Radioiodine therapy of thyroid carcinoma following Pax-8 gene transfer

The thyroid transcription factor Pax-8 could bind with the promoter/enhancer of thyroid-specific genes such as thyroglobulin (Tg), thyroperoxidase (TPO) and sodium iodide symporter (NIS), and regulate the expression of these proteins in thyrocyte. Promoting iodide accumulation in tumor cells by re-expression of Pax-8 provides a possible strategy for radioiodine therapy of tumor. Therefore, we investigated the effect of Pax-8 gene transfer on radioiodine therapy of thyroid carcinoma. The human Pax-8 gene was transfected into the human thyroid carcinoma (K1 and F133) cells by the recombinant adenovirus vector. Although the NIS mRNA was not detected, the expression of mRNA and proteins of Tg and TPO in AdPax-8-infected F133 cells were activated by Pax-8. Iodide uptake in thyroid carcinoma cells was reactivated by Pax-8 (increasing 3.3-fold in K1 cells and 5.7-fold in F133 cells). Moreover, Pax-8 promoted iodide organification and the retention time of iodine in Pax-8-expressing cells apparently prolonged in vitro and in vivo (P<0.05). Pax-8-expressing thyroid carcinoma cells were selectively killed by radioiodine. The AdPax-8-infected tumors in vivo clearly visualized in scanning images at 12 h after administration of radioiodine. These results indicate that Pax-8 can promote iodide uptake, and specifically prolong the retention time of iodide in thyroid cancer in vitro and in vivo by promoting the expression of TPO and Tg proteins. Pax-8 gene transfection may lead to effective radioiodine therapy of tumor.

Comparative study of retinal nerve fibre layer measurement by RTVue OCT and GDx VCC

AIM

To evaluate the diagnostic performances and correlations of retinal nerve fibre layer (RNFL) thickness measured by RTVue OCT and GDx variable corneal compensation (VCC).

METHODS

The total and regional RNFL thickness were measured by RTVue OCT and GDx VCC in 62 normal eyes and 72 glaucomatous eyes of Chinese subjects. The RNFL thickness profiles of normal and glaucomatous eyes by RTVue OCT are plotted. Correlations of RNFL thickness measured by RTVue OCT and GDx VCC were assessed using the Pearson correlation. The discriminating abilities of the two techniques for detection of glaucoma were compared by the area under the receiver operating characteristic curves (AUC).

RESULTS

RTVue OCT demonstrated double hump patterns in the RNFL profiles. In both normal and glaucomatous subjects, the peaks were located in the superotemporal (ST) and inferotemporal (IT) regions, and the troughs were located at the nasal (NU+NL) and temporal (TU+TL) regions. Despite poor agreement, a high correlation (r=0.821) was found between the mean RNFL measurements by RTVue OCT and GDx VCC. For RTVue OCT, the highest AUCs were mean RNFL (AUC=0.914) and inferior mean RNFL (AUC=0.909). The nerve fibre indicator (AUC=0.856) and inferior RNFL (AUC=0.852) achieved the highest AUCs among all the GDx VCC measurements. The mean RNFL in RTVue OCT had the greatest AUC in the two devices. There was a significant difference in comparing the AUCs of the mean RNFL thickness obtained by RTVue OCT and GDx VCC (p=0.009).

CONCLUSIONS

Although there were absolute value differences in RNFL thickness, a high correlation was observed between RTVue OCT and GDx VCC. RTVue OCT shows a reasonable ability to distinguish normal from glaucomatous eyes.

CD14, a key candidate gene associated with a specific immune response to cockroach

BACKGROUND

Sensitization to cockroach allergen is one of the strongest predictors of asthma morbidity, especially among African Americans.

OBJECTIVE

Our aims were to determine the genomic basis of cockroach sensitization and the specific response to cockroach antigen.

METHODS

We investigated the Th1/Th2 cytokine profile of co-cultured plasmacytoid dendritic cells (pDCs) and CD4+ T cells and the 'transcript signature' of the immune response to cockroach antigen using high-throughput expression profiling of co-cultured cells.

RESULTS

We observed significantly elevated levels of IL-13, IL-10, and TNF-alpha, but undetectable levels of IL-12p70 and IFN-alpha, when cultures were exposed to crude cockroach antigen. A significant difference was observed for IL-13 between cockroach-allergic and non-allergic individuals (P=0.039). Microarray analyses demonstrated a greater response at 48 h compared with 4 h, with 50 genes being uniquely expressed in cockroach antigen-treated cells, including CD14, S100A8, CCL8, and IFI44L. The increased CD14 expression was further observed in purified pDCs, human monocytic THP-1 cells, and the supernatant of co-cultured pDCs and CD4+ T cells on exposure to cockroach extract. Furthermore, the most differential expression of CD14 between cockroach allergy and non-cockroach allergy was only observed among individuals with the CC 'high-risk' genotype of the CD14-260C/T. Ingenuity Pathways Analysis analyses suggested the IFN signalling as the most significant canonical pathway.

CONCLUSION

Our results suggest that these differentially expressed genes, particularly CD14, and genes in the IFN signalling pathway may be important candidates for further investigation of their role in the immune response to cockroach allergen.

Compare the diagnostic value of FLT and FDG PET/CT in assessment of regional lymph nodes in thoracic esophageal squamous cell carcinoma

e15620

Background: To determine whether FLT PET/CT can detect regional lymph nodes metastases in untreated thoracic esophageal squamous cell carcinoma. In view of the reported high sensitivity of FDG PET/CT for the evaluation of thoracic nodules of esophageal carcinoma, we additionally performed FDG PET/CT for direct comparison with that of FLT. Methods: From March 2008 to December 2008, 18 patients with thoracic esophageal squamous cell carcinoma underwent dual-tracer PET/CT examinations before surgery. The results of reviewing side-by-side FDG PET/CT and FLT PET/CT images for the diagnosis of locoregional lymph node metastases were compared prospectively in relation to pathologic findings. The PET images were visually inspected with the maximum standardized uptake value (SUVmax) determined from a circular region of interest (ROI) over the entire lesion. The differential threshold for malignancy was set as SUVFDG≥2.5, and SUVFLT≥1.4, respectively. Results: All patients underwent esophagectomy and lymphadenectomy, and pathologic examination confirmed nodes positive for metastasis in 14 patients and 42 of 344 excised nodes. The uptake of FDG (median SUVmax, 5.59; range, 2.5–10.6) in locoregional lymph nodes metastasis was significantly higher than that of FLT (median SUVmax, 2.93; range, 1.6–4.6). There were 14 false positive nodes in FDG PET and only 3 in FLT PET, 7 false negative nodes in FDG PET, while 11 false negative nodes in FLT PET. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of FLT PET/CT were 73.81%, 99.01%, 95.93%, 91.18% and 96.45%, respectively, whereas those of FDG PET/CT were 83.33%, 95.36%, 93.90%, 71.43% and 95.36%, respectively. P values were 0.425, 0.014, 0.298, 0.055, and 0.541, respectively. Conclusions: FLT uptake in regional lymph node of esophageal carcinoma is significantly lower compared with FDG uptake.FLT PET has fewer false-positive findings compared with FDG PET. The specificity of FLT PET/CT is higher than that of FDG. We suggest that esophageal carcinoma N-staging need to combine FLT with FDG PET/CT images.

No significant financial relationships to disclose.

Prognostic significance of sentinel nodes metastases in breast cancer patients without axillary node dissection or axillary radiotherapy: CBCSG-001 trial

Abstract #1015

Background: China multicenter study of sentinel lymph node biopsy (SLNB) substituting axillary lymph node dissection (ALND) in breast cancer– CBCSG-001 trial was conducted from Jan. 2002 to Jun. 2007, with 1,970 SLNB pts recruitment. One of the second objectives of the CBCSG–001 trial was to evaluate the optimal methods and intervals for the detection of SLN macrometastases, MMs and isolated tumor cells (ITCs) and their prognostic significance in patients received SLNB without ALND or axillary radiotherapy.&#x2028; Material and Methods: Two hundred and forty-five continuous breast cancer patients with 569 SLNs identified “negative” with routine standard HE stain carried on initial 4 levels were retrospectively analyzed. All the patients received SLNB only, without ALND or axillary radiotherapy after the diagnoses of metastases in their SLNs later. All SLNs were step sectioned (SS) at 100µm interval, and for each level both HE and IHC with AE1/AE3 were performed. Forty-nine patients were identified to have metastases, with macrometastases of 12.2%, micrometastases of 61.2%, and isolated tumor cells of 26.5%. All patients had received SLNB only, with no ALND and axillary radiotherapy.&#x2028; Results: Of the 245 patients, breast conserved surgery and SLNB were performed on 106 patients (43.3%), and mastectomy and SLNB in 139 patients. With a median follow up of 50 months, there were 20 breast related events occurred. The disease free survival (DFS) of patients with routine negative SLNs was 91.6%, and 93.9% for patients with positive SLNs after SS with HE+IHC (p&gt;0.05). The overall survival (OS) were 97.4% and 98.0 for each group, respectively (p&gt;0.05). The results were the same for patients with macrometastases, micrometastases, and isolated tumor cells. Due to the relatively less events occurred, the DFS and OS had not been calculated for macrometastases, micrometastases, and isolated tumor cells, separately.&#x2028; Discussion and Conclusions: Without ALND and axillary radiotherapy, there were no significant differences of DFS and OS between patients with routine negative SLNs and patients with positive SLNs after SS with HE+IHC. It might be safe for these patients to receive SLNB only. The possible reasons might include: SLNs were the only positive lymph nodes in more than 60% patients, effective adjuvant systemic therapy for regional lymph nodes just as neoadjuvant chemotherapy, axillary coverage of radiotherapy in patients with breast conserved therapy, and the relatively less events occurred during the 50 months follow up period.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1015.

Optimal detection of micrometastases in sentinel lymph node of breast cancer: CBCSG-001 trial

Abstract #1011

Background: Although sentinel lymph node biopsy (SLNB) has become the method of choice for axillary staging, the extent of the pathological examination (HE or IHC, the number or intervals of sections) described in the literature differed considerably between studies, particularly for the detection of micrometastases (MMs). As one of the second objectives of the CBCSG–001 trial (China multicenter study of sentinel node biopsy substituting axillary node dissection), our aim was to evaluate the optimal methods and intervals for the detection of SLN macrometastases, MMs and isolated tumor cells (ITCs).&#x2028; Material and Methods: Two hundred and forty-five continuous breast cancer patients with 569 SLNs identified “negative” with standard HE stain carried on initial 4 levels were retrospectively analyzed. All SLNs were step sectioned (SS) at 100µm interval, and for each level both HE and IHC with AE1/AE3 were performed. Then HE and IHC detection rates were analyzed at 100-, 200-, 300-, 400-, and 500µm intervals for the detection of macrometastases, MMs and ITCs.&#x2028; Results: In 245 cases with original SLN negative cases, 36 (14.7%), 49 (20.0%) and 49 (20.0%) cases were found to had metastases with SS HE, SS IHC, and SS HE+IHC, respectively (SS IHC/ SS HE+IHC vs. SS HE, p&gt;0.05). In all the 5741 sections, metastases were found in 180 sections (3.1%) by SS HE, 307 (5.4%) by SS IHC, and 322 (5.6%) by SS HE+IHC (p=0.000). The metastases included macrometastases 12.2%, MMs 61.2%, and ITC 26.5%. The detection rates of MMs were 7.8%, 12.2%, and 12.2%, respectively (SS IHC/ SSHE+IHC vs. SS HE, p&gt;0.05). The detection rates of ITCs were 4.5%, 5.3%, and 5.3%, respectively (p&gt;0.05). The detection rates of metastases were significantly higher in patients with invasive lobular carcinoma (57.1%) than with invasive ductal carcinoma (16.7%, p=0.001), but no significant differences were found among different ages, tumor sizes, locations, grades, ER, PR, and HER-2 status (all p&gt;0.05). The detection rates of metastases at 100-, 200-, 300-, 400-, and 500-µm intervals by SS HE were 14.7%, 13.5%, 11.4%, 8.6%, and 7.8%, respectively. No significant differences were found between 100- and 200-µm intervals (p=0.697), and between 100- and 300-µm (p=0.284), while p&lt;0.05 between 100-µm and other intervals. The detection rates of metastases at 100-, 200-, 300-, 400-, and 500-µm intervals by SS HE+IHC were 20.0%, 18.8%, 18.0%, 16.3%, and 13.1%, respectively. No significant difference was found between 100- and 200-µm intervals (p=0.732), 100- and 300-µm (p=0.565), and between 100- and 400-µm (p=0.292), while p=0.041 between 100-µm and 500-µm.&#x2028; Conclusion: SS HE could significantly increase the detection rate of SLN metastasis compared to our routine 4 levels HE pathological examination. SS HE+IHC could further improve the detection of SLN metastases. The detection rates of metastases were significantly higher in patients with invasive lobular carcinoma than those with invasive ductal carcinoma. The optimal interval for the detection of micrometastases in SLN was 300-µm with SS HE, and 400-µm with SS HE+IHC.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1011.

Effects of DNAzymes targeting Aurora kinase A on the growth of human prostate cancer

Aurora kinase A has been demonstrated to be involved in the malignant progression of many types of cancer including prostate cancer, we therefore hypothesized that Aurora kinase A might work as a valuable target for prostate cancer treatment. To test this hypothesis, we used DNAzyme technology to inhibit Aurora kinase A expression and evaluated the effects of DNAzymes as therapeutic agents to treat prostate cancer. In an in vitro cleavage assay, we found that a DNAzyme (DZ2) targeting Aurora kinase A could effectively cleave Aurora kinase A mRNA. When transfected into the prostate cancer cell line PC3, DZ2 was found to strongly inhibit the expression of Aurora kinase A examined by western blot analysis, and thus suppressed cell growth, arrested the progression of cell cycle, induced cell apoptosis and attenuated cell migration, as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assay, flow cytometry and Boyden chamber assay. Through in vivo study, we also found that DZ2 could significantly inhibit the growth of human prostate cancer xenografts in nude mice. In conclusion, DZ2 could effectively attenuate malignant progression of prostate cancer both in vitro and in vivo, suggesting that DNAzyme targeting Aurora kinase A may be used as a valuable therapy to treat prostate cancer.

Calcium and survivin are involved in the induction of apoptosis by dihydroartemisinin in human lung cancer SPC-A-1 cells

Dihydroartemisinin (DHA), a semisynthetic derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua, is an effective novel antimalarial drug. Recent studies suggest that it also has anticancer effects. The present study investigated the apoptosis activity of DHA in cultured human lung cancer cells by terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) assay and flow cytometry. Intracellular free calcium concentrations in the lung cancer cells were evaluated by laser scanning confocal microscopy using Fura-3/AM as probe. The observations also indicated that DHA downregulated the mRNA and protein expression level of survivin in the lung cancer cell line SPC-A-1 cells, whereas it did not affect those of caspase-4. These results demonstrated that DHA can induce apoptosis of lung cancer cell line SPC-A-1 cells and that calcium and survivin participated in the apoptotic signalling pathways.

Translocation t(14;18) and gain of chromosome 18/BCL2: effects on BCL2 expression and apoptosis in B-cell non-Hodgkin's lymphomas

Gain of chromosome 18q and translocation t(14;18) are] frequently found in B-cell non-Hodgkin's lymphomas (B-NHL). Increased BCL2 transcription and BCL2 protein expression have been suggested to be the result of the gain. We utilized FISH, PCR and array CGH to study BCL2 and chromosome 18 copy number changes and rearrangements in 93 cases of B-NHL. BCL2 protein was expressed in >75% of the tumor cells in 92% of the cases by immunohistochemistry. Gain of BCL2 was associated with a 25% increase in BCL2 expression levels (immunoblotting), whereas t(14;18) resulted in a 55% increase in BCL2 levels compared to cases without BCL2 alterations. The tumor cell (spontaneous) apoptotic fractions were similar for the cases with different BCL2 genotypes. However, the normal cell apoptotic fractions were higher for the tumors with t(14;18) compared to the tumors without BCL2 alterations, while the tumors with gain of BCL2 only showed intermediate levels. Low-level gains of parts of chromosome 18 were found in 14 of the 38 B-NHL cases with t(14;18), with a consensus region 18pter-q21.33 that did not include the BCL2 gene. The 11 cases with 18q gain only showed a consensus region encompassing 18q21.2-18q21.32 and 18q21.33, which contain PMAIP1/MALT1 and BCL2, respectively.

DNA interstrand cross-links induce futile repair synthesis in mammalian cell extracts

DNA interstrand cross-links are induced by many carcinogens and anticancer drugs. It was previously shown that mammalian DNA excision repair nuclease makes dual incisions 5' to the cross-linked base of a psoralen cross-link, generating a gap of 22 to 28 nucleotides adjacent to the cross-link. We wished to find the fates of the gap and the cross-link in this complex structure under conditions conducive to repair synthesis, using cell extracts from wild-type and cross-linker-sensitive mutant cell lines. We found that the extracts from both types of strains filled in the gap but were severely defective in ligating the resulting nick and incapable of removing the cross-link. The net result was a futile damage-induced DNA synthesis which converted a gap into a nick without removing the damage. In addition, in this study, we showed that the structure-specific endonuclease, the XPF-ERCC1 heterodimer, acted as a 3'-to-5' exonuclease on cross-linked DNA in the presence of RPA. Collectively, these observations shed some light on the cellular processing of DNA cross-links and reveal that cross-links induce a futile DNA synthesis cycle that may constitute a signal for specific cellular responses to cross-linked DNA.

The relationship between the c-jun mRNA expression and apoptosis of neurons in rat brain following perinatal ischemic-hypoxia

OBJECTIVE

To investigate the relationship between c-jun mRNA and apoptosis of neurons following perinatal ischemic-hypoxia.

METHODS

We set up a fetal rat model of perinatal ischemic-hypoxia by ligating unilateral uterine horn vessel of pregnant Wistar rats (21-day gestation). The contralateral horn vessel was not ligated and the fetuses in these uteri served as controls. Rat pups were delivered by cesarean section at the end of ischemic hypoxic insult and then the rats' brain tissues were collected in different points of time. In situ hybridization and TUNEL methods were used to detect the c-jun mRNA expression and neural cells apoptosis separately.

RESULTS

The expression of c-jun mRNA in brain tissues began at 15 minutes, reached the first peak at 1-2 hours after ischemic-hypoxic insult and reduced gradually after 4 hours and the second peak at 24th hour after insult, gradually disappeared till 72nd hour. There were very low c-jun mRNA expression of hippocampus in the control group 24 h after birth. Meanwhile, we observed that the apoptosis of neuronal cells in cerebral cortex was much more than that in the control group.

CONCLUSION

The increases of immediate early gene c-jun expression and the cell apoptosis could be induced by perinatal ischemic-hypoxia. The higher expression of c-jun mRNA might induce the transcription of its target gene, especially, so called "death related genes", which would be a promoter for cell apoptosis.

[Determination of germanium and selenium in malt powder by GFAAS]

A method for determination of germanium and selenium in malt powder has been developed by graphite furnace atomic absorption spectrometry with L'vov platform. While (Pd+Ni) and Pd were used as matrix modifiers,the ashing temperatures of Ge and Se were increased to 1400 and 1200 degrees C respectively,and the matrix inferences were removed. The characteristic masses are 31 pg Ge and 23pg Se(0.0044 A), the detection limits are 28pg Ge and 62pg Se (3 sigma), the precisions (n = 9) are 3. 7-5.6%(Ge) and 4.3-6.5% (Se) and the recoveries are among 90-105%.

(6-4) photolyase: light-dependent repair of DNA damage

DNA photolyase represents a phenomenal class of DNA repair enzymes in that it harvests the light energy to repair DNA lesions caused by ultraviolet light. Mother Nature evolves two types of photolyases, one specific for repairing cyclobutane pyrimidine dimers and the other for pyrimidine-(6-4)-pyrimidone photoproducts. Together, these two kinds of DNA photolesions account for the majority of ultraviolet light-induced DNA lesions. So far, the basic chemical steps of the enzyme mechanism of the two classes of photolyases appear to be very similar. Therefore, it will be very interesting to uncover the determinants of the different substrate specificity between the two photolyases. In this review, we focus on the discussion of the photolyase specific for repairing pyrimidine-(6-4)-pyrimidone photoproducts mainly because the research of the cyclobutane pyrimidine dimer photolyase has recently been reviewed quite extensively.

[The changes of glutamate receptor and free Ca2+i in hypoxic-ischemic cerebral injury: experimental study]

This experiment was designed to explore the pathogenesis in hypoxic-ischemic encephalopathy (HIE). Sixteen newborn pigs were divided into two groups: (Group A) normal control and (Group B) HIE 24 hours. The glutamate receptor (Glu R) in forebrain crude synaptic membrane (SPM) and free Ca2+i in RBC were tested respectively. The results revealed that the binding sites (Bmax) of Glu R in Group B was much lower than that in Group A, but the affinity (Kd) showed no statistic difference between Group A and Group B. In addition, free Ca2+i of RBC in Group B was much higher than that in Group A. This study demonstrates that the changes of Glu R and Ca2+i are involved in the pathogenesis of hypoxic-ischemic cerebral injury in newborn animals.

Initiation of DNA interstrand cross-link repair in humans: the nucleotide excision repair system makes dual incisions 5' to the cross-linked base and removes a 22- to 28-nucleotide-long damage-free strand

Most DNA repair mechanisms rely on the redundant information inherent to the duplex to remove damaged nucleotides and replace them with normal ones, using the complementary strand as a template. Interstrand cross-links pose a unique challenge to the DNA repair machinery because both strands are damaged. To study the repair of interstrand cross-links by mammalian cells, we tested the activities of cell extracts of wild-type or excision repair-defective rodent cell lines and of purified human excision nuclease on a duplex with a site-specific cross-link. We found that in contrast to monoadducts, which are removed by dual incisions bracketing the lesion, the cross-link causes dual incisions, both 5' to the cross-link in one of the two strands. The net result is the generation of a 22- to 28-nucleotide-long gap immediately 5' to the cross-link. This gap may act as a recombinogenic signal to initiate cross-link removal.