Is the prognostic impact of tumor location in patients with surgically resected esophageal squamous cell carcinoma affected by surgical approach?

AIM

The aim of the present study was to clarify differences in node metastasis mode and clinical outcomes based on tumor location in patients with esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Participants comprised 228 patients with ESCC who underwent radical esophagectomy without preoperative supplement therapies. Lymph nodes were harvested from three fields: the neck, thorax, and abdomen. Patients were divided into three groups depending on tumor location [upper esophagus (UE), middle esophagus, or lower esophagus (LE)] and analyzed clinicopathologically.

RESULTS

The LE group showed significantly more progressive ESCC in terms of tumor invasion (p = 0.025), node metastasis (p = 0.0071), and TNM stage (p = 0.0043). The LE group revealed a tendency to metastasize to extrathoracic (especially abdominal) nodes (p = 0.0008). Recurrent laryngeal node metastasis was increased in the UE group (p = 0.016). However, no prognostic differences were detected between groups according to tumor location. Likewise, subgroup analyses by surgical approach (open thoracotomy vs. thoracoscopy) and cancer stage (stage I/II, III, and IV) did not reveal any significant prognostic impact of tumor location.

CONCLUSION

Lymphatic spread varied by tumor location, but no prognostic impact of tumor location could be detected in patients with ESCC in spite of surgical approach or cancer stage.

Effect of temperature on the solubility and solid phase stability of zirconium hydroxide

The solubility and solid phase stability of zirconium hydroxide was investigated in the acidic pH range after heating the aqueous samples at 50, 70 and 90 ◦C. The solubility measured at room temperature after exposing the batch samples to elevated temperatures for a given period of time significantly decreased with increasing heating periods. The Zr concentrations at given pH after heating at 90 ◦C for 3 weeks are about 5 orders of magnitude lower than the solubility of amorphous zirconium hydroxide (Zr(OH)4(am)) kept at room temperature. Size distributions of the Zr colloidal species after heating were investigated by sequential filtration using different pore-sized membranes, and the contribution of the colloidal species to the solubility was assessed. The TEM images and XRD spectra of the solid phases after heating indicated the agglomeration and crystallization of the initial amorphous hydroxide solid phase. The solid phase was identified as crystalline oxide after heating at 90◦C. The solubility product determined from the solubility data excluding contributions of colloidal species is correlated to the particle size of the solid phase.

Can a Belly Board Reduce Respiratory-Induced Prostate Motion in the Prone Position? — Assessed by Cine-Magnetic Resonance Imaging

The purpose of this study is to evaluate the real-time respiratory motion of the prostate and surrounding tissues/organs in the supine and prone positions and to investigate, using cine-MRI, whether a belly board can reduce respiratory-induced motion in the prone position. Cine-MRI scans were made of 13 volunteers in the supine and prone positions on a flat board and in two different prone positions using a belly board. Images in cine mode were recorded for 20 seconds. For each session, the points of interest (POIs) were located at the apex, base, mid-anterior surface and mid-posterior surface of the prostate; the tip of the seminal vesicle; the pubic symphysis; and the sacrum. The maximum range and standard deviation (SD) of the displacement from the mean value were calculated. The SDs for each of the four different positions were compared using a paired t-test. Respiratory-induced prostate motion was significantly larger in the prone position than in the supine position. However, when a belly board was used in the prone position, motion in the prostate and surrounding tissues/organs was significantly reduced. There were no significant differences between the two different positions using a belly board in any of the POIs.

Hypothalamic ATF3 is involved in regulating glucose and energy metabolism in mice

AIMS/HYPOTHESIS

The pancreas and hypothalamus are critical for maintaining nutrient and energy homeostasis, and combined disorders in these organs account for the onset of the metabolic syndrome. Activating transcription factor 3 (ATF3) is an adaptive response transcription factor. The physiological role of ATF3 in the pancreas has been controversial, and its role in the hypothalamus remains unknown. To elucidate the roles of ATF3 in these organs, we generated pancreas- and hypothalamus-specific Atf3 knockout (PHT-Atf3-KO) mice in this study.

METHODS

We crossed mice bearing floxed Atf3 alleles with Pdx1-cre mice, in which cre is specifically expressed in the pancreas and hypothalamus, and analysed metabolic variables, pancreatic morphology, food intake, energy expenditure and sympathetic activity in adipose tissue. We also used a hypothalamic cell line to investigate the molecular mechanism by which ATF3 regulates transcription of the gene encoding agouti-related protein (Agrp).

RESULTS

Although PHT-Atf3-KO mice displayed better glucose tolerance, neither plasma glucagon nor insulin level was altered in these mice. However, these mice exhibited higher insulin sensitivity, which was accompanied by a leaner phenotype due to decreased food intake and increased energy expenditure. We also observed decreased hypothalamic Agrp expression in PHT-Atf3-KO mice. Importantly, an increase in ATF3 levels is induced by fasting or low glucose in the hypothalamus. We also showed that ATF3 interacts with forkhead box-containing protein, O subfamily 1 (FoxO1) on the Agrp promoter and activates Agrp transcription.

CONCLUSIONS/INTERPRETATION

Our results suggest that ATF3 plays an important role in the control of glucose and energy metabolism by regulating Agrp.

Collective excitation of an electric dipole on a molecular dimer in an organic dimer-Mott insulator

The terahertz response in 10-100 cm(-1) was investigated in an organic dimer-Mott (DM) insulator κ-(ET)(2)Cu(2)(CN)(3) that exhibits a relaxorlike dielectric anomaly. An ~30 cm(-1) band in the optical conductivity was attributable to collective excitation of the fluctuating intradimer electric dipoles that are formed by an electron correlation. We succeeded in observing photoinduced enhancement of this ~30 cm(-1) band, reflecting the growth of the electric dipole cluster in the DM phase. Such optical responses in κ-(ET)(2)Cu(2)(CN)(3) reflect an instability near the boundary between the DM-ferroelectric charge ordered phases.

Use of forward genetic screens to identify genes required for RNA-directed DNA methylation in Arabidopsis thaliana

RNA-directed DNA methylation is a small RNA-mediated epigenetic modification that contributes to transcriptional silencing of transposons and repetitive sequences in plants. We have conducted several forward genetic screens to identify factors required for RNA-directed DNA methylation and transcriptional gene silencing in Arabidopsis thaliana. Here, we review the findings from these screens and report on two new mutants, dms12 and dms13, that are defective in Pol V-specific subunits NRPE5 and NRPE9b. Cumulative results from genetic screens performed in our laboratory and those of other investigators have revealed that RNA-directed DNA methylation requires a complex transcriptional machinery comprising a number of plant-specific factors, many of which were functionally uncharacterized before being implicated in this pathway. Future challenges include unraveling the detailed mechanism and full range of functions of RNA-directed DNA methylation.

Effect of inhomogeneity in a patient's body on the accuracy of the pencil beam algorithm in comparison to Monte Carlo

The pencil beam algorithm (PBA) is reasonably accurate and fast. It is, therefore, the primary method used in routine clinical treatment planning for proton radiotherapy; still, it needs to be validated for use in highly inhomogeneous regions. In our investigation of the effect of patient inhomogeneity, PBA was compared with Monte Carlo (MC). A software framework was developed for the MC simulation of radiotherapy based on Geant4. Anatomical sites selected for the comparison were the head/neck, liver, lung and pelvis region. The dose distributions calculated by the two methods in selected examples were compared, as well as a dose volume histogram (DVH) derived from the dose distributions. The comparison of the off-center ratio (OCR) at the iso-center showed good agreement between the PBA and MC, while discrepancies were seen around the distal fall-off regions. While MC showed a fine structure on the OCR in the distal fall-off region, the PBA showed smoother distribution. The fine structures in MC calculation appeared downstream of very low-density regions. Comparison of DVHs showed that most of the target volumes were similarly covered, while some OARs located around the distal region received a higher dose when calculated by MC than the PBA.

The extent of degeneration of cruciate ligament is associated with chondrogenic differentiation in patients with osteoarthritis of the knee

OBJECTIVE

Degeneration in cruciate ligaments results from abnormal biomechanical stress and the aging process. Such degeneration is a common outcome in patients with osteoarthritis (OA) of the knee and contributes to the progression of OA. However, to date, there are no specific markers that can predict the extent of ligament degeneration. We hypothesized that the extent of degeneration has correlations to increased chondrogenic potential.

METHODS

Twenty anterior cruciate ligaments (ACLs) and 30 posterior cruciate ligaments (PCLs) from 30 knees of 28 adult patients with OA at the time of total knee arthroplasty were used for the study. Degeneration was histologically assessed using a grading system. Expressions of Scleraxis (as a ligament cell marker) and Sry-type HMG box 9 (SOX9) (as a chondrogenic marker) were immunohistochemically assessed in each grade.

RESULTS

We found the opposite expression pattern between Scleraxis and SOX9 according to the grade. The percentage of Scleraxis-positive cells decreased significantly by grade (60.9±23.7 in grade 1, 39.7±30.5 in grade 2, and 13.9±27.1 in grade 3, P<0.0001). In contrast, the percentage of SOX9-positive cells increased significantly by grade (2.5±4.9 in grade 1, 17.5±13.4 in grade 2, and 50.9±27.1 in grade 3, P<0.0001). Furthermore, co-localized expression of both Scleraxis and SOX9 was demonstrated in chondrocyte-like cells.

CONCLUSIONS

This study indicates that chondrogenic differentiation is associated with the progression of degeneration in human ligaments. Our results suggest that the expression of SOX9 as a chondrogenic marker could be an indicator for the extent of degeneration in human ligaments. It remains to be elucidated whether suppression of chondrogenic differentiation can prevent progression of the degenerative process of cruciate ligaments in patients with OA.

Antitumor effect of a novel multifunctional antitumor nucleoside, 3'-ethynylcytidine, on human cancers

The antitumor activity of 1-(3-C-ethynyl-beta-D-ribopentofuranosyl) cytosine (ECyd), designed as a potential multifunctional antitumor nucleoside that could be expected to inhibit RNA and DNA syntheses, was examined. ECyd inhibited the growth of 47 kinds of cultured human cells in vitro, and also showed strong antitumor effects on 15 human solid cancers xenografted into nude mice at a dose of 0.25 mg/kg by intravenous administration for 10 consecutive days. The in vitro cytotoxic effect of ECyd was prevented dose dependently by cytidine and uridine, suggesting that ECyd may require phosphorylation by uridine/cytidine kinase for antitumor activity. ECyd strongly inhibited RNA synthesis and also slightly inhibited DNA synthesis. ECyd has shown potent antitumor activity against human experimental solid type tumors with minimal toxic effects in vivo, suggesting that ECyd will be a promising agent with a unique mechanism of action for the treatment of cancer.

Mechanisms of the formation of the peritoneal dissemination in gastric cancer

To clarify the mechanisms of the formation of peritoneal dissemination, a new animal model by the i.p. inoculation of highly metastatic gastric cancer cell line MKN-45-P was developed. Peritoneal dissemination with bloody ascites was found in 100% of nude mice, injected 1x10(7) MKN-45-P cells in suspension into the peritoneal cavity. By a highly sensitive method for specific detection of metastasized human tumor cells in nude mice using polymerase chain reaction, a human beta-globin-related sequence in the DNA from various parts of the peritoneum was specifically amplified and detected by gel electrophoresis and by a specific oligonucleotide probe. Greater omentum showed a strong signal of the amplified fragments of human beta-globin gene from the 1st day and the signals gradually increased. The signals in the gonadal fat, mesentery and ovarium could be weakly detected on the Ist day, transiently decreased on the 3rd day, and then increased from the 7th day. In the diaphragm, and abdominal wall, signals could be detected from the 7th day. In contrast, small intestine and colon did not show any human beta-globin signals. In greater omentum and gonadal fat, cancer cells were selectively detected in the milky spots stained by activated carbon on the 3rd day. In the diaphragm, cancer cells adhered to the small pores termed stomata, and invaded into the subdiaphragmatic lymphatic lacunae connected with stomata. From the 3rd day, mesothelial cells of the abdominal cavity became round and separated, resulting in the exposure of the underlying connective tissue. MKN-45-P cells were found to adhere to the naked areas of the submesothelial connective tissue. From these results, we conclude that the major metastatic route of the peritoneum may be firstly through milky spots, secondly through the diaphragmatic stomata, and thirdly by the adhesion to the naked connective tissue exposed after shrinkage of the mesothelial cells. The third process may be related to the interaction between some adhesion molecules and their ligands.

Enhanced tumorigenic and metastatic potential of an androgen-sensitive human prostate cancer cell line, LNCaP, by intratesticular inoculation in SCID mice

To establish a prostate cancer model expressing prostate-specific antigen (PSA) with metastatic potential, LNCaP or PC-3 cells were inoculated into the testis of SCID mice, resulting in a 100% rate of tumor formation. A significant increase in serum PSA was found in mice with LNCaP xenografts. Circulating tumor cells and micrometastases to organs such as lung, liver, spleen, and omentum were detected for both cell lines by PCR of the human beta-globin gene. Lymph node metastases occurred more frequently with PC-3 than LNCaP cells. This is the first report showing stable growth of LNCaP cells in mice with metastases to the regional lymph nodes. This model of prostate cancer should help to assess treatment strategies targeting PSA.

E-cadherin and c-met expression as a prognostic factor in gastric cancer

E-cadherin has an important role in the cell-cell adhesion and is known as an invasion suppressor gene. The c-met, which is a receptor of hepatocyte growth factor receptor, is involved in the proliferative and motile activity in cancer cells. The invasive and metastatic capacities of gastric cancer were studied from the immunohistochemically examined expression of MET and E-cadherin. Among 127 primary gastric cancers, 47 (34%) tumors were found to have preserved E-cadherin expression and the other 84 tumors showed reduced E-cadherin expression. MET expression was found in 55 (43%) tumors. A strong correlation was found between reduced E-cadherin expression and a larger tumor, positive serosal invasion, lymph node metastases or poor prognosis. Tumors with MET expression have the tendencies to invade deeply, to metastasize in more remote lymph nodes or peritoneum and to run a poor prognosis. MET over-expression and reduced E-cadherin expression were strongly associated with lymph node metastasis, peritoneal dissemination and poor prognosis. This group of patients with simultaneously abnormal expressions of these genes had a sixfold relative risk of death, as compared with patients with tumors showing MET negative or preserved E-cadherin expression. These results indicate that immunohistochemical combined analyses of MET and E-cadherin expression may be a powerful tool for the evaluation of invasive capacity and the prognosis of gastric cancer patients.

Comparison off genetic distance and order off DNA markers in five populations of rice

A group of about 300 evenly distributed DNA markers from a high density RFLP linkage map of rice constructed using an F2 population derived from a japonica variety, Nipponbare, and an indica variety, Kasalath, were used to evaluate gene order and genetic distance in four other rice mapping populations. The purpose of this study was to determine the degree to which information gained from the high density linkage map could be applied to other mapping populations, particularly with regard to its utility in bridging quantitative traits and molecular and physical mapping information. The mapping populations consisted of two F2 populations derived from Dao Ren Qiao/Fl-1084 and Kinandangputi/Fl-1007, recombinant inbred lines from Asominori/IR24, and a backcross population from Sasanishiki/Habataki//Sasanishiki. All DNA markers commonly mapped in the four populations showed the same linkage groups as in the Nipponbare/Kasalath linkage map with conserved linkage order. The genetic distance between markers among the different populations did not vary to a significant level in any of the 12 chromosomes. The differences in some markers could be attributed to the size of the population used in the construction of the linkage maps. Furthermore, the conservation of linkage order found in the distal region of chromosomes 11 and 12 was also confirmed in the RFLP maps based on the four populations of rice. These suggest that any major genetic information from the Nipponbare/Kasalath map can be expected to be approximately the same in other crosses or populations. This high density RFLP linkage map, which is being utilized in constructing a physical map of rice, can be very useful in interpreting genome structure with great accuracy in other populations. Key words : linkage map, japonica, indica, gene order, genetic distance.