Zinc depletion causes multiple defects in ovarian function during the periovulatory period in mice

Shortly before ovulation, the oocyte acquires developmental competence and granulosa cells undergo tremendous changes including cumulus expansion and luteinization. Zinc is emerging as a key regulator of meiosis in vitro, but a complete understanding of zinc-mediated effects during the periovulatory period is lacking. The present study uncovers the previously unknown role of zinc in maintaining meiotic arrest before ovulation. A zinc chelator [N,N,N',N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN)] caused premature germinal vesicle breakdown and associated spindle defects in denuded oocytes even in the presence of a phosphodiesterase 3A inhibitor (milrinone). TPEN also potently blocked cumulus expansion by blocking induction of expansion-related transcripts Has2, Ptx3, Ptgs2, and Tnfaip6 mRNA. Both meiotic arrest and cumulus expansion were rescued by exogenous zinc. Lack of cumulus expansion is due to an almost complete suppression of phospho-Sma- and Mad-related protein 2/3 signaling. Consistent with a decrease in phospho-Sma- and Mad-related protein 2/3 signaling, TPEN also decreased cumulus transcripts (Ar and Slc38a3) and caused a surprising increase in mural transcripts (Lhcgr and Cyp11a1) in cumulus cells. In vivo, feeding a zinc-deficient diet for 10 d completely blocked ovulation and compromised cumulus expansion. However, 42.5% of oocytes had prematurely resumed meiosis before human chorionic gonadotropin injection, underscoring the importance of zinc before ovulation. A more acute 3-d treatment with a zinc-deficient diet did not block ovulation but did increase the number of oocytes trapped in luteinizing follicles. Moreover, 23% of ovulated oocytes did not reach metaphase II due to severe spindle defects. Thus, acute zinc deficiency causes profound defects during the periovulatory period with consequences for oocyte maturation, cumulus expansion, and ovulation.

Regulation of radiosensitivity by HDAC inhibitor trichostatin A in the human cervical carcinoma cell line Hela

Histone deacetylase (HDAC) inhibitors play an important role in inducing growth arrest, differentiation, and/or apoptosis in cancer cells. Given their ability to disrupt critical biological processes in cancer cells, these agents are emerging as potential therapeutics for cancer. Recently, it has been identified that HDAC inhibitors can also efficiently enhance the radiation sensitivity of cells, both in vitro and in vivo. In this study, we investigated whether the potent HDAC inhibitor, Trichostatin A, modulates the radiation sensitivity of the human cervical carcinoma cell line Hela under hypoxic conditions. We concluded that TSA could significantly inhibit the proliferation of Hela cells in a dose-and time-dependent manner under normoxic and hypoxic conditions. Hypoxia resulted in the cervical carcinoma Hela cells resistant to TSA. The findings from clonogenic survival assays indicate that incubation with TSA for 24 hours prior to irradiation enhances the radiation sensitivity of Hela cells under hypoxic conditions. More generally, we found Hela cells under hypoxic conditions treated with TSA could significantly down-regulate the expressions of HIF-1alpha and VEGF proteins. Taken together, our results demonstrated that TSA acts as a powerful radiosensitizer in Hela cells under hypoxic conditions probably by down-regulated expression of HIF-1alpha and VEGF proteins.

Elective neck dissection in papillary thyroid carcinoma patients

BACKGROUND

This study was designed to review the diagnostic performance of cervical lymph node metastases for assessment of elective neck dissection in papillary thyroid carcinoma patients and to determine the technique (using Methylene blue dye) that demonstrated the highest success rate with regard to the detection rate and sensitivity.

METHODS

Preoperative 24 h, 1 mL of 1.0% methylene blue was injected into the parenchyma surrounding the primary tumor with ultrasound guidance by a 27-gauge needle. Intra-operative lymph nodes that were stained blue and/or having afferent lymphatic channels stained blue were also considered to be excised. All stained blue nodes were defined by levels, number, site and were sent for frozen and permanent section histologic analysis.

RESULTS

For the 132 patients who underwent methylene blue dye, 1373 lymph nodes were removed. 7 lymph nodes had negative dye results but, in the end, had metastatic lymph nodes. 120 lymph nodes had both negative dye and lymph node results. The number of blue-dye lymph nodes was 1246 and the number of pathology metastatic nodes was 1079, so the pathological diagnose accordance rate was 87.8 percent. The nodal metastases often occur at level VI, IV, III, then in level II, and less in level I and V.

CONCLUSIONS

This method using methylene blue dye is feasible technically and is safe, and the findings correlate with cervical lymph node status. According to the pattern of blue dye lymph nodes and frozen-section histologic analysis, performing elective neck dissection is a reliable, safe surgical procedure for PTC.

Inactivation of the von Hippel-Lindau tumor suppressor leads to selective expression of a human endogenous retrovirus in kidney cancer

A human endogenous retrovirus type E was recently found to be selectively expressed in most renal cell carcinomas (RCC). Importantly, antigens derived from this provirus are immunogenic, stimulating cytotoxic T-cells that kill RCC cells in vitro and in vivo. Here we show HERV-E expression is restricted to the clear cell subtype of RCC (ccRCC) characterized by an inactivation of the von Hippel-Lindau (VHL) tumor suppressor gene with subsequent stabilization of hypoxia-inducible transcription factors HIF-1α and -2α. HERV-E expression in ccRCC linearly correlated with HIF-2α levels and could be silenced in tumor cells by either transfection of normal VHL or siRNA inhibition of HIF-2α. Using chromatin immunoprecipitation, we demonstrated that HIF-2α can serve as transcriptional factor for HERV-E by binding with HIF response elements (HRE) localized in the proviral 5′LTR. Remarkably, the LTR was found to be hypomethylated only in HERV-E-expressing ccRCC while other tumors and normal tissues possessed a hypermethylated LTR preventing proviral expression. Taken altogether, these findings provide the first evidence that inactivation of a tumor suppressor gene can result in aberrant proviral expression in a human tumor and give insights needed for translational research aimed at boosting human immunity against antigenic components of this HERV-E.

Diffuse alveolar hemorrhage in systemic lupus erythematosus: a retrospective study in China

The objective of this study was to determine the clinical features of systemic lupus erythematosus (SLE) patients with diffuse alveolar hemorrhage (DAH). The medical records of 29 patients with DAH among 2133 SLE patients admitted to Peking Union Medical College Hospital from January 2004 to January 2009 were reviewed in this retrospective study. It was found that hypoxemia (100%), dyspnea (90%), cough (79%) and fever (72%), rather than hemoptysis (66%), were the most common symptoms. The most common extrapulmonary presentation was renal involvement (90%). In about 60% of patients nosocomial infection was also present. The mean drop in hemoglobin was 32 ± 10.9 g/l. Mean Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) was 17 ± 9. All patients received high-dose corticosteroid therapy and most were also given immunosuppressive agents. Rates of concomitant nosocomial infection and mechanical ventilation in non-survivors were higher than those of survivors (p < 0.05). DAH is a rare and catastrophic event in SLE. DAH can occur at any stage of the disease course; it usually occurs in patients with active SLE, and is frequently complicated by lupus nephritis. Some patients may have no hemoptysis. Early aggressive management with high-dose steroids and cyclophosphamide is advocated.

Localization of phosphorylated SMAD proteins in granulosa cells, oocytes and oviduct of female mice

SMAD signaling is essential for follicular development. The distribution of activated (phosphorylated) SMADs during folliculogenesis has not been described in detail. The present results indicate that oocytes from preantral and antral follicles contain the mRNA for the receptor regulated Smads (-1, -2, -3, -5 and -9), Smad4 (co-SMAD), and Smad6 and Smad7 (inhibitory SMADs). Levels of Smad5, Smad6 and Smad7 mRNA decreased in fully-grown oocytes compared to growing oocytes. Immunostaining for pSMAD1/5/9, pSMAD2 and pSMAD3 was evident in oocytes from primordial, primary, secondary and antral follicles. We also observed substantial staining for pSMADs in intact fully-grown oocytes from antral follicles. In granulosa cells, immunostaining for both pSMAD2/3 and pSMAD1/5/9 was apparent in preantral granulosa cells from primordial to secondary follicles. In antral follicles, immunostaining for pSMADs became more intense in the cumulus cells surrounding the oocyte. Immunostaining for pSMAD2 and pSMAD1/5/9 was also apparent in the epithelium lining of the oviduct. Clearly, oocytes, preantral granulosa cells, cumulus cells and the epithelium of the oviduct are major targets of SMAD-mediated pathways in female reproductive tissues. The finding that pSMAD pathways are active in oocytes raises new questions regarding the role of TGF-beta superfamily members in directly promoting oocyte development. The extent to which defects in pSMAD signaling in oocytes or the oviduct contribute to infertility in humans or animals remains an open question.

A herbicide-resistant ACCase 1781 Setaria mutant shows higher fitness than wild type

It is often alleged that mutations conferring herbicide resistance have a negative impact on plant fitness. A mutant ACCase1781 allele endowing resistance to the sethoxydim herbicide was introgressed from a resistant green foxtail (Setaria viridis (L.) Beauv) population into foxtail millet (S. italica (L.) Beauv.). (1) Better and earlier growth of resistant plants was observed in a greenhouse cabinet. (2) Resistant plants of the advanced BC7 backcross generation showed more vigorous juvenile growth in the field, earlier flowering, more tillers and higher numbers of grains than susceptible plants did, especially when both genotypes were grown in mixture, but their seeds were lighter than susceptible seeds. (3) Field populations originating from segregating hybrids had the expected allele frequencies under normal growth conditions, but showed a genotype shift toward an excess of homozygous resistant plants within 3 years in stressful conditions. Lower seed size, lower germination rate and perhaps unexplored differences in seed longevity and predation could explain how the resistant plants have the same field fitness over the whole life cycle as the susceptible ones although they produce more seeds. More rapid growth kinetics probably accounted for higher fitness of the resistant plants in adverse conditions. The likelihood of a linkage with a beneficial gene is discussed versus the hypothesis of a pleiotropic effect of the ACCase resistance allele. It is suggested that autogamous species like Setaria could not develop a resistant population without the help of a linkage with a gene producing a higher fitness.

Growth inhibition of Microcystis aeruginosa by white-rot fungus Lopharia spadicea

Harmful cyanobacterial blooms cause water deterioration and threaten human health. It is necessary to remove harmful cyanobacteria with useful methods. A bio-treatment may be one of the best ways to do this. A strain of specific white-rot fungus, Lopharia spadicea, with algicidal ability was isolated. Its algicidal ability on algae under various conditions was determined using three main influence factors: initial chlorophyll-a content, initial pH, and algal cell mixture. The result showed that the chlorophyll-a content of Microcystis aeruginosa FACHB-912, Oocystis borgei FACHB-1108, and Microcystis flos-aquae FACHB-1028 decreased from 798+/-13, 756+/-40, and 773+/-24 microg/L to 0 within 39 h. L. spadicea could also remove more than 95% chlorophyll-a when initial chlorophyll-a content increased from 397+/-13 to 2,132+/-4 microg/L. Moreover, the strain has great removal ability under a broad initial pH range of 5.5 to 9.5. The chlorophyll-a content of the three algal strain mixtures decreased from about 672+/-23 microg/L to 0 within 45 h. After superoxide dismutase (SOD) and malondialdehyde (MAD) were assessed in a co-culture of L. spadicea, it was observed that an increase in MAD content was correlated with the decrease in chlorophyll-a content of M. aeruginosa FACHB-912. This result suggested that the algae was not only greatly inhibited but also severely damaged by the fungus.

Regeneration of foreign genes co-transformed plants of Medicago sativa L by Agrobacterium rhizogenes

Gene encoding sulphur amino acid-rich protein (HNP) and rol genes were transferred into Medicago sativa L (alfalfa) mediated by Agrobacterium tumafeciens. Regeneration of transgenic plants was induced successfully from hairy root tissue of cotyledon in alfalfa. Cotyledon tissues were an ideally transformed recipient. There was a negative correlation between age of hairy roots and embryogenesis frequency in alfalfa. Production of co-transformed plants with greater yield and super quality was important for development of new alfalfa varieties.

Sjögren's syndrome-onset lupus patients have distinctive clinical manifestations and benign prognosis: A case—control study

The objective of this study was to investigate the clinical characteristics and prognosis of Sjögren’s syndrome-onset systemic lupus erythematosus (SS/SLE) patients. Medical charts of 41 consecutive SS/SLE inpatients admitted to Peking Union Medical College Hospital (PUMCH) from February 1998 to February 2008 were systematically reviewed, including demographic data, clinical features, laboratory findings, treatment as well as outcomes. Two hundred and fourteen cases were randomly selected as controls from 2331 SLE-only inpatients treated in PUMCH at the same time period. There were significant differences between SS/SLE and SLE-only patients in the following manifestations (p < 0.05): (1) sex ratio (F/M) (41/0 versus 184/30), age (42.8 ± 41.0 years versus 31.8 ± 31.0 years), disease duration (113.8 ± 84.0 months versus 44.9 ± 18.0 months); (2) clinical features, xerostomia (85.4% versus 6.1%), xerophthalmia (75.6% versus 2.3%), renal tubular acidosis (21.9% versus 0%), interstitial lung disease (12.2% versus 2.8%), facial rash (9.8% versus 46.3%), nephrotic syndrome (7.3% versus 31.3%), central nervous system involvement (4.9% versus 19.6%); (3) laboratory findings, ESR (64.6±75.0mm/h versus 46.5±34.0mm/h), C4 (14.8 ± 12.2 g/dl versus 12.0 ± 10.9 g/dl), IgG elevation (56.4% versus 29.9%) and IgA elevation (38.5% versus 20.4%), RF, anti-SSA and anti-SSB positive rates (70.8% versus 20.3%, 82.9% versus 43.4% and 39.0% versus 7.9%); (4) SLEDAI score (8.0 ± 8.0 versus 10.2 ± 10.0), glucocorticoid treatment (methylprednisolone bolus/1—2 mg kg-1 day-1 prednisone/<1 mg kg-1 day-1 prednisone) (8/26/7 versus 91/102/21), and importantly, rate of death and/or severe irreversible organ failure (2.4% versus 14.9%). SS/SLE patients were followed up for 33.0 ± 34.0 months, 40 cases remained stable at a low dose of corticosteroid. In conclusion, different from SLE-only patients, SS/SLE patients have distinctive clinical manifestations and benign prognosis that require less vigorous treatment with glucocorticoids and/or immunosuppressants. Lupus (2010) 19, 197—200.

Use of short echo time two-dimensional 1H-magnetic resonance spectroscopy in temporal lobe epilepsy with negative magnetic resonance imaging findings

We evaluated short echo time two-dimensional 1H magnetic resonance spectroscopy (2D-1HMRS) with the point-resolved spatial selection (PRESS) protocol in temporal lobe epilepsy (TLE) patients with negative magnetic resonance imaging (MRI) findings and described the characteristics of 2D-(1)HMRS in the epileptic focus. Thirty-eight TLE patients with negative conventional MRI findings and 10 healthy controls were studied by 2D-1HMRS. A 128-channel prolonged video-electroencephalographic (EEG) method was used as the standard for epileptogenic focus localization to evaluate N-acetyl aspartate/(choline + creatine + phosphocreatine) (NAA/[Cho + Cr-PCr]), glutamate + glutamine/creatine (Glx/Cr-PCr) and myo-inositol/Cr-PCr ratios in patients with negative MRI findings. The 2D-1HMRS showed that 32/38 patients and all healthy controls had stable baselines and good signal-to-noise ratios. Compared with the healthy controls, 32 patients showed abnormal NAA/(Cho + Cr-PCr) ratios in the hippocampus and, in 25 of these patients, focus lateralization agreed with the EEG. It is concluded that short echo time 2D-1HMRS with the PRESS protocol can help find abnormalities in lateralization of temporal epilepsy in patients with negative MRI findings.

In vivo selection of human embryonic stem cell-derived cells expressing methotrexate-resistant dihydrofolate reductase

Human embryonic stem cells (hESCs) provide a novel source of hematopoietic and other cell populations suitable for gene therapy applications. Preclinical studies to evaluate engraftment of hESC-derived hematopoietic cells transplanted into immunodeficient mice demonstrate only limited repopulation. Expression of a drug resistance gene, such as Tyr22-dihydrofolate reductase (Tyr22-DHFR), coupled to methotrexate (MTX) chemotherapy has the potential to selectively increase engraftment of gene-modified hESC-derived cells in mouse xenografts. Here, we describe the generation of Tyr22-DHFR – GFP expressing hESCs that maintain pluripotency, produce teratomas and can differentiate into MTXr-hemato-endothelial cells. We demonstrate that MTX administered to nonobese diabetic/severe combined immunodeficient/IL-2Rγc^null (NSG) mice after injection of Tyr22-DHFR-derived cells significantly increases human CD34⁺ and CD45⁺ cell engraftment in the bone marrow (BM) and peripheral blood of transplanted MTX-treated mice. These results demonstrate that MTX treatment supports selective, long-term engraftment of Tyr22-DHFR-cells in vivo, and provides a novel approach for combined human cell and gene therapy.

Prevalence, risk factors and outcome of digital gangrene in 2684 lupus patients

The aim of the study is to assess the clinical characteristics, risk factors and outcome of patients with systemic lupus erythematosus (SLE) complicated with digital gangrene. In all, 2684 consecutive SLE inpatients admitted to Peking Union Medical College Hospital from December 1997 to August 2007 were studied. Demographic data, clinical features, laboratory findings as well as therapeutic regimens were systematically reviewed and a database was established. Cases with digital gangrene were identified and followed up. 1) Eighteen patients with SLE were complicated with digital gangrene, the average age at event was 33.1 ± 11.8 years and the average disease duration was 99.1 ± 60.1 months. 2) Patients with SLE, with long disease duration (≥4 years), Raynaud’s phenomenon and elevated serum C-reactive protein (CRP) were more likely to develop digital gangrene, P = 0.006, 0.001, and 0.031, respectively, OR = 1.03 (95% CI 1.01, 1.04), 35.76 (95% CI 4.67, 273.83) and 9.93 (95% CI 1.23, 80.30), respectively. 3) Fifteen gangrene patients started prednisone ≥1 mg/kg/d, and 18 were treated with cyclophosphamide, although 8 cases failed and ultimately received digital amputation. Prompt corticosteroid treatment (prednisone ≥1 mg/kg/d started within 3 weeks) decreased the hazard of amputation, P = 0.073, HR = 0.13 (95% CI 0.01, 1.21). Long disease duration, Raynaud’s phenomenon and elevated serum CRP were independent predictive factors for SLE to develop digital gangrene. Early and aggressive corticosteroid treatment prevented gangrene from progression and improved prognosis.

Protective factors relating to decreased risks of adolescent suicidal behaviour

BACKGROUND

Suicide has been identified as one of the three leading causes of death in adolescents and young adults. No previous study in China has tested the association between protective factors and urban adolescents' suicidal behaviours. In this study we tested the hypothesis that suicidal behaviours would be associated with multiple protective factors.

METHODS

A stratified random of 9015 students from 100 junior middle schools in Beijing, Hangzhou, Wuhan and Urumqi completed the Chinese version of Global School-Based Student Health Survey.

RESULTS

Overall, 17.4% of students had seriously considered attempting suicide, and 8.1% had made a specific plan to attempt suicide during the 12 months preceding the survey. The students in Wuhan (18.7%) and Urumqi (20.8%) cities were significantly more likely than students in Beijing (14.4%) and Hangzhou (14.4%) to have suicidal ideation (chi2 = 45.9, P < 0.001). Female students were significantly more likely than male students to have suicidal ideation and have made suicide attempts [odds ratio (OR) = 1.4, P < 0.001]. Results indicated that the rates of suicidal ideation and suicide attempts increased with age (OR = 1.44, P < 0.001). Multivariate logistic regression models showed that suicide risk tended to decrease significantly when 'days of missed classes or school without permission were less than one', and when students thought students in their school were kind and helpful most of the time or always', 'parents or guardians checked to see if homework was done most of the time or always', 'parents or guardians understood their problems and worries most of the time or always' and 'parents or guardians really know what they are doing with their free time most of the time or always'.

CONCLUSIONS

Adolescent suicide behaviour should be a serious problem. Measures can be taken to prevent suicide by observing the factors significantly linked to suicidal behaviour. Steps can then be taken to identify adolescents who have serious suicidal ideation so that intervention can be taken to reduce the suicidal rate.

[Establishment of a rabbit model of Acanthamoeba keratitis]

AIM

To establish an animal model of Acanthamoeba keratitis.

METHODS

Six New Zealand white rabbits were each injected intrastromally with Acanthamoeba suspension 3 days after subconjunctival injection with dexamethasone.

RESULTS

All of the 6 rabbits developed keratitis. Acanthamoeba protozoa were identified by the methods of corneal scraping with 10% potassium hydroxide wet mount examined under microscope, corneal protozoa culture and pathological section examination.

CONCLUSION

A rabbit model of Acanthamoeba keratitis was established.

220 SYNERGISTIC EFFECT ON EMBRYO DEVELOPMENT BY INCLUSION OF SUPPLEMENTAL EMBRYOS IN AGAR CHIPS

The main scope of this study was to evaluate the likelihood of a helper effect of agar-embedded cleaved embryos on a low number of free embryos at a similar stage of development within the same culture droplet. Such an improved system could be beneficial within ovum pickup/in vitro embryo production (OPU/IVEP) combined protocols whenever a low number of OPU-derived cleaved embryos are produced per donor. Oocytes were recovered from abattoir ovaries, and after in vitro maturation (IVM) and in vitro fertilization (IVF), presumptive zygotes were deprived of cumulus investment and allocated into culture droplets for 24 h. At 48 h from IVF, 4- to 8-cell cleaved embryos were randomly allocated into a control and a treatment group. Control groups consisted of 1, 3, 5, and 10 embryos, respectively, in 50-μL droplets. Treatment groups consisted of 1, 3, and 5 free embryos with the addition of 9, 7, and 5 embryos, respectively, at a similar stage of development embedded in agar chips, so as to reach a total number of 10 cleaved embryos in each culture droplet. Culture was performed for both the control and treatment groups in SOF medium droplets covered with mineral oil, with the supplementation of essential and nonessential amino acids in a controlled gas atmosphere consisting of 5% CO2, 7% O2, and 88% N2 at 39°C. Final embryo output was checked at Day 7 from IVF. When considering only free embryos, the difference in progression to blastocyst development was highly significant between the control and treatment groups: 1) group 1 v. 1 + 9: 6.6 v. 84.3% (P = 0.00000); 2) group 3 v. 3 + 7: 11.1 v. 41.3% (P = 0.00001); 3) group 5 v. 5 + 5: 24.4 v. 42.2% (P = 0.00001). Rate of blastocyst development in the control group containing 10 cleaved embryos was not significantly different from free cleaved embryos in the 3 + 7 (39.2 v. 41.3%, P = 0.71) and 5 + 5 treatment groups (39.2 v. 42.2%, P = 0.54), but was significantly lower when compared with the 1 + 9 treatment group (39.2 v. 84.3%, P = 0.000). For 1, 3, 5, and 10 control group embryos, the numbers of replicates and total cleaved embryos used (n) were 30 (n = 30), 27, (n = 81), 27 (n = 135), and 39 (n = 390), respectively. For the 1 + 9, 3 + 7, and 5 + 5 treatment group embryos, the numbers of replicates and total cleaved embryos used were 32 (n = 32), 29 (n = 87), and 27 (n = 135), respectively. In conclusion, a beneficial effect of agar-embedded embryos on the development of free embryos within the same culture droplet was shown. A striking improvement in late-stage embryo development was particularly evident when considering the 1 v. 1 + 9 control and treatment groups. These results may foster a different strategic approach in in vitro culture to enhance embryo development from highly valuable donors.

Relationship between protein expression of VEGF-C, MMP-2 and lymph node metastasis in papillary thyroid cancer

Papillary thyroid cancer (PTC) is a common malignancy and has a good prognosis after appropriate treatment. PTC cells spread mainly by lymph node metastasis (LNM), but the mechanism is not well understood. Expression of vascular endothelial growth factor C (VEGF-C) and matrix metalloproteinase 2 (MMP-2) protein was studied immunohistochemically from the archived specimens of 65 PTC patients who initially presented without LNM. In this retrospective study, the frequency of expression differed significantly between thyroid cancer tissue and adjacent normal follicular epithelium (VEGF-C 78.5% and 20.0%, respectively; MMP-2 81.5% and 36.7%, respectively). LNM developed in 35 of the patients during 5 - 15 years of follow-up, by the end of which the frequencies of expression of VEGF-C and MMP-2 protein expression were 91.4% and 94.3%, respectively. Both VEGF-C and MMP-2 protein expression were significantly more frequent in PTC with LNM than without LNM. VEGF-C and MMP-2 protein expression levels were significantly correlated with LNM and it is, therefore, feasible that VEGF-C and MMP-2 may be useful as tumour markers of PTC with cervical LNM.