Xiangqian Su

Reproducible copy number variation patterns among single circulating tumor cells of lung cancer patients

Significance In a few milliliters of blood from a cancer patient, one can isolate a few circulating tumor cells (CTCs). Originating from the primary tumor, CTCs seed metastases, which account for the majority of cancer-related deaths. We demonstrate the analyses of the whole genome of single CTCs, which are highly needed for personalized treatment. We discovered that copy number variations (CNVs), one of the major genomic variations, are specific to cancer types, reproducible from cell to cell, and even from patient to patient. We hypothesize that CNVs at certain genomic loci are selected for and lead to metastasis. Our work shows the prospect of noninvasive CTC-based cancer diagnostics. Circulating tumor cells (CTCs) enter peripheral blood from primary tumors and seed metastases. The genome sequencing of CTCs could offer noninvasive prognosis or even diagnosis, but has been hampered by low single-cell genome coverage of scarce CTCs. Here, we report the use of the recently developed multiple annealing and looping-based amplification cycles for whole-genome amplification of single CTCs from lung cancer patients. We observed characteristic cancer-associated single-nucleotide variations and insertions/deletions in exomes of CTCs. These mutations provided information needed for individualized therapy, such as drug resistance and phenotypic transition, but were heterogeneous from cell to cell. In contrast, every CTC from an individual patient, regardless of the cancer subtypes, exhibited reproducible copy number variation (CNV) patterns, similar to those of the metastatic tumor of the same patient. Interestingly, different patients with the same lung cancer adenocarcinoma (ADC) shared similar CNV patterns in their CTCs. Even more interestingly, patients of small-cell lung cancer have CNV patterns distinctly different from those of ADC patients. Our finding suggests that CNVs at certain genomic loci are selected for the metastasis of cancer. The reproducibility of cancer-specific CNVs offers potential for CTC-based cancer diagnostics.

Morbidity and Mortality of Laparoscopic Versus Open D2 Distal Gastrectomy for Advanced Gastric Cancer: A Randomized Controlled Trial

PURPOSE The safety and efficacy of radical laparoscopic distal gastrectomy (LG) with D2 lymphadenectomy for the treatment of advanced gastric cancer (AGC) remain controversial. We conducted a randomized controlled trial to compare laparoscopic and conventional open distal gastrectomy with D2 lymph node dissections for AGC. PATIENTS AND METHODS Between September 2012 and December 2014, 1,056 patients with clinical stage T2-4aN0-3M0 gastric cancer were eligible for inclusion. They were randomly assigned to either the LG with D2 lymphadenectomy group (n = 528) or the open gastrectomy (OG) with D2 lymphadenectomy group (n = 528). Fifteen experienced surgeons from 14 institutions in China participated in the study. The morbidity and mortality within 30 days after surgery between the LG (n = 519) and the OG (n = 520) groups were compared on the basis of the modified intention-to-treat principle. Postoperative complications were stratified according to the Clavien-Dindo classification. RESULTS The compliance rates of D2 lymphadenectomy were similar between the LG and OG groups (99.4% v 99.6%; P = .845). The postoperative morbidity was 15.2% in the LG group and 12.9% in OG group with no significant difference (difference, 2.3%; 95% CI, -1.9 to 6.6; P = .285). The mortality rate was 0.4% for the LG group and zero for the OG group (difference, 0.4%; 95% CI, -0.4 to 1.4; P = .249). The distribution of severity was similar between the two groups (P = .314). CONCLUSION Experienced surgeons can safely perform LG with D2 lymphadenectomy for AGC.

microRNAs and ceRNAs: RNA networks in pathogenesis of cancer

microRNAs (miRNAs) are a class of endogenous, single-stranded non-coding RNAs of 20-23 nucleotides in length, functioning as negative regulators of gene expression at the post-transcriptional level. The dysregulation of miRNAs has been demonstrated to play critical roles in tumorigenesis, either through inhibiting tumor suppressor genes or activating oncogenes inappropriately. Besides their promising clinical applications in cancer diagnosis and treatment, recent studies have uncovered that miRNAs could act as a regulatory language, through which messenger RNAs, transcribed pseudogenes, and long noncoding RNAs crosstalk with each other and form a novel regulatory network. RNA transcripts involved in this network have been termed as competing endogenous RNAs (ceRNAs), since they influence each others level by competing for the same pool of miRNAs through miRNA response elements (MREs) on their target transcripts. The discovery of miRNA-ceRNA network not only provides the possibility of an additional level of post-transcriptional regulation, but also dictates a reassessment of the existing regulatory pathways involved in cancer initiation and progression.

D2 dissection in laparoscopic and open gastrectomy for gastric cancer.

AIM To evaluate the radicalness and safety of laparoscopic D2 dissection for gastric cancer. METHODS Clinicopathological data from 209 patients with gastric cancer, who underwent radical gastrectomy with D2 dissection between January 2007 and February 2011, were analyzed retrospectively. Among these patients, 131 patients underwent laparoscopy-assisted gastrectomy (LAG) and 78 underwent open gastrectomy (OG). The parameters analyzed included operative time, blood loss, blood transfusion, morbidity, mortality, the number of harvested lymph nodes (HLNs), and pathological stage. RESULTS There were no significant differences in sex, age, types of radical resection [radical proximal gastrectomy (PG + D2), radical distal gastrectomy (DG + D2) and radical total gastrectomy (TG + D2)], and stages between the LAG and OG groups (P > 0.05). Among the two groups, 127 cases (96.9%) and 76 cases (97.4%) had 15 or more HLNs, respectively. The average number of HLNs was 26.1 ± 11.4 in the LAG group and 24.2 ± 9.3 in the OG group (P = 0.233). In the same type of radical resection, there were no significant differences in the number of HLNs between the two groups (PG + D2: 21.7 ± 7.5 vs. 22.4 ± 9.3; DG + D2: 25.7 ± 11.0 vs. 22.3 ± 7.9; TG + D2: 30.9 ± 13.4 vs. 29.3 ± 10.4; P > 0.05 for all comparisons). Tumor free margins were obtained in all cases. Compared with OG group, the LAG group had significantly less blood loss, but a longer operation time (P < 0.001). The morbidity of the LAG group was 9.9%, which was not significantly different from the OG group (7.7%) (P = 0.587). The mortality was zero in both groups. CONCLUSION Laparoscopic D2 dissection is equivalent to OG in the number of HLNs, regardless of tumor location. Thus, this procedure can achieve the same radicalness as OG.

Validation of the Memorial Sloan-Kettering Cancer Center Nomogram to Predict Disease-Specific Survival after R0 Resection in a Chinese Gastric Cancer Population

Background Prediction of disease-specific survival (DSS) for individual patient with gastric cancer after R0 resection remains a clinical concern. Since the clinicopathologic characteristics of gastric cancer vary widely between China and western countries, this study is to evaluate a nomogram from Memorial Sloan-Kettering Cancer Center (MSKCC) for predicting the probability of DSS in patients with gastric cancer from a Chinese cohort. Methods From 1998 to 2007, clinical data of 979 patients with gastric cancer who underwent R0 resection were retrospectively collected from Peking University Cancer Hospital & Institute and used for external validation. The performance of the MSKCC nomogram in our population was assessed using concordance index (C-index) and calibration plot. Results The C-index for the MSKCC predictive nomogram was 0.74 in the Chinese cohort, compared with 0.69 for American Joint Committee on Cancer (AJCC) staging system (P<0.0001). This suggests that the discriminating value of MSKCC nomogram is superior to AJCC staging system for prognostic prediction in the Chinese population. Calibration plots showed that the actual survival of Chinese patients corresponded closely to the MSKCC nonogram-predicted survival probabilities. Moreover, MSKCC nomogram predictions demonstrated the heterogeneity of survival in stage IIA/IIB/IIIA/IIIB disease of the Chinese patients. Conclusion In this study, we externally validated MSKCC nomogram for predicting the probability of 5- and 9-year DSS after R0 resection for gastric cancer in a Chinese population. The MSKCC nomogram performed well with good discrimination and calibration. The MSKCC nomogram improved individualized predictions of survival, and may assist Chinese clinicians and patients in individual follow-up scheduling, and decision making with regard to various treatment options.

Massive gastrointestinal bleeding caused by a giant gastric inflammatory fibroid polyp: A case report.

INTRODUCTION Inflammatory fibroid polyps (IFPs) are rare and small benign lesions throughout the digestive tract. The most common location is gastric antrum, but rarely at the upper part. Clinical manifestations of IFPs usually include intestinal obstruction, intussusception, abdominal pain, nausea and vomiting, but rare massive digestive tract hemorrhage. PRESENTATION OF CASE We describe a rare case presenting with massive gastrointestinal bleeding due to a huge gastric fundus IFP (11 cm). Finally, the patient was treated successfully by the laparoscopic assisted partial gastrectomy (LAPG) and recovered uneventfully. To our knowledge, this is the first reported case presenting with massive alimentary tract hemorrhage due to giant gastric fundus IFP. DISCUSSION Giant IFP rarely originates in the gastric fundus, but occasionally results in serious consequence, such as massive gastrointestinal bleeding. It is important to recognize IFP because it responds favorably to operation with no relapse or metastasis. CONCLUSION In the differential diagnosis of alimentary hemorrhage of uncertain etiology, gastric IFP should be considered. For huge gastric IFP, laparoscopic therapy is an apt choice.

GOLPH3 predicts survival of colorectal cancer patients treated with 5-fluorouracil-based adjuvant chemotherapy

BackgroundGolgi phosphoprotein 3 (GOLPH3) has been validated as a potent oncogene involved in the progression of many types of solid tumors, and its overexpression is associated with poor clinical outcome in many cancers. However, it is still unknown the association of GOLPH3 expression with the prognosis of colorectal cancer (CRC) patients who received 5-fluorouracil (5-FU)-based adjuvant chemotherapy.MethodsThe expression of GOLPH3 was determined by qRT-PCR and immunohistochemistry in colorectal tissues from CRC patients treated with 5-FU based adjuvant chemotherapy after surgery. The association of GOLPH3 with clinicopathologic features and prognosis was analysed. The effects of GOLPH3 on 5-FU sensitivity were examined in CRC cell lines.ResultsGOLPH3 expression was elevated in CRC tissues compared with matched adjacent noncancerous tissues. Kaplan-Meier survival curves indicated that high GOLPH3 expression was significantly associated with prolonged disease-free survival (DFS, P = 0.002) and overall survival (OS, P = 0.011) in patients who received 5-FU-based adjuvant chemotherapy. Moreover, multivariate analysis showed that GOLPH3 expression was an independent prognostic factor for DFS in CRC patients treated with 5-FU-based chemotherapy (HR, 0.468; 95%CI, 0.222-0.987; P = 0.046). In vitro, overexpression of GOLPH3 facilitated the 5-FU chemosensitivity in CRC cells; while siRNA-mediated knockdown of GOLPH3 reduced the sensitivity of CRC cells to 5-FU-induced apoptosis.ConclusionsOur results suggest that GOLPH3 is associated with prognosis in CRC patients treated with postoperative 5-FU-based adjuvant chemotherapy, and may serve as a potential indicator to predict 5-FU chemosensitivity.

Downregulated USP3 mRNA functions as a competitive endogenous RNA of SMAD4 by sponging miR-224 and promotes metastasis in colorectal cancer

Increasing evidence shows that competitive endogenous RNAs (ceRNAs) can affect the expression of other transcripts by sequestering common microRNAs (miRNAs), and participate in tumourigenesis. As a potent tumour suppressor in colorectal cancer (CRC), SMAD4 is regulated by many miRNAs. However, the regulation of SMAD4 by ceRNAs has never been examined. In the present study, we found that USP3 modulated SMAD4 expression in a miRNA dependent, and protein-coding gene independent manner. USP3 and SMAD4 were directly targeted by miR-224, and overexpression of the USP3 3′UTR could inhibit metastasis caused by the loss of USP3. The correlation of USP3, SMAD4 and miR-224 expression was further verified in CRC specimens. Additionally, the loss of USP3 was associated with distal metastasis and a poor prognosis. Altogether, our study demonstrates USP3 as a bona fide SMAD4 ceRNA. The results from this study may provide new insights into the prevention and treatment of CRC.

Evaluation of immune responses of gastric cancer patients treated by laparoscopic and open gastrectomy

Laparoscopic surgery has been shown to offer more advantages than open surgery for the treatment of gastric cancer. However, the perioperative immune responses after laparoscopic surgery remain largely unexplored. Here, we analyzed the immunity of gastric cancer patients treated by laparoscopy-assisted gastrectomy (LAG) or open gastrectomy (OG) with D2 dissection. Seventy patients were randomized into LAG and OG groups. The operative details and postoperative outcomes of the two groups were compared. The immune factors were measured preoperatively as well as on the first, third, and seventh postoperative days (POD). Our results indicate that there was no significant difference between two groups in clinical characteristics. The profiles of white blood cells, neutrophils, lymphocytes, as well as the lymphocyte subpopulations, including T lymphocytes, B lymphocytes, CD4+ T cells, and CD8+ T cells were similar in the LAG and the OG groups. Only the natural killer cell counts were significantly higher in LAG-treated patients than in OG-treated ones on POD7. Moreover, no statistical differences were found between the two groups with respect to the levels of perioperative cytokines, including IFN-γ, IL-4, IL-6, and TNF-α. However, compared with the OG group, most of the immune factors in the LAG group had trends to return to preoperative levels on POD7. Our study demonstrates that the immune function of LAG-treated patients showed patterns similar to that of OG-treated patients, although larger prospective multicenter trials are needed to further evaluate the immunological status of LAG.

Whole exome sequencing reveals intertumor heterogeneity and distinct genetic origins of sporadic synchronous colorectal cancer

Sporadic synchronous colorectal cancer (CRC) refers to more than one primary tumor detected in a single patient at the time of the first diagnosis without predisposition of cancer development. Given the same genetic and microenvironment they raise, sporadic synchronous CRC is a unique model to study CRC tumorigenesis. We performed whole exome sequencing in 32 fresh frozen tumor lesions from 15 patients with sporadic synchronous CRC to compare their genetic alterations. This approach identified ubiquitously mutated genes in the range from 0.34% to 4.22% and from 0.8% to 7.0% in non‐hypermutated tumors and hypermutated tumors, respectively, in a single patient. We show that both ubiquitously mutated genes and candidate cancer genes from different tumors in the same patient mutated at different sites. Consistently, obvious differences in somatic copy number variations (SCNV) were found in most patients with non‐hypermutated tumor lesions, which had ubiquitous copy number amplification rates ranging from 0% to 8.8% and ubiquitous copy number deletion rates ranging from 0% to 8.2%. Hypermutated lesions were nearly diploid with 0% to 18.8% common copy number aberrations. Accordingly, clonal structures, altered signaling pathways and druggable genes in a single patient with synchronous CRC varied significantly. Taken together, the disparate SCNVs and mutations in synchronous CRC supported the field effect theory of tumorigenesis. Moreover, the intertumor heterogeneity of synchronous CRCs implies that analysis of all tumor lesions from the same patient is necessary for appropriate clinical treatment decisions.