Overweight/obesity-related transcriptomic signature as a correlate of clinical outcome, immune microenvironment, and treatment response in hepatocellular carcinoma

BACKGROUNDS

The pandemic of overweight and obesity (quantified by body mass index (BMI) ≥ 25) has rapidly raised the patient number of non-alcoholic fatty hepatocellular carcinoma (HCC), and several clinical trials have shown that BMI is associated with the prognosis of HCC. However, whether overweight/obesity is an independent prognostic factor is arguable, and the role of overweight/obesity-related metabolisms in the progression of HCC is scarcely known.

MATERIALS AND METHODS

In the present study, clinical information, mRNA expression profile, and genomic data were downloaded from The Cancer Genome Atlas (TCGA) as a training cohort (TCGA-HCC) for the identification of overweight/obesity-related transcriptome. Machine learning and the Cox regression analysis were conducted for the construction of the overweight/obesity-associated gene (OAG) signature. The Kaplan-Meier curve, receiver operating characteristic (ROC) curve, and the Cox regression analysis were performed to assess the prognostic value of the OAG signature, which was further validated in two independent retrospective cohorts from the International Cancer Genome Consortium (ICGC) and Gene Expression Omnibus (GEO). Subsequently, functional enrichment, genomic profiling, and tumor microenvironment (TME) evaluation were utilized to characterize biological activities associated with the OAG signature. GSE109211 and GSE104580 were retrieved to evaluate the underlying response of sorafenib and transcatheter arterial chemoembolization (TACE) treatment, respectively. The Genomics of Drug Sensitivity in Cancer (GDSC) database was employed for the evaluation of chemotherapeutic response.

RESULTS

Overweight/obesity-associated transcriptome was mainly involved in metabolic processes and noticeably and markedly correlated with prognosis and TME of HCC. Afterward, a novel established OAG signature (including 17 genes, namely, GAGE2D, PDE6A, GABRR1, DCAF8L1, DPYSL4, SLC6A3, MMP3, RIBC2, KCNH2, HTRA3, PDX1, ATHL1, PRTG, SHC4, C21orf29, SMIM32, and C1orf133) divided patients into high and low OAG score groups with distinct prognosis (median overall survival (OS): 24.87 vs. 83.51 months, p < 0.0001), and the values of area under ROC curve (AUC) in predicting 1-, 2-, 3-, and 4-year OS were 0.81, 0.80, 0.83, and 0.85, respectively. Moreover, the OAG score was independent of clinical features and also exhibited a good ability for prognosis prediction in the ICGC-LIHC-JP cohort and GSE54236 dataset. Expectedly, the OAG score was also highly correlated with metabolic processes, especially oxidative-related signaling pathways. Furthermore, abundant enrichment of chemokines, receptors, MHC molecules, and other immunomodulators as well as PD-L1/PD-1 expression among patients with high OAG scores indicated that they might have better responses to immunotherapy. However, probably exclusion of T cells from infiltrating tumors resulting in lower infiltration of effective T cells would restrict immunotherapeutic effects. In addition, the OAG score was significantly associated with the response of sorafenib and TACE treatment.

CONCLUSIONS

Overall, this study comprehensively disclosed the relationship between BMI-guided transcriptome and HCC. Moreover, the OAG signature had the potential clinical applications in the future to promote clinical management and precision medicine of HCC.

Role of RNA-interference-induced zinc finger protein 139 suppression in gastric cancer cell sensitivity to chemotherapeutic agents

Zinc finger proteins (ZNFs) are a class of proteins widely distributed in the human genome, which have been found to play a role in the regulation of gene transcription and the occurrence and development of gastric cancer (GC). ZNF139 was found to be associated with GC in our previous experiments. The present study aimed to analyse the differences in ZNF139 protein expression in SGC7901 GC cells and in situ grafted GC tumors in nude mice prior to and following RNA interference inhibition, and to investigate the mechanisms underlying ZNF139 involvement in the occurrence, development and chemosensitivity of GC. A ZNF139-targeted small interfering (si)RNA plasmid was constructed and transfected into the cancer cells and in situ grafted tumors. The MTT assay was used to investigate the alterations in chemosensitivity prior to and following transfection of siRNA-ZNF139. The two-dimensional difference gel electrophoresis and liquid chromatography-mass spectrometry techniques were used to identify the different protein points prior to and following siRNA-ZNF139 transfection. Western blot analysis was performed to confirm the identified proteins. In the siRNA-ZNF139 group, the growth of the cancer cells and in situ grafted tumors significantly decreased. However, the post-interference chemosensitivity to 5-fluorouracil, cisplatin and mitomycin C significantly increased. In the in vivo and in vitro experiments, the expression of pyridoxal kinase (PDXK) was upregulated, whereas the expression levels of annexin A2 (ANXA2) and fascin were downregulated following transfection. Western blot analysis confirmed the results for PDXK, ANXA2 and fascin by proteomics. Therefore, ZNF139 may participate in the occurrence, development and chemosensitivity of GC by promoting the expression of ANXA2 and fascin, while inhibiting the expression of PDXK.

[Effect and mechanisms of TET on human gastric carcinoma cell line SGC7901 and SGC7901/ADR]

OBJECTIVE

To investigate the effect of tetrandrine (TET) on zinc finger protein 139 (ZNF139) and multidrug resistance (MDR) of human gastric carcinoma cell lines and possible mechanisms.

METHODS

Cultured SGC7901 and SGC7901/ADR were treated with TET (0.5, 1.0, 1.5, 2.0, and 2.5 microg/mL), then inhibition rates were measured by MTT assay in vitro. The expressions of ZNF139, MRP-1, MDR1, and GST-pi were detected by RT-PCR. The correlation between ZNF139 and each multidrug resistance factor was analyzed using Spearman correlation analysis, and the coefficient correlation was calculated.

RESULTS

The inhibition rate of TET (< or = 2.0 microg/mL) for SGC7901 and SGC7901/ADR was less than 10% with MTT assay. Expressions of ZNF139, MRP-1, MDR1, and GST-pi mRNA were higher in SGC7901/ADR than in SGC7901 (all P < 0.05). The expressions of ZNF139, MRP-1, MDR1, and GST--pi were down-regulated in SGC7901/ADR cells efficiently (all P < 0.01). Positive correlation existed between ZNF139 and MRP-1, ZNF139 and MDR1 before treated by TET in SGC7901/ADR, and this relationship also existed in SGC7901/ADR cells after treated by TET (all P < 0.05).

CONCLUSION

TET could achieve MDR reversion in gastric cancer cells by down-regulating the expression of ZNF139, MRP-1, and MDR1.

Histological complete response after neoadjuvant XELOX in advanced gastric carcinoma

We report on a case of a 65-year-old Chinese male with locally advanced gastric adenocarcinoma achieving pathological complete response after neoadjuvant chemotherapy with capecitabine and oxaliplatin (XELOX) regimen. He underwent esophagogastroduodenoscopy, which revealed a 6x5cm gastric ulcer. Biopsy of gastric ulcer revealed adenocarcinoma. Further workups with abdominal enhancement computed tomography (CT) staged his cancer as T4N2M0. He received 2 cycles of neoadjuvant chemotherapy with XELOX without severe toxicity. Afterwards, he underwent curative surgery consisting of total gastrectomy with extended D2 lymph node dissections and a Roux-en-Y esophagojejunostomy. On microscopic examination, no tumor cells were detected in the ulcer scar of the resected stomach and in the regional lymph nodes. The benefit of XELOX regimen as neoadjuvant chemotherapy in gastric cancer is worth further investigation.

[Detecting bone marrow micrometastasis of gastric cancer by magnetic activated cell sorting combined with fluorescent activated cell sorting]

BACKGROUND & OBJECTIVE

Several methods are used to detect bone marrow micrometastasis of gastric cancer with different accuracies. In breast cancer, tumor cells in blood can be detected sensitively and specifically by magnetic activated cell sorting (MACS) and fluorescent activated cell sorting (FACS). This study was to investigate the clinical value of this method in detecting bone marrow micrometastasis of gastric cancer.

METHODS

Thirty-five patients, who received operation for gastric cancer from Dec. 2002 to Jun. 2003, were selected. Mononuclear cells were separated from their bone marrows. After marked by MACS minibeads conjugated with cytokeratin (CK) 7/8 antibodies, anti-CK-fluorescein isothiocyanate (FITC), and anti-CD45-perdinin chlorophyll protein (PerCP), tumor cells were enriched twice by MS+/RS+ positive separation column. FACS analysis was conducted on these samples before and after MACS enrichment. The results were compared with clinicopathologic parameters.

RESULTS

Disseminated tumor cells were detected in bone marrow of 3 samples(8.6%) before MACS enrichment, and 25 samples (71.4%) after enrichment. The frequencies of tumor cells were 1.4 x 10(-8)-2.4 x 10(-5), 2.2 x 10(-7) -3.7 x 10(-5), and 4.0 x 10-(6)-8.6 x 10(-5) in patients with moderately differentiated, poorly differentiated, and undifferentiated carcinoma, respectively, with significant differences (P = 0.026). Bone marrow micrometastasis positively correlated with tumor TNM stage (P = 0.008), while had no correlation with tumor size, depth of wall invasion, and other clinicopathologic parameters.

CONCLUSIONS

MACS combined with FACS may improve detection rate of bone marrow micrometastasis of gastric cancer. The patients with poor differentiation and in advanced TNM stage have more disseminated tumor cells in bone marrow.

[Expression of MUC1, CD44v6, nm23 in gastric carcinomas and regional lymph node tissues and their association with invasion, metastasis, and prognosis of the tumor]

BACKGROUND & OBJECTIVE

The invasion depth and lymph node metastasis result from the polygenes and their protein expression in gastric carcinoma. The key of the basic and clinical research of the gastric carcinoma is to find out the related molecular biology marker. This study was designed to investigate the relationship between the expression of MUC1, CD44v6, nm23 in gastric carcinomas and regional lymph node tissues and invasion, metastasis, and prognosis of the tumor.

METHODS

The expression of MUC1, CD44v6, and nm23 in 110 advanced gastric carcinomas and 613 regional lymph node specimens were examined by immunohistochemical technique. The results was judged by the criterion of the positive or the negative expression.

RESULTS

(1) The expression of MUC1 (84.6%, 88.1%, 87.3%, 91.7%, 94.4%, and 95.5%, respectively) and CD44v6 (79.5%, 74.6%, 79.4%, 81.7%, 87.0%, and 87.9%, respectively) in gastric carcinoma tissues in the groups of low differentiated adenocarcinoma, infiltrated type, T3+T4, lymph node metastasis, stage III-IV, and survival < 5 years were significantly higher than those in the groups of high-middle differentiated adenocarcinoma, limited type, T1+T2, no lymph node metastasis, stage I-II, and survival >or= 5 years (P< 0.01 or P< 0.05); while the expression of nm23 was contrary (P< 0.01 or P< 0.05) except for the groups of differentiation and Borrmann type. (2) The expression of MUC1 and CD44v6 in the lymph node metastasis group of the gastric carcinoma (94.7% and 89.4%, respectively)were remarkably higher than those in the no lymph node metastasis group (19.6% and 19.6%, respectively) (P< 0.01); while the expression of nm23 was contrary (16.8% versus 74.9%, P< 0.01). (3) The 5-year survival rates of the patients in MUC1 and CD44v6 positive expression group (13.0% and 15.4%, respectively) in the regional lymph nodes of gastric carcinoma were significantly lower than those in the negative expression group (100% and 62.1%) (P< 0.01); while the 5-year survival rate of the patients in nm23 positive expression group was contrary (70.0% versus 4.0%, P< 0.01).

CONCLUSION

The high expression of MUC1, CD44v6 and low expression of nm23 were related to the invasion, metastasis, and prognosis of the gastric carcinoma. The detection of MUC1, CD44v6, and nm23 can be useful for the diagnosis and treatment of advanced gastric carcinoma.