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Recurrence-free survival and 5-year survival rates are still commonly used as prognostic indicators for gastrointestinal cancer. We believe that there is a need to find an appropriate index to evaluate changes in health status over time in postoperative patients. We evaluated changes in "frailty" after esophageal cancer surgery using the Kihon Checklist (KCL) developed by the Japanese Ministry of Health, Labour and Welfare, and examined risk factors for worsening health status after surgery. Twenty-four patients (21 thoracoscopic sub-total esophagectomy, 1 mediastinoscopic sub-total esophagectomy, and 2 total laryngopharyngoesophagectomy) who underwent esophageal cancer surgery in our department from December 2019 to April 2021 were included. Patients were asked to write down their KCL before surgery and one year after surgery at an outpatient clinic, and changes over time were checked. We compared the background factors in the "maintain" group (M group) and the "worsened" group (W group), and investigated the risk factors for pre-frail and frail states one year after the surgery. 8 patients worsened from robust to pre-frail to frail and pre-frail to frail, and 16 patients maintained their condition, with 33% of them worsening. Age (M/W: 70/72, p=0.296), male (M/W: 0.88/1.0, p=0.536), BMI (M/W: 22.4/19.6, p=0.142), pStage≥3 (M/W: 0.38/0.38, p=1.0), preoperative chemotherapy (M/W: 0.69/0.63, p=1.0), operative time (M/W: 566/610 minutes, p=0.327), blood loss (M/W: 103/151 ml, p=0.342), postoperative pneumonia (M/W: 0.25/0.25, p=1.0), and cancer recurrence (M/W: 0.19/0.50, p=0.167). The preoperative blood samples were Alb (M/W: 4.3/3.8 g/dl, p=0.046), Hb (M/W: 14.2/12.8 g/dl, p=0.015) and Cre (M/W: 0.85/0.79 mg/dl, p=0.713). At 1 year after esophageal cancer surgery, health worsened and 33% of patients were in a pre-frail or frail state. Risk factors for worsening health were low Alb and low Hb, which were not related to stage or actual age. Further study is needed to clarify risk factors for frailty.

SUMMARY. Radiotherapy plays a key role in the control of tumor growth in esophageal cancer patients. To identify the patients who will benefit most from radiation therapy, it is important to know the genes that are involved in the radiosensitivity of esophageal cancer cells. Hence, we examined the global gene expression in radiosensitive and radioresistant esophageal squamous cell carcinoma cell lines. Radiosensitivities of 13 esophageal cancer cell lines were measured. RNA was extracted from each esophageal cancer cell line and a normal esophageal epithelial cell line, and the global gene expression profiles were analyzed using a 34 594-spot oligonucleotide microarray. In the clonogenic assay, one cell line (TE-11) was identified to be highly sensitive to radiation, while the other cell lines were found to be relatively radioresistant. We identified 71 candidate genes that were differentially expressed in TE-11 by microarray analysis. The up-regulated genes included CABPR, FABP5, DSC2, GPX2, NME, CBR3, DOCK8, and ABCC5, while the down-regulated genes included RPA1, LDOC1, NDN, and SKP1A. Our investigation provided comprehensive information on genes related to radiosensitivity of esophageal cancer cells; this information can serve as a basis for further functional studies.

SUMMARY. NDRG1 (N-myc downstream regulated gene-1) was reported to be necessary for p53-mediated apoptosis and to be regulated by PTEN (phosphatase and tensin homolog). In several cancers, it was suggested to be a tumor suppressor gene. Its significance in esophageal squamous cell carcinoma (ESCC) has not been studied. The objective of this study was to clarify the relation between clinicopathological and biologic factors in esophageal carcinoma and to determine the prognostic significance of the expression of NDRG1. Expression of NDRG1 mRNA was quantified by real-time reverse transcription polymerase chain reaction using a Lightcycler in 47 esophageal ESCC specimens. The data were analyzed with reference to clinicopathological factors. Among the esophageal cancer tissues, NDRG1 mRNA expression was significantly lower in tumors of more advanced pathological stage (0–I vs. II–IV; P = 0.0027) and local tumor invasion (T1–2 vs. T3–4; P = 0.0136). Patients who had low NDRG1 mRNA expression had a significantly shorter survival after surgery compared with patients who had high NDRG1 mRNA expression (log-rank test, P = 0.0478). Impaired NDRG1 expression may lead to more aggressive invasion of ESCC.

Transcription from the human immunodeficiency virus type 1 (HIV-1) provirus is activated by a cellular factor, NF kappa B, recognizing the tandemly repeated 10-base-pair sequences, termed the kappa B sequence, present in the enhancer region within the viral long terminal repeat (LTR). Using electrophoretic mobility shift assay (EMSA), which demonstrates specific DNA-protein interaction in vitro, we could demonstrate that reducto-oxidative modulation of NF kappa B dramatically changes its DNA binding activity and that a cellular physiological reducing catalyst, thioredoxin (TRX) also known as adult T cell leukemia derived factor (ADF), fully restored the DNA-binding activity of the oxidized NF kappa B. We also observed that purified TRX/ADF protein could augment gene expression from HIV LTR as demonstrated by transient chloramphenicol acetyltransferase (CAT) assay. These observations confirmed the previous notion that ADF might be an inducing factor of cellular interleukin-2 receptor alpha subunit (IL-2R alpha) through the kappa B sequence that is a common central cis-regulatory element in both IL-2R alpha and HIV gene expression. These observations indicate that reducto-oxidative regulation (or redox regulation) of a cysteine residue(s) on the NF kappa B molecule might play an important role in its specific DNA interaction and that it might provide a clue to the understanding of a pathway of cellular signal transduction to NF kappa B that is independent from the known pathways involving protein phosphorylation.

In vitro formation of the 35S-labeled Fe-S cluster of ferredoxin (Fd) has been achieved by incubating apo-Fd and [35S]cysteine with osmotically lysed chloroplasts of spinach (Spinacia oleracea). Correct integration of the 35S-labeled Fe-S cluster into Fd was verified on the basis of the following: (a) Under nondenaturing conditions, 35S-labeled holo-Fd showed the same electrophoretic mobility as authentic holo-Fd; (b) 35S-labeled holo-Fd showed an ability to bind Fd-NADP+ reductase; (c) the 35S-labeled moiety was removed from the Fd polypeptide by TCA treatment but not by 2-mercaptoethanol treatment; (d) externally added pea II apo-Fd was converted to 35S-labeled holo-Fd. This reconstitution was dependent on both ATP and light, and formation of the 35S-labeled Fe-S cluster was observed upon addition of ATP or when an ATP generation-system was constructed in the light. In contrast, ATP-consuming systems abolished the Fe-S cluster formation. A non-hydrolyzable ATP analog was unable to serve as an ATP substitute, indicating the requirement of ATP hydrolysis for cluster formation. GTP was able to substitute for ATP, but CTP and UTP were less effective. Fe-S cluster formation in lysed chloroplasts was stimulated by light even in the presence of added ATP. Light stimulation was inhibited by DCMU or methyl viologen but not by NH4+. NADPH was able to substitute for light, indicating that light energy is required for the production of reducing compounds such as NADPH in addition to the generation of ATP. These results confirm the requirement of light for the Fe-S cluster formation observed previously in intact chloroplasts.

Ferredoxin (Fd) in higher plants is encoded by a nuclear gene, synthesized in the cytoplasm as a larger precursor, and imported into the chloroplast, where it is proteolytically processed, and assembled with the [2Fe-2S] cluster. The final step in the biosynthetic pathway of Fd can be analyzed by a reconstitution system composed of isolated chloroplasts and [(35)S]cysteine, in which [(35)S]sulfide and iron are incorporated into Fd to build up the (35)S-labeled Fe-S cluster. Although a lysed chloroplast system shows obligate requirements for ATP and NADPH, in vitro chemical reconstitution of the Fe-S cluster is generally thought to be energy-independent. The present study investigated whether ATP and NADPH in the chloroplast system of spinach (Spinacia oleracea) are involved in the supply of [(35)S]sulfide or iron, or in Fe-S cluster formation itself. [(35)S]Sulfide was liberated from [(35)S] cysteine in an NADPH-dependent manner, whereas ATP was not necessary for this process. This desulfhydration of [(35)S]cysteine occurred before the formation of the (35)S-labeled Fe-S cluster, and the amount of radioactivity in [(35)S]sulfide was greater than that in (35)S-labeled holo-Fd by a factor of more than 20. Addition of nonradioactive sulfide (Na(2)S) inhibited competitively formation of the (35)S-labeled Fe-S cluster along with the addition of nonradioactive cysteine, indicating that some of the inorganic sulfide released from cysteine is incorporated into the Fe-S cluster of Fd. ATP hydrolysis was not involved in the production of inorganic sulfide or in the supply of iron for assembly into the Fe-S cluster. However, ATP-dependent Fe-S cluster formation was observed even in the presence of sufficient amounts of [(35)S]sulfide and iron. These results suggest a novel type of ATP-dependent in vivo Fe-S cluster formation that is distinct from in vitro chemical reconstitution. The implications of these results for the possible mechanisms of ATP-dependent Fe-S cluster formation are discussed.