our current understanding of the role of Sox family transcriptional factors in the morphogenesis of lung, their oncogenic potential in lung cancer, and their potential impact in the diagnosis, prognosis, and targeted therapy of lung cancer.

SOX2 autoantibodies as noninvasive serum biomarker for breast carcinoma

BACKGROUND

A clear association has been established between antibodies to the transcription factor sex-determining region Y (SRY)-box 2 (SOX2) and small cell lung cancer. In light of the pathologic role of SOX2 and its aberrant expression in breast cancer, we measured serum SOX2 autoantibodies (SOX2-Abs) in breast cancer patients.

METHODS

The presence of SOX2-Abs was determined by an indirect enzyme-linked immunosorbent assay (ELISA) in sera from 282 patients with breast cancer, 78 patients with benign breast disease, and 194 healthy women.

RESULTS

SOX2-Abs were more prevalent in patients with breast cancer (18.4%) compared with healthy women (2.6%, P < 0.0001), and patients with benign breast disease (6.4%, P = 0.011). The concentrations of circulating SOX2-Abs were found to discriminate between breast cancer patients and healthy controls (P < 0.001) and between breast cancer patients and those with benign breast disease (P < 0.001). In addition, measurement of SOX2-Abs was more effective than assays of serum tissue polypeptide-specific antigen, carcinoembryonic antigen, carbohydrate antigen (CA) 125, and CA 15-3 in distinguishing between malignant and benign breast disease. In breast cancer patients, the prevalence of SOX2-Abs was associated with a higher tumor grade (P = 0.021) and positive nodal status (P = 0.021).

CONCLUSION

The presence of SOX2-Abs in breast cancer may be of clinical value.

IMPACT

This study provides the first evidence for the presence of circulating SOX2-Abs in breast cancer and shows their potential clinical application.

Patients with multiple myeloma develop SOX2-specific autoantibodies after allogeneic stem cell transplantation

The occurrence of SOX2-specific autoantibodies seems to be associated with an improved prognosis in patients with monoclonal gammopathy of undetermined significance (MGUS). However, it is unclear if SOX2-specific antibodies also develop in established multiple myeloma (MM). Screening 1094 peripheral blood (PB) sera from 196 MM patients and 100 PB sera from healthy donors, we detected SOX2-specific autoantibodies in 7.7% and 2.0% of patients and donors, respectively. We identified SOX2_211–230 as an immunodominant antibody-epitope within the full protein sequence. SOX2 antigen was expressed in most healthy tissues and its expression did not correlate with the number of BM-resident plasma cells. Accordingly, anti-SOX2 immunity was not related to SOX2 expression levels or tumor burden in the patients' BM. The only clinical factor predicting the development of anti-SOX2 immunity was application of allogeneic stem cell transplantation (alloSCT). Anti-SOX2 antibodies occurred more frequently in patients who had received alloSCT (n = 74). Moreover, most SOX2-seropositive patients had only developed antibodies after alloSCT. This finding indicates that alloSCT is able to break tolerance towards this commonly expressed antigen. The questions whether SOX2-specific autoantibodies merely represent an epiphenomenon, are related to graft-versus-host effects or participate in the immune control of myeloma needs to be answered in prospective studies.

SOX2 haploinsufficiency is associated with slow progressing hypothalamo-pituitary tumours

SOX2 is an early developmental transcription factor and marker of stem cells that has recently been implicated in the development of the pituitary gland. Heterozygous SOX2 mutations have been described in patients with hypopituitarism and severe ocular abnormalities. In the majority of published cases, the pituitary gland is either small or normal in size. Here, we report two unrelated patients with SOX2 haploinsufficiency (a heterozygous gene deletion and a novel c.143TC>AA/p.F48X mutation) who developed nonprogressive pituitary tumors of early onset, suggesting a congenital etiology. The truncating mutation resulted in significant loss of function and impaired nuclear localization of the mutant protein, in addition to a failure to repress β-catenin transcriptional activity in vitro. This is the first indication that SOX2 haploinsufficiency is implicated in the generation of pituitary tumors with distinct clinical characteristics, possibly mediated via its effects on the Wnt signaling pathway.

Small-cell lung cancer-associated autoantibodies: potential applications to cancer diagnosis, early detection, and therapy

Small-cell lung cancer (SCLC) is the most aggressive lung cancer subtype and lacks effective early detection methods and therapies. A number of rare paraneoplastic neurologic autoimmune diseases are strongly associated with SCLC. Most patients with such paraneoplastic syndromes harbor high titers of antibodies against neuronal proteins that are abnormally expressed in SCLC tumors. These autoantibodies may cross-react with the nervous system, possibly contributing to autoimmune disease development. Importantly, similar antibodies are present in many SCLC patients without autoimmune disease, albeit at lower titers. The timing of autoantibody development relative to cancer and the nature of the immune trigger remain to be elucidated. Here we review what is currently known about SCLC-associated autoantibodies, and describe a recently developed mouse model system of SCLC that appears to lend itself well to the study of the SCLC-associated immune response. We also discuss potential clinical applications for these autoantibodies, such as SCLC diagnosis, early detection, and therapy.

Gender-related disparities in non-small cell lung cancer

Epidemiological studies clearly outline some disparities in cancer onset, progression as well as prognosis and therapeutic response between sexes. In particular, in lung cancer, the leading cause of cancer death, at least in Western countries, a gender disparity appears now to emerge, especially for non-small cell lung cancer (NSCLC). Such a disparity is apparently due to a variety of mechanisms, ranging from genetic and epigenetic differences to gender-specific lifestyle as well as to behavioral causes and, clearly, to sex hormones activity. Here we briefly recapitulate gender differences in terms of risk factors, histopathological features and pathogenetic mechanisms in NSCLC, and hypothesize that a gender-oriented pharmacology could beneficially impact on innovative therapeutic strategies.

Clinical validation of an autoantibody test for lung cancer

Background: Autoantibodies may be present in a variety of underlying cancers several years before tumours can be detected and testing for their presence may allow earlier diagnosis. We report the clinical validation of an autoantibody panel in newly diagnosed patients with lung cancer (LC).

Patients and methods: Three cohorts of patients with newly diagnosed LC were identified: group 1 (n = 145), group 2 (n = 241) and group 3 (n = 269). Patients were individually matched by gender, age and smoking history to a control individual with no history of malignant disease. Serum samples were obtained after diagnosis but before any anticancer treatment. Autoantibody levels were measured against a panel of six tumour-related antigens (p53, NY-ESO-1, CAGE, GBU4-5, Annexin 1 and SOX2). Assay sensitivity was tested in relation to demographic variables and cancer type/stage.

Results: The autoantibody panel demonstrated a sensitivity/specificity of 36%/91%, 39%/89% and 37%/90% in groups 1, 2 and 3, respectively, with good reproducibility. There was no significant difference between different LC stages, indicating that the antigens included covered the different types of LC well.

Conclusion: This assay confirms the value of an autoantibody panel as a diagnostic tool and offers a potential system for monitoring patients at high risk of LC.

Promotion of direct reprogramming by transformation-deficient Myc

Induced pluripotent stem cells (iPSCs) are generated from mouse and human fibroblasts by the introduction of three transcription factors: Oct3/4, Sox2, and Klf4. The proto-oncogene product c-Myc markedly promotes iPSC generation, but also increases tumor formation in iPSC-derived chimeric mice. We report that the promotion of iPSC generation by Myc is independent of its transformation property. We found that another Myc family member, L-Myc, as well as c-Myc mutants (W136E and dN2), all of which have little transformation activity, promoted human iPSC generation more efficiently and specifically compared with WT c-Myc. In mice, L-Myc promoted germline transmission, but not tumor formation, in the iPSC-derived chimeric mice. These data demonstrate that different functional moieties of the Myc proto-oncogene products are involved in the transformation and promotion of directed reprogramming.