Transcription factor FOXP4 inversely governs tumor suppressor genes and contributes to thyroid cancer progression

Objective

In recent decades, thyroid cancer (TC) has exhibited a rising incidence pattern. Elevated levels of the transcription factor FOXP4 have been strongly linked to the progression of diverse tumors; nevertheless, its specific role in thyroid cancer remains underexplored. The primary objective of this study was to elucidate the functions of FOXP4 and its associated target gene, FBXW7, in the context of thyroid cancer.

Methods

FOXP4 and FBXW7 expression levels in TC tissues and cell lines were assessed through immunohistochemistry and RT-qPCR analyses. The functional aspects of FOXP4, including its effects on cell proliferation, migration capabilities, cell cycle regulation, and epithelial-mesenchymal transition (EMT), were investigated. Furthermore, the interaction between FOXP4 and FBXW7 was confirmed using chromatin immunoprecipitation (ChIP) assays. The impact of FBXW7 on FOXP4-mediated cellular phenotypes was subsequently examined. Additionally, the in vivo role of FOXP4 and FBXW7 in tumor growth was elucidated through the establishment of a murine tumor model.

Results

Elevated levels of FOXP4 were observed in papillary carcinoma tissues, and patients exhibiting high FBXW7 levels showed a more favorable prognosis. KTC-1 cells displayed a concomitant increase in FOXP4 expression and decrease in FBXW7 expression. FOXP4 overexpression in these cells enhanced cell proliferation, migration capabilities, and EMT. The interaction between the FOXP4 protein and the FBXW7 promoter was confirmed, and the effects of FOXP4 were mitigated upon overexpression of FBXW7. Furthermore, knockdown of FOXP4 led to decelerated growth of transplanted tumors and increased FBXW7 levels within the tumors.

Conclusion

The findings of the current study underscore the regulatory role of FOXP4 in the transcription of FBXW7 and establish a clear link between aberrations in FBXW7 expression and the manifestation of malignant phenotypes in highly aggressive TC cells.

The essential role of forkhead box P4 (FOXP4) in thyroid cancer: a study related to The Cancer Genome Atlas and experimental data

OBJECTIVE

Thyroid cancer (THCA) is the most common endocrine cancer in the world. Although most patients with THCA have a good prognosis, the prognosis of those with THCA who have an extra-glandular invasion, vascular invasion, and distant metastasis is poor. Therefore, it is very important to find potential biomarkers that can effectively predict the prognosis and progression of highly aggressive THCAs. It has been identified that forkhead box P4 (FOXP4) may be a new biomarker for the proliferation and prognosis for tumor diagnosis. However, the expression and function of FOXP4 in THCA remain to be determined.

METHODS

In the present study, the function of FOXP4 in cells was investigated through the comprehensive analysis of data in The Cancer Genome Atlas and combined with experiments including immunohistochemistry (IHC), colony formation, Cell Counting Kit-8 assay, wound scratch healing, and transwell invasion assay.

RESULTS

In the present study, relevant bioinformatic data showed that FOXP4 was highly expressed in THCA, which was consistent with the results of the IHC and cell experiments. Meanwhile, 10 FOXP4-related hub genes were identified as potential diagnostic genes for THCA. It was found in further experiments that FOXP4 was located in the nucleus of THCA cells, and the expression of FOXP4 in the nucleus was higher than that in the cytoplasm. FOXP4 knockdown inhibited in vitro proliferation of the THCA cells, whereas overexpression promoted the proliferation and migration of THCA cells. Furthermore, deficiency of FOXP4 induced cell-cycle arrest.

CONCLUSION

FOXP4 might be a potential target for diagnosing and treating THCA.

FOXP4-AS1 Inhibits Papillary Thyroid Carcinoma Proliferation and Migration Through the AKT Signaling Pathway

Papillary thyroid carcinoma, also known as PTC, is one of the commonest malignancies in the endocrine system. Long non-coding RNAs (lncRNAs) in PTC could maintain proliferative signaling, induce therapeutic resistance, activate invasion and migration, and sustain stem cell-like characteristics. In this paper, results showed that lncRNA forkhead box P4 antisense RNA 1 (FOXP4-AS1) is downregulated in PTC tissues and cell lines. Patients in TCGA cohort with a higher FOXP4-AS1 expression showed a higher disease-free interval (DFI) rate, and the expression of FOXP4-AS1 is shown to be linked to the clinical stage, T stage, N stage, and extraglandular invasion condition of the TC patients. FOXP4-AS1 is localized in the cell cytoplasmic domain of PTC cells. Functionally, upregulated FOXP4-AS1 inhibited PTC cell proliferation, apoptosis, and migration, whereas it downregulated FOXP4-AS1-promoted progression of PTC. In vivo assay also confirmed the tumor inhibitory effect of FOXP4-AS1 in PTC growth. Mechanism analysis indicated that FOXP4-AS1 can play its functions by regulating the AKT signaling pathway, and AKT inhibitor treatment could attenuate the impact of FOXP4-AS1 on PTC progression. Furthermore, FOXP4-AS1 also negatively regulates the expression of its host gene FOXP4. Collectively, we showed that FOXP4-AS1 inhibited PTC progression although AKT signaling and FOXP4-AS1 plays a tumor-suppressor role in PTC tumorigenesis.

Exploring the underlying molecular mechanism of liver cancer cells under hypoxia based on RNA sequencing

Background

The aim of our study was to use the differentially expressed mRNAs (DEmRNAs) and differentially expressed miRNAs (DEmiRNAs) to illustrate the underlying mechanism of hypoxia in liver cancer.

Methods

In this study, a cell model of hypoxia was established, and autophagy activity was measured with western blotting and transmission electron microscopy. The effect of hypoxia conditions on the invasion of liver cancer cell was evaluated. RNA sequencing was used to identify DEmRNAs and DEmiRNAs to explore the mechanism of hypoxia in liver cancer cells.

Results

We found that autophagy activation was triggered by hypoxia stress and hypoxia might promote liver cancer cell invasion. In addition, a total of 407 shared DEmRNAs and 57 shared DEmiRNAs were identified in both HCCLM3 hypoxia group and SMMC-7721 hypoxia group compared with control group. Furthermore, 278 DEmRNAs and 24 DEmiRNAs were identified as cancer hypoxia-specific DEmRNAs and DEmiRNAs. Finally, we obtained 19 DEmiRNAs with high degree based on the DEmiRNA-DEmRNA interaction network. Among them, hsa-miR-483-5p, hsa-miR-4739, hsa-miR-214-3p and hsa-miR-296-5p may be potential gene signatures related to liver cancer hypoxia.

Conclusions

Our study may help to understand the potential molecular mechanism of hypoxia in liver cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12863-022-01055-9.

Inhibition of circular RNA_0000285 prevents cell proliferation and induces apoptosis in thyroid cancer by sponging microRNA-654-3p

Thyroid cancer is derived from follicular or thyroid cells and has become the most prevalent malignant tumor of endocrine organs, with increased morbidity and mortality. Circular RNAs (circRNAs) are used as prognostic and predictive markers for different types of cancer. However, the role of circRNA_0000285 in thyroid cancer and its potential molecular mechanism remain unclear. The present study aimed to investigate the roles and underlying molecular mechanism of circRNA_0000285 in thyroid cancer to identify novel treatments for this disease. The target binding site of circRNA_0000285 and microRNA-654-3p (miR-654-3p) were predicted and confirmed via the dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Thyroid cancer cell viability and apoptosis were determined via the MTT assay and flow cytometric analysis, respectively, whereas the expression levels of circRNA_0000285 and miR-654-3p were determined via reverse transcription-quantitative PCR analysis. In addition, the protein expression levels of the apoptosis-associated proteins, Bax and B-cell lymphoma 2 (Bcl-2), were detected via western blotting. The results of the dual-luciferase reporter and RIP assays demonstrated that miR-654-3p directly targeted circRNA_0000285. The expression levels of circRNA_0000285 and miR-654-3p in thyroid cancer cells (TPC-1 and FTC133) were upregulated and downregulated, respectively. Knockdown of circRNA_0000285 via small interfering (si)RNA inhibited circRNA_0000285 levels and increased miR-654-3p levels. In addition, miR-654-3p expression decreased following transfection with miR-654-3p inhibitor. Functional experiments demonstrated that circRNA_0000285-siRNA decreased thyroid cancer cell proliferation, promoted cell apoptosis, enhanced Bax expression and suppressed Bcl-2 expression. All these effects were reversed following transfection with miR-654-3p inhibitor. Taken together, the results of the present study suggest that circRNA_0000285 plays a vital role in thyroid cancer progression by regulating miR-654-3p, which provides a potential therapeutic target for this disease.

Uncovering the potential differentially expressed miRNAs as diagnostic biomarkers for hepatocellular carcinoma based on machine learning in The Cancer Genome Atlas database

The present study aimed to identify novel diagnostic differentially expressed microRNAs (miRNAs/miRs) in order to understand the molecular mechanisms underlying hepatocellular carcinoma. The expression data of miRNA and mRNA were downloaded for differential expression analysis. Optimal diagnostic differentially expressed miRNA biomarkers were identified via a random forest algorithm. Classification models were established to distinguish patients with hepatocellular carcinoma and normal individuals. A regulatory network between optimal diagnostic differentially expressed miRNA and differentially expressed mRNAs was then constructed. The GSE63046 dataset and in vitro experiments were used to validate the expression of the optimal diagnostic differentially expressed miRNAs identified. In addition, diagnostic and prognostic analyses of optimal diagnostic differentially expressed miRNAs were performed. In total, 14 differentially expressed miRNAs (all upregulated) and 2,982 differentially expressed mRNAs (1,989 upregulated and 993 downregulated) were identified. hsa-miR-10b-5p, hsa-miR-10b-3p, hsa-miR-224-5p, hsa-miR-183-5p and hsa-miR-182-5p were considered as the optimal diagnostic biomarkers for hepatocellular carcinoma. The mRNAs targeted by these five miRNAs included secreted frizzled related protein 1 (SFRP1), endothelin receptor type B (EDNRB), nuclear receptor subfamily 4 group A member 3 (NR4A3), four and a half LIM domains 2 (FHL2), NK3 homeobox 1 (NKX3-1), interleukin 6 signal transducer (IL6ST) and forkhead box O1 (FOXO1). ‘Bile acid biosynthesis and cholesterol’ was the most enriched signaling pathways of these target mRNAs. The expression validation of the five miRNAs was consistent with the present bioinformatics analysis. Notably, hsa-miR-10b-5p and hsa-miR-10b-3p had a significant prognosis value for patients with hepatocellular carcinoma. In conclusion, the five differentially expressed miRNAs may be considered as diagnostic biomarkers for patients with hepatocellular carcinoma. In addition, the differential expression levels of the targets of these five mRNAs, including SFRP1, EDNRB, NR4A3, FHL2, NKX3−1, IL6ST and FOXO1, may be involved in hepatocellular carcinoma tumorigenesis.

Investigation Of Small Molecular Substances As Potential Biomarkers For Discrimination Of Gastric Tumor

Background

Gastric tumor (GT) is associated with high morbidity and mortality, with surgery among the most effective treatment methods. Accurate interoperative determination of the tumor margin is crucial.

Methods

In this study, using internal extractive electrospray ionization-MS, mass spectral data of GT and gastric normal (GN) tissues from 36 patients were collected.

Results

In positive ion detection mode, the relative abundances of m/z 132, 147, 170, and 175 were increased, while the relative abundances of m/z 55, 83, 154, and 203 were decreased in GT tissue. Using partial least squares analysis, the mass spectral data of GT and GN tissues were discriminated, and differential ions (P≤0.01), including m/z 55, 83, 154, 170, and 203, were obtained from loading plots. After receiver operating characteristic curve analysis, peaks at m/z 83 and 203 showed high accuracy for distinguishing GT from GN tissue. These two peaks were then preliminarily attributed to 5-aminoimidazole and serylproline, respectively, which might be useful molecular biomarkers associated with GT development.

Conclusion

Further investigations of the functions of 5-aminoimidazole and serylproline might provide a better understanding of the underlying mechanisms involved in GT.

Characterization and evolution of intestine injury at the anhepatic phase in portal hypertensive rats

The aim of the present study was to investigate the characteristics and progression of intestinal injury at the anhepatic phase in portal hypertensive rats. A total of 120 healthy male Wistar rats were purchased, with 15 rats in the normal control group and 105 rats were assigned to establish a prehepatic portal hypertension model. The 105 model rats were further divided into seven treatment groups following ischemia-reperfusion. Meanwhile, portal vein pressure, the area of lower esophageal mucosal vein, endotoxin levels in portal vein blood and the level of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured. Morphology changes of the intestine were observed using optical microscopy and transmission electron microscopy. A portal hypertension rat model was successfully established. Furthermore, endotoxin, MDA and SOD level reached a peak at 12-24 h following reperfusion and then decreased gradually to normal levels at 1 week following reperfusion. However, cytological damage did not recover to preoperative level within 1 week. These findings suggest that intestinal injury was most severe within 12-24 h following ischemia-reperfusion and most indicators recovered to almost normal levels. Therefore, further study on the intestinal mucosal damage is required, with the aim to reduce the production of intestinal endotoxin.

Multiple Frequency Bands Analysis of Large Scale Intrinsic Brain Networks and Its Application in Schizotypal Personality Disorder

The human brain is a complex system composed by several large scale intrinsic networks with distinct functions. The low frequency oscillation (LFO) signal of blood oxygen level dependent (BOLD), measured through resting-state fMRI, reflects the spontaneous neural activity of these networks. We propose to characterize these networks by applying the multiple frequency bands analysis (MFBA) to the LFO time courses (TCs) resulted from the group independent component analysis (ICA). Specifically, seven networks, including the default model network (DMN), dorsal attention network (DAN), control executive network (CEN), salience network, sensorimotor network, visual network and limbic network, are identified. After the power spectral density (PSD) analysis, the amplitude of low frequency fluctuation (ALFF) and the fractional amplitude of low frequency fluctuation (fALFF) is determined in three bands: <0.1 Hz; slow-5; and slow-4. Moreover, the MFBA method is applied to reveal the frequency-dependent alternations of fALFF for seven networks in schizotypal personality disorder (SPD). It is found that seven networks can be divided into three categories: the advanced cognitive networks, primary sensorimotor networks and limbic networks, and their fALFF successively decreases in both slow-4 and slow-5 bands. Comparing to normal control group, the fALFF of DMN, DAN and CEN in SPD tends to be higher in slow-5 band, but lower in slow-4. Higher fALFF of sensorimotor and visual networks in slow-5, higher fALFF of limbic network in both bands have been observed for SPD group. The results of ALFF are consistent with those of fALFF. The proposed MFBA method may help distinguish networks or oscillators in the human brain, reveal subtle alternations of networks through locating their dominant frequency band, and present potential to interpret the neuropathology disruptions.

Association of microRNA-related gene XPO5 rs11077 polymorphism with susceptibility to thyroid cancer

Exportin 5 (XPO5) is a microRNA (miRNA)-related nuclear export protein, and its disorder may lead to the dysregulation of miRNAs. Recent studies have demonstrated that the aberrant expression of XPO5 might participate in carcinogenesis in certain cancers. However, there is only limited information of XPO5 in thyroid cancer (TC) development. In our study, we quantified the expression level of XPO5 by real-time polymerase chain reaction (PCR) in 64 TC patients' cancer tissues and adjacent normal tissues. After confirming the XPO5 expression, we evaluated the association between XPO5 potential functional single-nucleotide polymorphisms (SNPs) and risk of TC in a Chinese population (1140 cases vs 1230 controls). Finally, luciferase assays were performed to investigate the function of the SNP in XPO5 3' untranslation region. The message ribonucleic acid (RNA) levels of XPO5 were significantly lower in cancer tissues than normal tissues (P = 0.004). In SNPs screening, only 1 noble SNP rs11077 was identified in XPO5 functional region. The results in our case-control study also confirmed that XPO5 rs11077 was significantly associated with onset of TC (GT/GG vs TT P = 0.035, adjusted odds ratio = 1.25, 95% confidence interval = 1.02-1.54). The adverse influence of this polymorphism was mainly observed in age >45 years (P = 0.028), female (P = 0.020), T1 staging (P = 0.026), N1 (P = 0.038), metastasis (P = 0.031 M0, and P = 0.035 for M1), and early stage (I + II) (P = 0.021). A following luciferase test revealed the critical role of rs11077 for triggering the XPO5 expression. Furthermore, patients with G allele of rs11077 showed lower XPO5 expression level. XPO5 SNP rs11077 influences the expression of XPO5, and this SNP could also be a potential biomarker for the diagnosis of TC in clinical, especially in Chinese population.

Pulmonary injury at the anhepatic phase without veno-venous bypass in portal hypertensive rats

OBJECTIVE

In order to understand the characterization and evolution of pulmonary injury, a portal hypertension rat model was used to imitate the anhepatic phase during standard orthotopic liver transplantation without veno-venous bypass.

METHODS

In this study, 135 healthy male Wistar rats were selected; in which 15 rats were assigned in the normal control (NC) group and the remaining 120 rats were used to establish a recoverable prehepatic portal hypertension model, which were further evenly divided into eight groups after ischemia-reperfusion: portal hypertensive control group (PHTC), R0h, R6h, R12h, R24h, R48h, R72h, and R7d groups. Meanwhile, arterial blood pressure, dry-to-wet weight ratios of the lung, alanine aminotransferase (ALT) level in serum, arterial oxygen pressure (PaO₂), and myeloperoxidase (MPO) activity in lung tissue were measured. Morphology changes of the lung were observed using an optical microscope and a transmission electron microscope.

RESULTS

The portal hypertension rat model was successfully established three weeks after the first operation. These portal hypertensive rats could withstand 1 hour at the anhepatic phase. Pulmonary injury severity increased to the most at 12-24 hours, and decreased to normal at seven days after reperfusion.

CONCLUSION

Ischemia-reperfusion injury is an important mechanism that results in pulmonary injury after liver transplantation. It is safe for portal hypertensive rats to tolerate 1 hour at the anhepatic phase. Pulmonary injury was the most severe within 12-24 hours after ischemia-reperfusion.

[Review on the associations of signal transducer and activators of transcription 3 with hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) is one of the most common malignancies with high fatality rate in China. To investigate the related risk factors and therapeutic targets, and actively carry out the prevention and early treatment is of great public health value. Signal transducer and activators of transcription 3 (STAT3) is the key molecule of multiple inflammation-associated signaling pathways. Recent studies have found that HCC patients have high expressing levels of STAT3 in tumor tissues, and aberrant activation of STAT3 is closely associated with the occurrence, development, invasion, metastasis, and prognosis of HCC. In this paper, we reviewed the researches on the associations of STAT3 with the occurrence and prognosis of HCC and prospected on the issues of causal prophylaxis and targeted therapy for HCC which could offer reference for the protection strategy of HCC.

[Peripheral Th17 cell frequencies predict postoperative complications in patients with hepatitis B virus-related liver cirrhosis following liver transplantation]

OBJECTIVE

To investigate the relationship between level of Th17/CD4+T cell ratio in peripheral blood and postoperative complications in patients with hepatitis B virus (HBV)-related cirrhosis after orthotopic liver transplantation (OLT).

METHODS

Fifty-one patients with HBV-related cirrhosis who received OLT were enrolled in this study. Flow cytometry analysis was performed to measure the proportion of Th17 cells to CD4+T cells at the following time points:pre-OLT, and post-OLT days 7, 14 and 21. The relevant hepatic biochemistry indexes, serum concentration of FK506 and level of procalcitonin (PCT) were detected for all patients after OLT.

RESULTS

The transplant recipients were divided into four groups according to the postoperative complication, which included acute rejection (AR, n=12), postoperative infection (POI, n=10), transient intrahepatic cholestasis (TIHC, n=12) and no complications (n=17). The Th17/CD4+T cell frequencies were notably higher in the AR patients after OLT (vs. before OLT, P less than 0.01) and this increase was positively correlated with rejection activity index (RAI; r=0.759, P=0.004). Up to post-OLT day 14, the frequencies of Th1 7/CD4+T cells in the POI group were similar to those of the AR group but they decreased to near-baseline level at post-OLT day 21.Furthermore, the percentage of Th17/CD4+T cells in the POI group was positively correlated with PCT (r=0.768, P=0.010). The frequencies of Th17/CD4+T cells in the TIHC and no complications groups showed a slowly decreasing trend after OLT and became markedly lower than the before OLT levels (P<0.01). The concentration of FK506 in the AR group was significantly lower than that in the other groups at post-OLT day 14 (P=0.000).

CONCLUSIONS

Th17/CD4+T cell level in peripheral blood might be a useful marker for risk assessment and monitoring of OLT postoperative complications, such as acute rejection and postoperative infection, in the early stage, and might help to improve patient prognosis by allowing for timely application of anti-rejection and antibacterial agents.

[Study on the correlation between BRAF(V600E) mutation and lymphatic metastases in papillary thyroid cancer staged preoperativelv as N0]

OBJECTIVE

To study the prevalence of BRAF(V600E) mutations in small (≤ 2 cm) papillary thyroid carcinoma (PTC), explore the correlation with occult central nodal metastasis (CNM) of clinically-nodal negative (cN0) neck for small (≤ 2 cm) papillary thyroid carcinoma (PTC).

METHOD

Primary tumor tissue (paraffin-embedded) from 72 patients with small (≤ 2 cm) cN0 PTC who underwent prophylactic central neck dissection (pCND) was tested for BRAF mutation. by nested PCR, the factors of lymph node metastasis such as clinicopathologic including tumor size, multifocality, extrathyroidal invasion, and BRAF mutations were analyzed. Prediction scores were generated using logistic regression models and BRAF was evaluated to see if it was a risk factor for CNM.

RESULT

The prevalence of BRAF was 47.22% (34/72) while the rate of CNM was 36.11% (26/72). Univariate analysis showed that the risk factors of lymph node metastasis for cN0 PTC were significantly correlated with tumor size (P = 0.016), bilateral tumor (P = 0.010), multifocality (P = 0.026), extrathyroidal invasion (P = 0.024), and BRAF mutations (P = 0.041). Univariate analysis showed that tumor size (OR = 2.674, 95% CI = 1.702-3.997), multifocality (OR = 1.371, 95% CI = 1.065-2.087), extrathyroidal invasion (OR = 0.540, 95% CI = 0.396-0.794) and BRAF (OR = 1.647, 95% CI = 1.101-2.463) were risk predictors of CNM.

CONCLUSION

The incidence of central neck micrometastatic disease is 36.11% in patients with PTC deemed N0 preoperatively by clinical examination and ultrasound of the neck lymph nodes and intraoperatively by inspection of the central compartment. The factors of high risk of CNM included tumor size, multifocality, extrathyroidal invasion, BRAF mutations. When a patient has the risk factors of lymph node metastasis should be electived prophylactic CCND.

[Diagnosis value of thyroid imaging reporting and data system in thyroid nodules]

OBJECTIVE

To explore the diagnostic value of the proposed thyroid imaging reporting and data system (TI-RADS) classification in thyroid nodules, and to investigate interobserver variability among different observers using TI-RADS classification for ultrasound.

METHOD

We reviewed 667 thyroid nodules conventional ultrasound image data from 532 patients who were confirmed by Pathological diagnosis. Those ultrasound images were reviewed by 4 experienced sonographers who can independently assessed the sonographic characteristics and analyzed according to the TI-RADS classification. It is to assess the diagnostic sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the TI-RADS classification. The multirater kappa statistics were used to assess the interobserver agreement among different observers.

RESULT

The overall sensitivity, specificity, negative predictive value (NPV) and Accuracy were 94%, 79%, 97% and 81%, respectively. Positive predictive values (PPVs) for categories 4 and 5 were 55% and 92%. There was substantial interobserver agreement for categories 3, 4B and 5 (Kappa = 0.62, 95% CI, 0.58-0.65), and was moderate agreement for category 4A (Kappa = 0.57) and 4B(Kappa = 0.60).

CONCLUSION

The diagnostic criteria of TI-RADS for differentiating between benign and malignant thyroid nodules have a high diagnostic value. There was substantial interobserver agreement in different experienced sonographers. The TI-RADS diagnostic criteria have a high diagnostic value and has great practical value in making a proper and further treatment plan.

[Clinical application of carbon nanoparticles labeled lymph node in cervical lymph node dissection with papillary thyroid cancer staged preoperatively as N0]

OBJECTIVE

To investigate the clinical application of carbon nanoparticles staining in cervical lymph node dissection on clinical neck lymph nodes the negative (cN0 period) thyroid papillary thyroid carcinoma (PTC).

METHOD

This retrospective analysis comprised 100 papillary thyroid cancer patients who met inclusion criteria,and they were randomly divided into the nano-carbon group (50 cases) and control group (50 cases). They underwent lobectomy, subtotal thyroidectomy or total thyroidectomies and were given elective central compartment neck dissection (CCND). The number of detected lymph nodes in each group was summed, and pathological examination was conducted. The number of lymph nodes (dyedor not dyed) and the location of metastatic nodes were recorded separately.

RESULT

In the nano-carbon group the average number of eliminated lymph nodes is significantly more than that of the control group(P<0.05). The metastasis lymph nodes in the nano-carbon group was higher than that in the control group(P<0.01). Among 100 cases, 2% had temporary vocal cord palsy, and 8% had temporary hypoparat hyroidism. No case of permanent vocal cord palsy or permanent hypocalcemia was observed.

CONCLUSION

The dyed lymph nodes can be easily identified and can be used as a guide for lymphnodes dissection in papillary thyroid carcinoma operation.

[Effects of methane stress on oxidation rates and microbial community structures in different landfill cover soils]

As compared with the ordinary landfill cover material, clay soil, the effect of methane stress on oxidation rate and microbial community structure was investigated in waste soil (material from biologically treated municipal solid waste). The results showed that the moisture content of the clay soil was low, due to the low water retaining capacity. As environmental temperature and rainfall changed, the clay soil caked and inhibited methanotrophs growth. However, with a high organic matter, water-holding capacity and porosity, the waste soil provided a favor condition for methanotrophs growth and propagation. After exposure to methane flow for 120 days, methane oxidation potential in the middle and bottom layers of the waste soil column increased to 11.25-13.48 micromol/(g x h), which was 10.4-24.5 times higher than that in clay soil column. The topsoils were both found to be dried and inhibit methane oxidation. Methane oxidation (removal) efficiency by the waste soil column reached 48.3% at the end of the experiment, which was 5-6 times higher than that by the clay soil column. The amounts of the phospholipid fatty acid (PLFA) biomarks 16:1 omega 8c and 18:1 omega 8c for Type I and II methanotrophs, respectively, showed that a strong linear relationship was observed between methane oxidation potential and PLFA 18:1 omega 8c content in soil samples.