Selective interference of mTORC1/RAPTOR protects against human disc cellular apoptosis, senescence, and extracellular matrix catabolism with Akt and autophagy induction

OBJECTIVE

The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that integrates nutrients to execute cell growth and protein synthesis. We hypothesized that mTOR is essential for the intervertebral disc, the largest avascular, low-nutrient organ. Our objective was to elucidate roles of mTOR signaling in human disc cells.

DESIGN

The mTOR exists in two complexes: mTORC1 containing the regulatory-associated protein of mTOR (RAPTOR) and mTORC2 containing the rapamycin-insensitive companion of mTOR (RICTOR). To analyze their functions in human disc nucleus pulposus cells, RNA interference (RNAi) of mTOR targeting mTORC1 and mTORC2, RAPTOR targeting mTORC1, or RICTOR targeting mTORC2 or rapamycin, a pharmacological mTORC1 inhibitor, was applied. First, mTOR signaling including Akt, p70/ribosomal S6 kinase (p70/S6K), and autophagy were assessed. Then, apoptosis, senescence, and matrix metabolism were evaluated under pro-inflammatory interleukin-1 beta (IL-1β) stimulation.

RESULTS

Western blotting showed significant decreases in specific proteins by each RNAi (all P < 0.0001). In mTOR signaling, RNAi of mTOR and RICTOR decreased p70/S6K and Akt phosphorylation, whereas RAPTOR RNAi decreased p70/S6K but increased Akt phosphorylation. All RNAi treatments increased light chain 3 (LC3)-II and decreased p62/sequestosome 1 (p62/SQSTM1), indicating enhanced autophagy. In apoptosis, IL-1β-induced terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells and poly (ADP-ribose) polymerase (PARP) and caspase-9 cleavage decreased by RAPTOR RNAi. In senescence, IL-1β-induced senescence-associated beta-galactosidase (SA-β-gal)-positive cells and p16/INK4A expression also decreased by RAPTOR RNAi. In matrix metabolism, RAPTOR RNAi reduced IL-1β-induced catabolic matrix metalloproteinase (MMP) release and activation and up-regulated anabolic gene expression. These findings were all consistent with rapamycin administration. Additional disc-tissue analysis detected expression and phosphorylation of mTOR-signaling molecules in varying ages.

CONCLUSION

Selective interference of mTORC1/RAPTOR protects against inflammation-induced apoptosis, senescence, and matrix catabolism possibly through Akt and autophagy induction in human disc cells.

[A Case of Retroperitoneal Abscess Due to Acute Appendicitis during Neo-Adjuvant Chemotherapy for Breast Cancer]

When acute appendicitis occurs in patients treated with chemotherapy, neutropenia and abdominal complaints caused by chemotherapy can contribute to the diagnostic difficulty, masking the increase in white blood cell(WBC)counts and physical findings of acute appendicitis. A 43-year-old premenopausal woman who was diagnosed with stage IIIA left breast cancer was scheduled for neoadjuvant chemotherapy includingfluorouracil plus epirubicin plus cyclophosphamide(FEC), followed by docetaxel and trastuzumab(DOC plus HER). The patient developed fever and lower abdominal pain on day 17 of DOC plus HER cycle 1, and was diagnosed with acute gastroenteritis in the emergency room. These symptoms were almost improved 4 days later, and then cycle 2 was performed as scheduled. WBC counts decreased to 1,530 cells/mL due to DOCinduced myelosuppression on day 8 of cycle 2 when the patient developed lower abdominal pain again. However, WBC counts increased to 21,680 cells/mL on day 13 of cycle 2. Computed tomography scans revealed an intraperitoneal abscess due to acute appendicitis, and consequently urgent operation was performed. It is necessary to understand that patients with acute appendicitis duringchemotherapy can present less clinical findings.

A Case of Adenomyoepithelioma of the Breast Showing Strong Uptake of 18 F-Fluorodeoxyglucose on a Positron Emission Tomography

An adenomyoepithelioma of the breast is a rare tumor characterized by biphasic proliferation of both epithelial and myoepithelial cells. This tumor is generally considered as a benign neoplasm, and there are few reports describing the imaging features of this tumor through ¹⁸ F-fluorodeoxyglucose positron emission tomography (FDG-PET). Here, we report a case of an adenomyoepithelioma that showed strong uptake of FDG on PET similar to that observed with a malignant tumor. A 73-year-old woman presented to our hospital with a 3.5-cm, mobile, and elastic hard tumor in the upper area of the left breast. Although the findings of mammography, ultrasonography, and contrast-enhanced magnetic resonance imaging suggested that the tumor was malignant, it was diagnosed as an adenomyoepithelioma by core needle biopsy. An invasive ductal carcinoma, 0.5-cm in size, was detected in the medial upper area of the ipsilateral breast during an examination. Although FDG-PET demonstrated no lymph node or distant metastases from the invasive ductal carcinoma, strong uptake of FDG was detected in the adenomyoepithelioma. Breast conserving surgery and sentinel lymph node biopsy for the invasive ductal carcinoma together with resection of the adenomyoepithelioma was performed. A diagnosis of adenomyoepithelioma was confirmed through histologic examination of the resected specimen. This case indicates that some adenomyoepitheliomas may show a strong uptake of FDG on PET, which resembles a malignant tumor.

Human 3β-hydroxysteroid dehydrogenase type 1 in human breast cancer: clinical significance and prognostic associations

Active sex steroids including estrogens and androgens are locally produced from circulating inactive steroids by various steroid-metabolizing enzymes, and play pivotal roles in the progression of hormone-dependent breast cancers. Human 3β-hydroxysteroid dehydrogenase type 1 (3β-HSD type 1) is a critical enzyme in the formation of all classes of active steroid hormones, and is also involved in the inactivation of potent androgen dihydrotestosterone (DHT). Therefore, this enzyme is suggested to modulate active sex steroid production or inactivation, with a role in hormone-dependent breast cancer. The purpose of this study was to investigate the clinical significance of 3β-HSD type 1 in human breast cancer. Using immunohistochemistry (IHC), we evaluated 3β-HSD type 1 expression in 161 human breast cancers and analyzed correlations of 3β-HSD type 1 expression with various clinicopathological factors. Of 161 breast cancer cases, 3β-HSD type 1 expression in cancer cells was detected in 119 cases (73.9%), and was positively correlated with estrogen receptor (ER)-positivity but not HER-2 status. In ER-positive cases (n = 130), 3β-HSD type 1 expression was inversely correlated with invasive tumor size (P = 0.0009), presence of invasive region (P = 0.0107), and lymphatic involvement (P = 0.0004). 3β-HSD type 1 expression was significantly associated with decreased risk of recurrence or improved prognosis by both univariate (P = 0.0003 and P = 0.009, respectively) and multivariate (P = 0.027 and P = 0.023, respectively) analyses. Our findings indicate that this enzyme is a prognostic factor in hormone-dependent breast cancer.

Lipid-rich carcinoma of the breast that is strongly positive for estrogen receptor: a case report and literature review

Lipid-rich carcinoma (LRC) of the breast is a rare breast cancer variant that accounts for <1% of all breast malignancies. It has been reported that LRCs are negative for estrogen receptor. Here, we report a case of LRC of the breast that was strongly positive for estrogen receptor and treated with endocrine adjuvant therapy. A 52-year-old postmenopausal female noticed a lump in her right breast by self-examination and presented to our hospital. Physical examination revealed an elastic 30 mm ×20 mm hard mass in the upper medial part of her right breast. The findings obtained using ultrasonography, mammography, and contrast-enhanced magnetic resonance imaging suggested breast cancer. Core needle biopsy resulted in the diagnosis of invasive carcinoma. The patient underwent mastectomy and sentinel lymph node biopsy. Histopathologically, the tumor cells were abundant in foamy cytoplasm. Because the presence of marked cytoplasmic lipid droplets was confirmed by Sudan IV staining and electron microscopic examination of the tumor and the lipid droplets were negative for periodic acid-Schiff staining, the tumor was diagnosed as an LRC. Immunohistochemically, estrogen and progesterone receptors of the tumor were strongly positive, human epidermal growth factor receptor type 2 was negative, and the ratio of Ki-67-positive cells was ~30%. After surgery, the patient underwent combination chemotherapy with anthracycline, cyclophosphamide, and 5-fluorouracil, followed by docetaxel. Thereafter, the pateint was treated with letrozole and has remained well for 24 months with no signs of recurrence.

Breast metastases of gastric signet-ring cell carcinoma: a report of two cases and review of the literature

It is occasionally difficult to diagnose breast metastasis of gastric carcinoma because of its rarity. However, to appropriately treat patients with breast tumors without delay, it is important to distinguish metastatic cancer from primary breast cancer. We report two cases of breast metastasis of gastric carcinoma and review the literature. The first case was a 41-year-old female diagnosed with bilateral pelvic tumors who visited the outpatient clinic because of pain and enlargement of both breasts. Ultrasonography showed diffuse hypoechoic lesions, which were enhanced on gadolinium-enhanced magnetic resonance imaging in the bilateral mammary gland. Core needle biopsy of the right breast revealed signet-ring cells, which were also identified in the resected bilateral pelvic tumors. Subsequent upper gastrointestinal endoscopy revealed signet-ring cell carcinoma in the stomach, and the bilateral breast lesions were diagnosed as metastases of gastric carcinoma. The second case was a 34-year-old female diagnosed with cervical metastasis of signet-ring cell carcinoma who was referred to the breast cancer clinic because of a nodule in the left breast detected by computed tomography. Ultrasonography showed a hypoechoic nodule that was enhanced on gadolinium-enhanced magnetic resonance imaging. Because the pathologic findings for the left breast nodule were quite similar to those of gastric cancer and its cervical metastasis, the breast nodule was diagnosed as a metastasis of gastric carcinoma. When a breast tumor is suspected to have metastasized from a primary tumor in another organ, particularly if signet-ring cells are found, the possibility that gastric cancer is present should be considered.

A phase I/II trial of irinotecan plus amrubicin supported with G-CSF for extended small-cell lung cancer

OBJECTIVE

This study reports the findings of a Phase I/II, cohort, dose-escalation trial of amrubicin and irinotecan with the support of granulocyte colony-stimulation factor. This study aimed to determine the dose-limiting toxicity of the combination and to define the maximum-tolerated dose, as a recommended dose for Phase II trials. We also sought to obtain preliminary data on the efficacy of this combination as a frontline therapy for extensive-disease small-cell lung cancer.

METHODS

We included 23 chemo-naïve patients with extensive-disease small-cell lung cancer in the trial. The amrubicin dose was escalated from 35 to 40 mg/m(2) (Levels 1 and 2, respectively) to determine the dose-limiting toxicity, with an unchanged dose of irinotecan at 50 mg/m(2).

RESULTS

Of nine patients, three experienced dose-limiting toxicities at Level 1 of prolonged Grade 4 neutropenia, Grade 3 febrile neutropenia and Grade 3 febrile neutropenia with Grade 3 diarrhea. At Level 2, two patients experienced dose-limiting toxicities of Grade 4 neutropenia and Grade 3 neutropenia with Grade 4 diarrhea. The maximum-tolerated doses and recommended doses for amrubicin and irinotecan were therefore determined to be 35 and 50 mg/m(2), respectively. The Level 1 trial was then expanded to 21 patients, 14 (70%) of whom showed partial responses to the recommended dose. The median progression-free and overall survival times were 6.37 and 15.21 months, respectively.

CONCLUSIONS

The combination of amrubicin and irinotecan with the support of granulocyte colony-stimulation factor produced a potent effect in chemo-naïve extensive-disease small-cell lung cancer patients. The use of biomarkers for this regimen may identify patients who are likely to suffer from treatment-ending severe adverse effects.

Rapid tumor necrosis and massive hemorrhage induced by bevacizumab and paclitaxel combination therapy in a case of advanced breast cancer

Bevacizumab when combined with chemotherapy exerts significant activity against many solid tumors through tumor angiogenesis inhibition; however, it can induce severe side effects. We report the rare case of a 27-year-old premenopausal woman with locally advanced breast cancer that was marked by rapid tumor necrosis followed by massive hemorrhage shortly after bevacizumab and paclitaxel administration. On the basis of histopathological examination of a biopsy specimen and computed tomography findings, she was diagnosed with stage IV estrogen and progesterone receptor-negative and human epidermal growth factor receptor type 2-positive breast cancer with multiple organ metastases when she had entered gestational week 24. Cyclophosphamide, Adriamycin®, fluorouracil therapy was initiated, but multiple liver metastases continued to progress. A healthy fetus was delivered by induced delivery and trastuzumab-based treatment was initiated. Although the multiple liver metastases were controlled successfully by trastuzumab combined with paclitaxel, the primary tumor continued to expand even after subsequent administration of three other treatment regimens including anti-human epidermal growth factor receptor type 2 agents and cytotoxic drugs. To inhibit primary tumor growth, a combination therapy with paclitaxel and bevacizumab was subsequently initiated. Following therapy initiation, however, the large tumor occupying the patient’s entire left breast became necrotic and ulcerated rapidly. Furthermore, massive hemorrhage from the tumor occurred 5 weeks after bevacizumab-based therapy initiation. Although hemostasis was achieved by manual compression, the patient required blood transfusion for the massive blood loss. She eventually succumbed to respiratory failure. This case report demonstrates that primary breast cancer lesions with skin involvement have the potential to cause massive hemorrhage after bevacizumab-based treatment.

[A retrospective study of high-dose toremifene treatment for patients with aromatase inhibitor refractory advanced or metastatic hormone receptor-positive breast cancer]

Aromatase inhibitors (AI) have largely replaced tamoxifen as the first-line of treatment for postmenopausal women with advanced or metastatic hormone-receptor-positive breast cancer. However, there is no established strategy for treating AI refractory cases. In this study, we investigated the efficacy of high-dose Toremifene therapy (HD-TOR). From January 2001 through April 2010, nineteen patients received 120 mg of TOR daily. The overall response rate was 36.8% (CR; 1, PR; 6), and the clinical benefit was 47.4%. The clinical benefit rate to each of the metastatic organs were: lung, 42.9%; bone, 13%; liver, 25%; and lymph node, 40%. A higher clinical benefit rate was observed in lung or lymph node metastases. The clinical benefit rate of HD-TOR as first to third-line therapy was 50%, which was more effective than that of fourth-line therapy. Our data suggests that HD-TOR may be one of the effective treatment strategies for patients with AI refractory advanced or metastatic hormone receptor-positive breast cancer.

CSLEX (Sialyl Lewis X) is a useful tumor marker for monitoring of breast cancer patients

BACKGROUND

CSLEX is a type II carbohydrate antigen that interacts with the CSLEX-1 monoclonal antibody. CSLEX in combination with carbohydrate antigen 15-3 may be more useful than Carcinoembryonic Antigen with carbohydrate antigen 15-3 as tumor markers for monitoring of breast cancer.

METHODS

The serum levels of tumor markers, including CSLEX, were measured in 480 consecutive breast cancer patients with or without metastasis who visited the outpatient clinic of the Division of Breast and Endocrine Surgery, Shinshu University Hospital, between April 2007 and September 2007.

RESULTS

Serum levels of each of the tumor markers correlated significantly with the status of metastasis (P < 0.01). Combinations of Carcinoembryonic Antigen and carbohydrate antigen 15-3, Carcinoembryonic Antigen and Nation Cancer Center-Stomach-439, Carcinoembryonic Antigen and CSLEX, carbohydrate antigen 15-3 and Nation Cancer Center-Stomach-439, and carbohydrate antigen 15-3 and CSLEX levels also correlated significantly with the status of metastasis (P < 0.01). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were almost the same for CSLEX and Nation Cancer Center-Stomach-439, which are both type II carbohydrate antigens. The cutoff indexes of serum CSLEX and Nation Cancer Center-Stomach-439 for detection of breast cancer metastasis were 38.8 ± 52.7-fold and 22.1 ± 27.8-fold, respectively (P = 0.16).

CONCLUSIONS

These data suggest that the diagnostic values of CSLEX and Nation Cancer Center-Stomach-439 are similar in single or combined use. However, the cutoff index of serum CSLEX tended to be higher than that of Nation Cancer Center-Stomach-439, which may make CSLEX more useful for detection of breast cancer metastasis.

Correlation of hENT1 expression with response and survival in non-small cell lung cancer patients treated with gemcitabine-containing chemotherapy

e22032

Background: The most active gemcitabine uptake has been found via the human equilibrative nucleoside transporter 1 (hENT1). This study was to explore the prognostic impact of the hENT1 on response and survival in Non-small lung cancer (NSCLC) patients treated with gemcitabine-containing chemotherapy. Methods: We developed polyclonal antibody for hENT1. Then we stained hENT1 expression by immunohistochemical analysis in 24 biopsy samples of NSCLC which was formaline-fixed, paraffin- embedded tissues. We were treated with gemcitabine alone or gemcitabine-containing chemotherapy until third-line regimen. Results: They comprised 16 males and 8 females with a median age of 63 years (range 45–82 years). Seventeen patients had adenocarcinomas, six had squamous-cell carcinomas, and one had a large-cell carcinoma. All patients were treated with gemcitabine- containing chemotherapy, with 9, 12, and 3 patients receiving this as a first-, second-, and third-line therapy, respectively. The hENT1-positive staining in NSCLC samples was significantly associated with response to gemcitabine-containing chemotherapy (Fisher's exact test, P<0.05). Responses to gemcitabine-containing chemotherapy were evident in none of the seven patients with no hENT1 expression. Further 3 years survival differed by hENT1 staining: 714 days for hENT1-positive, 316 days for hENT1-negative (HR 2.86; 95%CI 1.13–15.16, P<0.05). Conclusions: While there are some determinants for gemcitabine sensitivity, hENT1 expression may be a predictive maker for the response and survival to gemcitabine-containing chemotherapy in NSCLC.

No significant financial relationships to disclose.

Phase-specific developmental and reproductive strategies in the desert locust

Locusts modify developmental and reproductive traits over successive generations depending on the population density. A trade-off between developmental rate and body size and between progeny size and number is often observed in organisms. In this study, we present evidence that this rule is evaded by desert locusts, Schistocerca gregaria Forskål, which often undergo outbreaks. Under isolated conditions, large hatchlings, typical of the gregarious forms, grow faster but emerge as larger adults than do small hatchlings typical of the solitarious forms, except for some individuals of the latter group that undergo extra molting. Under crowded conditions, large and small hatchlings grow at a similar rate, but the former become larger adults than the latter. Small hatchlings show a trade-off between development time and body size at maturation, but this constraint is avoided by large hatchlings. Phase-specific, as well as body size-dependent, differences are also detected in reproductive performance. As adult body size increases, females of a solitarious line produce more but slightly smaller eggs, whereas those of a gregarious line produce more and larger eggs. Total egg mass per pod is larger in gregarious forms than in solitarious forms. A trade-off between egg size and number is shown by a solitarious line but not by a gregarious line that produces relatively large eggs with similar numbers of eggs per pod. These results suggest that phase transformation involves not just a shift of resource allocation but also an enhanced capability expressed in response to crowding.

Calcium pyrophosphate dihydrate deposition in the transverse ligament of the atlas: an unusual cause of cervical myelopathy

A 75-year-old male presented with progressive myelopathy due to massive retro-odontoid deposits of calcium pyrophosphate dehydrate (CPPD) crystals. Magnetic resonance imaging revealed a non-enhanced isointense extradural mass on a T1-weighted image and a heterogeneous intense mass on a T2-weighted image. Computed tomography (CT) showed linear calcification within the mass. The mass was resected via a posterolateral approach resulting in marked improvement of the symptoms. Histological examination revealed birefringent rhomboid crystals consistent with CPPD. The preoperative differential diagnosis of periodontoid CPPD deposition disease in the elderly population should be considered, particularly if CT studies demonstrate small areas of calcification within the retro-odontoid mass.

[A case of nonocclusive mesenteric ischemia (NOMI) which occurred in a patient with torsion of gallbladder]

We report a case of nonocclusive mesenteric ischemia (NOMI) which occurred in a patient with torsion of gallbladder. A 91-year-old woman was admitted to the hospital and was diagnosed of acute cholecystitis. The next day, she went into shock. Then, we diagnosed her illness as torsion of gallbladder by computed tomography and ultrasonography, and performed an emergency operation. After cholecystectomy, it was recognized that the wide range of the small intestine had become necrotic sporadically. We diagnosed it as NOMI, and performed the wide resection of the small intestine followed by making double stomas. There is no previous report of NOMI associated with torsion of gallbladder. We guess the cause of NOMI in this case would be dehydration because of gallbladder torsion. NOMI has high mortality. Early diagnosis and early treatment are of great importance in NOMI.

Increased nuclear localization of transcription factor Y-box binding protein 1 accompanied by up-regulation of P-glycoprotein in breast cancer pretreated with paclitaxel

PURPOSE

The Y-box binding protein 1 (YB-1) regulates expression of P-glycoprotein encoded by the MDR1 gene. There have been no previous studies regarding the involvement of YB-1 in the development of resistance to paclitaxel. The present study was done to examine how paclitaxel affects the localization and expression of YB-1 in breast cancer.

EXPERIMENTAL DESIGN

We evaluated the expression and localization of YB-1 and P-glycoprotein in breast cancer tissues obtained from 27 patients before and after treatment with paclitaxel. The effect of paclitaxel on localization of cellular YB-1 was examined by using GFP-YB-1. Interaction of YB-1 with the Y-box motif of the MDR1 promoters was studied by electrophoretic mobility shift assay. The effects of paclitaxel on MDR1 promoter activity were examined by luciferase assay.

RESULTS

Of 27 breast cancer tissues treated with paclitaxel, nine (33%) showed translocation of YB-1 from the cytoplasm to the nucleus together with increased expression of P-glycoprotein during the course of treatment. Twelve breast cancer tissues (44%) showed neither translocation of YB-1 nor increased expression of P-glycoprotein. Nuclear translocation of YB-1 was correlated significantly with increased expression of P-glycoprotein (P=0.0037). Confocal analysis indicated that paclitaxel induced nuclear translocation of green fluorescent fused YB-1 in MCF7 cells. Furthermore, binding of YB-1 to the Y-box of MDR1 promoter was increased in response to treatment with paclitaxel. In addition, MDR1 promoter activity was significantly up-regulated by paclitaxel in MCF7 cells (P<0.001).

CONCLUSIONS

The results of the present study suggested that YB-1 may be involved in the development of resistance to paclitaxel in breast cancer.

Altered regulation of c-jun and its involvement in anchorage-independent growth of human lung cancers

The c-jun oncogene is frequently overexpressed in non-small-cell lung cancers (NSCLC), but its functional involvement in lung cancer development has not been clearly elucidated. In this study, we found that among the immediate-early serum responsible genes, exemplified by c-jun, c-fos and c-myc, induction of c-jun in a human bronchial epithelial cell line, BEAS-2B, was dependent on anchorage, in contrast to clear induction of c-fos and c-myc under both anchorage-dependent and -independent conditions. In fact, forced expression of c-jun in BEAS-2B cells significantly increased cell viability and colony formation in soft agar. Furthermore, we also found that such anchorage-dependent regulation of c-jun was lost in a significant fraction of human lung cancer cell lines. Interestingly, suppressed anchorage-independent but not anchorage-dependent growth was noted by constitutive expression of a dominant-negative c-jun mutant in a lung cancer cell line showing dysregulated and sustained c-jun expression in the absence of anchorage. These findings suggest that dysregulated c-jun expression may be involved in the acquisition of anchorage independence in the process of human lung carcinogenesis.