Synergistic growth inhibition by acyclic retinoid and vitamin K2 in human hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most prevalent cancers worldwide. However, effective chemopreventive and chemotherapeutic agents for this cancer have not yet been developed. In clinical trials acyclic retinoid (ACR) and vitamin K(2) (VK(2)) decreased the recurrence rate of HCC. In the present study we examined the possible combined effects of ACR or another retinoid 9-cis retinoic acid (9cRA) plus VK(2) in the HuH7 human HCC cell line. We found that the combination of 1.0 microM ACR or 1.0 microM 9cRA plus 10 microM VK(2) synergistically inhibited the growth of HuH7 cells without affecting the growth of Hc normal human hepatocytes. The combined treatment with ACR plus VK(2) also acted synergistically to induce apoptosis in HuH7 cells. Treatment with VK(2) alone inhibited phosphorylation of the retinoid X receptor (RXR)alpha protein, which is regarded as a critical factor for liver carcinogenesis, through inhibition of Ras activation and extracellular signal-regulated kinase phosphorylation. Moreover, the inhibition of RXRalpha phosphorylation by VK(2) was enhanced when the cells were cotreated with ACR. The combination of retinoids plus VK(2) markedly increased both the retinoic acid receptor responsive element and retinoid X receptor responsive element promoter activities in HuH7 cells. Our results suggest that retinoids (especially ACR) and VK(2) cooperatively inhibit activation of the Ras/MAPK signaling pathway, subsequently inhibiting the phosphorylation of RXRalpha and the growth of HCC cells. This combination might therefore be effective for the chemoprevention and chemotherapy of HCC.     

Simultaneous inhibition of the mitogen-activated protein kinase kinase and phosphatidylinositol 3'-kinase pathways enhances sensitivity to paclitaxel in ovarian carcinoma

Paclitaxel (PTX), one of the key drugs used to treat ovarian cancer, activates the Raf–mitogen-activated protein kinase kinase (MEK) and phosphatidylinositol 3'-kinase (PI3K) pathways, both considered to be proliferation and cell-survival pathways. The present study aimed to clarify whether and how MEK and PI3K inhibitors affect sensitivity to PTX in ovarian cancer cells. We treated five ovarian cancer cell lines using PTX combined with MEK inhibitor (PD98059 [PD]) and PI3K inhibitor (LY294002 [LY]), then assessed cell viability, apoptosis, and expression of phosphorylated (p) MEK and pAkt. We also investigated the effect of combined treatment on survival in a xenograft model. The protein expression levels of MEK, pMEK, Akt, and pAkt were confirmed in all cell lines. pMEK levels increased after PTX treatment in all five ovarian cancer cell lines. Combining PTX with either PD or LY had an additive effect on cell-growth inhibition. In contrast, we observed a synergistic effect when PTX was combined with both PD and LY. The number of apoptotic cells was significantly higher after treatment with PTX combined with PD and LY, compared with PTX alone or PTX with either PD or LY ( P <  0.05). PD with PTX downregulated the protein expression level of pMEK and upregulated pAkt in all five cell lines. Treating nude mice with PTX and PD and LY prolonged survival in an ovarian cancer xenograft model ( P <  0.005). These results indicate that further study is warranted for PTX combined with MEK inhibitor and PI3K inhibitor to treat ovarian carcinoma. ( Cancer Sci 2007; 98: 2002–2008)     

Epididymal sperm motion as a parameter of male reproductive toxicity: sperm motion, fertility, and histopathology in ethinylestradiol-treated rats.

The present study was designed to characterize the effect of ethinylestradiol (EE) on epididymal sperm motion using a computer-assisted sperm analysis system (CASA), and to elucidate the correlation between sperm motion endpoints and other measures including fertility, histopathologic, and endocrinologic endpoints. EE was orally given to adult male rats at a daily dosage of 10 mg/kg for 3 and 5 d, and at daily dosages of I and 10 mg/kg for 1, 2, 3, and 4 weeks. Changes in sperm motion were first detected after one week of treatment. Of nine sperm motion parameters, the percentage of motile sperm, velocity, and amplitude of the lateral head displacement (ALH) were decreased in the 10 mg/kg dosing group. Accompanying the decreases in those parameters, the male fertility indices in the 10 mg/kg dosing group were reduced after one week of treatment, and no males in this group could impregnate intact females after 2 weeks or more of treatment. The number of sperm heads in the cauda epididymis in the 10 mg/kg dosing group was reduced to about one-half that in the control group after one week of treatment, whereas the total number of homogenization-resistant advanced spermatids in the testis was not altered and only a slight change was detected in the number and morphology of germ cells in the testis. These results suggest that reduction in the number of epididymal sperm and in sperm motion are not secondary to testicular alteration. However, after 3 weeks of treatment, the number of sperm heads in the testis was drastically reduced with severe atrophy of the seminiferous tubules both in the 1 and 10 mg/kg dosing groups. The profiling of epididymal luminal fluid proteins indicated that two major bands that migrated with molecular weights of about 22 and 23 kDa were weakened and their density was reduced to approximately 70% of the control after 5-d and one week treatments in the 10 mg/kg dosing group. Circulating testosterone declined drastically after 3 d of treatment and remained at undetectable levels with a concomitant decline of circulating LH and FSH, suggesting that EE inhibits testosterone secretion immediately via a negative feedback system, and there follow changes in the accessory reproductive organs including the epididymis. These results indicate that EE affects epididymal spermatozoa before testicular germ cells via a testosterone deficiency, when it is administered at extremely high dosages. The reduction in the sperm motion manifested as decreases in the percentage of motile sperm, ALH, and velocity, is considered to be responsible for the onset of infertility. Sperm motion analysis could be particularly useful for detecting the toxic effects of chemicals that act through the endocrinologic system on the epididymis.     

Minimally invasive and simultaneous removal of herniated intracanal and extracanal lumbar nucleus pulposus with a percutaneous spinal endoscope

Herniated nucleus pulposus (HNP) in the lumbar spine is usually found in the neural canal (in the intracanal space) and occasionally in the extracanal space, where it is known as a lateral HNP. HNP is rarely found simultaneously in both spaces. However, we experienced such a case in a 48‐year‐old man who presented with right leg pain and lower back pain that had lasted for more than a year. MRI revealed HNP in both the right intracanal and extracanal spaces at L2‐L3. A transforaminal approach was used to complete a percutaneous endoscopic discectomy. An 8‐mm incision was made with the patient under local anesthesia, and the percutaneous endoscope was inserted at the affected disc space. First, the HNP fragments in the intracanal space were removed, and then the cannula and endoscope were extracted to the extracanal space where the extracanal fragments were removed. Two hours after the surgery, the patient stood and walked. Right leg pain and lower back pain had disappeared. Unlike other techniques such as Love's procedure and the microendoscopic discectomy technique, the use of a transforaminal approach with the percutaneous endoscopic technique enables the HNP fragments in the intracanal and extracanal spaces to be removed at the same time with a single approach.     

Infant Mortality Rates for Farming and Unemployed Households in the Japanese Prefectures: An Ecological Time Trend Analysis, 1999–2017

BackgroundRecent research suggests that Japanese inter-prefecture inequality in the risk of death before reaching 5 years old has increased since the 2000s. Despite this, there have been no studies examining recent trends in inequality in the infant mortality rate (IMR) with associated socioeconomic characteristics. This study specifically focused on household occupation, environment, and support systems for perinatal parents.MethodsUsing national vital statistics by household occupation aggregated in 47 prefectures from 1999 through 2017, we conducted multilevel negative binomial regression analysis to evaluate occupation/IMR associations and joinpoint analysis to observe temporal trends. We also created thematic maps to depict the geographical distribution of the IMR.ResultsCompared to the most privileged occupations (ie, type II regular workers; including employees in companies with over 100 employees), IMR ratios were 1.26 for type I regular workers (including employees in companies with less than 100 employees), 1.41 for the self-employed, 1.96 for those engaged in farming, and 6.48 for unemployed workers. The IMR ratio among farming households was 1.75 in the prefectures with the highest population density (vs the lowest) and 1.41 in prefectures with the highest number of farming households per 100 households (vs the lowest). Joinpoint regression showed a yearly monotonic increase in the differences and ratios of IMRs among farming households compared to type II regular worker households. For unemployed workers, differences in IMRs increased sharply from 2009 while ratios increased from 2012.ConclusionsInter-occupational IMR inequality increased from 1999 through 2017 in Japan. Further studies using individual-level data are warranted to better understand the mechanisms that contributed to this increase.Key words: infant mortality, health inequality, occupation, farmer, unemployed worker     

Pattern of lymph node metastases of esophageal squamous cell carcinoma based on the anatomical lymphatic drainage system

The recent anatomical studies of the esophagus showed that submucosal longitudinal lymphatic vessels connect to the superior mediastinal and the paracardial lymphatics and lymphatic routes to periesophageal nodes originate from the muscle layer. Using clinical data for lymph node metastasis, we verify these anatomical bases to clarify the rational areas of lymph node dissection in esophageal cancer surgery. Analysis was performed on 356 consecutive patients who underwent esophagectomy with three‐field dissection. Patients were divided into those with tumor limited within the submucosal layer and those with tumor invading or penetrating the muscle layer. Frequency of node metastasis was compared according to supraclavicular, upper mediastinum, mid‐mediastinum, lower mediastinum, perigastric and celiac areas. In patients with tumor limited to the submucosal layer, node metastasis was more frequent in the upper mediastinum and perigastric area than the mid‐ or lower mediastinum. Even in patients with tumor located in the lower esophagus, node metastasis was more frequent in the upper mediastinum than the mid‐mediastinum or lower mediastinum. In patients with tumor located in the mid‐esophagus, node metastasis was more frequent in the supraclavicular area than the mid‐mediastinum or lower mediastinum. In patients with tumor invading or penetrating the muscle layer, node metastasis in the mid‐ and lower mediastinum increased dramatically, but was still less frequent than those in the upper mediastinum or the perigastric area. Postoperative survival curves did not differ among the involved areas. The most predictive factor associated with lymph node metastasis for postoperative survival was not the area of involved nodes, but the number of involved nodes by multivariate analyses. These clinical results verify recent anatomical observations. The lack of difference in survival rates among the involved areas suggests that these areas should be staged equivalently. For adequate nodal staging, the upper mediastinum should be dissected for the lower esophageal tumor and supraclavicular areas should be dissected for the mid‐esophageal tumor even in patients with tumor limited to within the submucosal layer.