Adjuvant Chemotherapy for Endometrial Cancer (ACE) trial: A randomized phase II study for advanced endometrial carcinoma.

This study evaluated the feasibility and efficacy of three postoperative adjuvant chemotherapy regimens for endometrial cancer. Endometrioid cancer patients with intermediate-risk stage I and II or high-risk stage III and IV disease were randomly assigned to receive six cycles of either paclitaxel-epirubicin-carboplatin (TEC), paclitaxel-anthracycline (doxorubicin)-carboplatin (TAC), or dose-dense paclitaxel-carboplatin (ddTC). The primary end-point was the completion rate (CRate) of six cycles of treatment. The secondary end-points were progression-free survival (PFS) and overall survival (OS). One hundred and one patients were treated as follows: 33 received TEC, 33 TAC, and 35 ddTC. The CRates for TEC, TAC, and ddTC were 94%, 64%, and 69%, respectively (P = .005). The TEC CRate was significantly higher than for the other two groups. However, the PFS and OS outcomes were not statistically different between the three groups. The 2-year survival rates were 94%, 97%, and 97% for TEC, TAC, and ddTC, respectively. When compared to the current standard treatments for endometrial cancer, TEC is a promising candidate for a phase III trial based on its significantly superior CRate and equivalent PFS and OS. This study is registered with UMIN Clinical Trials Registry (UMIN000008911).

Subsequent menstrual disorder after spontaneous menarche in Turner syndrome.

OBJECTIVE: Turner syndrome (TS) is a congenital disease characterized by delayed puberty, ovarian dysgenesis and short stature. Although most patients are diagnosed with primary amenorrhea, approximately 15-20% of patients with TS are reported to have spontaneous menarche. However, little is known about their menstruation status after spontaneous menarche. In the current study, we investigated the menstrual abnormalities after spontaneous menarche in TS patients. DESIGN: Retrospective study. PATIENTS: This study included TS patients with spontaneous menarche at Osaka Police Hospital or Komura Women's Clinic between April 2015 and December 2019. MEASUREMENTS: Data regarding the age of menarche, menstruation status and chromosomal karyotype were collected and retrospectively analyzed. RESULTS: Of 172 TS patients, 32 with spontaneous menarche were identified. The median age of menarche was 12 years old. Premature ovarian insufficiency (POI) after menarche was observed in 12 patients (37.5%) and the median age at menopause was 20 years old. The average period from spontaneous menarche to menopause in these patients was 5.1 years. Five patients (15.6%) had irregular menstruation and 15 (46.9%) had regular menstruation. When examined according to the structural abnormality of the X chromosome, all patients with structural abnormality of the X chromosome were diagnosed with POI after spontaneous menarche, and none with mosaic without structural abnormality were diagnosed with POI. CONCLUSION: Approximately one-third of TS patients with spontaneous menarche were diagnosed with POI after menarche for an average of 5.1 years. Counseling is required for TS patients and their parents, including information about menstrual abnormalities or fertility preservation.

Synthesis and evaluation of novel dolastatin 10 derivatives for versatile conjugations.

Dolastatin 10 (1) is a highly potent cytotoxic microtubule inhibitor (cytotoxicity IC50 < 5.0 nM) and several of its analogs have recently been used as payloads in antibody drug conjugates. Herein, we describe the design and synthesis of a series of novel dolastatin 10 analogs useful as payloads for conjugated drugs. We explored analogs containing functional groups at the thiazole moiety at the C-terminal of dolastatin 10. The functional groups included amines, alcohols, and thiols, which are representative structures used in known conjugated drugs. These novel analogs showed excellent potency in a tumor cell proliferation assay, and thus this series of dolastatin 10 analogs is suitable as versatile payloads in conjugated drugs. Insights into the structure-activity relationships of the analogs are also discussed.

Efficacy of raloxifene hydrochloride for the prevention of health care problems in patients who undergo surgery for endometrial cancer: a multicenter randomized clinical trial.

OBJECTIVE: Removal of the ovaries is common during surgery for endometrial cancer. However, because loss of the ovaries can cause several health problems in patients, strategies for the prevention of such problems need to be established. Hence, we decided to conduct a multicenter randomized clinical trial to assess the effect of raloxifene on bone mineral density (BMD), bone metabolism, and the lipid profile of patients who had undergone surgery for patients with endometrial cancer. MATERIALS AND METHODS: Patients with endometrial cancer were enrolled after treatment. The participants were randomized into 2 groups: group 1 included 39 women who received alfacalcidol (1 µg/d) alone and group 2 included 37 women who received alfacalcidol and the test drug, raloxifene hydrochloride, at a dose of 60 mg/d. The BMD of lumbar spine and femoral neck, serum bone markers, as well as lipid profile parameters were evaluated at enrollment as well as 6, 12, and 24 months after the enrollment. The primary efficacy end point was the percentage change from baseline to 24 months in lumbar spine (L2-L4) and femoral neck BMD. RESULTS: Sixty-four women completed the 24-month study. At 24 months, the lumbar and femoral neck BMDs were significantly increased in group 2 compared with group 1 (3.5% vs -0.8% and 2.3% vs -2.8%, respectively). In group 2, low-density lipoprotein-cholesterol levels were significantly reduced by 13.6% and serum N-terminal telopeptide of type I collagen as well as bone-specific alkaline phosphatase values were significantly reduced by 16.7% and 25.7%, respectively. The patients who received adjuvant therapy for endometrial cancer showed a significantly higher response to raloxifene (5.8% vs 1.9%). Recurrence was detected in 2 (2.6%) patients in group 1. No severe adverse events were noted in any patient during the study period. CONCLUSIONS: Raloxifene exerts positive effects on BMD, bone metabolism, and lipid profile parameters and could provide an improved therapeutic option for patients with endometrial cancer.

Case of uterine papillary serous carcinoma following tamoxifen treatment that could not be diagnosed during screening.

This case involved a 69-year-old woman who had been taking tamoxifen for 5 years after breast cancer surgery. She was referred to our clinic for endometrial cancer screening when tamoxifen was first prescribed. Subsequently, transvaginal ultrasonography and endometrial cytology were performed every 6 months. Despite these regular examinations, stage IVb papillary serous carcinoma was detected 8 months after the end of tamoxifen administration. Total abdominal hysterectomy was performed, but only a small polyp was seen upon macroscopic examination of the uterus. However, papillary serous carcinoma was found microscopically in almost all lymphovascular spaces in the uterus from the endometrium to the serosa. On the surface of the polyp, only endometrial intraepithelial carcinoma with positive immunostaining for p53 was detected. Chemotherapy, including a platinum compound, was administrated, but unfortunately it was ineffective and the patient died of her disease 14 months after the operation.

[A case of poorly differentiated adenocarcinoma of the uterine cervix treated with paclitaxel and carboplatin after positive PAX 8 immunostaining].

PAX 8 is a paired-box gene that plays an important role in the embryogenesis of the thyroid gland, Müllerian ducts, and renal/upper urinary tract. PAX 8 expression is observed in carcinomas from each of these sites. Accordingly, PAX 8 immunostaining has been reported to be useful for the diagnosis of these carcinomas. Here, we report a case in which PAX 8 was useful for the diagnosis of a patient with cervical adenocarcinoma and multiple metastases. A 55-year-old female patient complained of cough and genital bleeding. Examination revealed a uterine cervical mass, masses in both breasts, and enlargement of the lymph nodes and subcutaneous nodules. Histology of the uterine cervical mass biopsy revealed a poorly differentiated adenocarcinoma. Cytology of the aspiration biopsy specimens of the breast masses indicated scirrhous cancer. PAX 8 immunostaining of the uterine cervical mass and breast mass biopsies was positive. We determined that the breast masses were metastases of the cervical adenocarcinoma and decided to treat the patient with chemotherapy consisting of paclitaxel and carboplatin. A partial response was observed. A hysterectomy was performed 5 months after chemotherapy because corpus cancer was newly diagnosed. The cervical adenocarcinoma was undetectable in the surgical specimen. Fifteen months have passed since the completion of chemotherapy and the metastases has been under control.

Estrogen therapy initiated at an early age increases bone mineral density in Turner syndrome patients.

Patients with Turner syndrome (TS) almost develop osteoporosis, resulting from chromosomal deficiency and estrogen deficiency by gonadal dysgenesis. The aim of this study was to assess bone mineral density (BMD) during continuous estrogen therapy in young TS patients by measuring lumbar spine BMD of 67 TS patients using dual-energy X-ray absorptiometry. Twenty-seven patients who were treated with adult-doses of estrogen prior to the first evaluation, exhibited a significantly higher initial BMD than 30 patients treated with low-dose estrogen therapy and 10 patients without estrogen therapy (0.808 g/cm², 0.714 g/cm², and 0.664 g/cm², respectively). During continuous adult-dose estrogen therapy, BMD significantly increased in each group (maximum BMD during the study, 0.842 g/cm², 0.790 g/cm², and 0.724 g/cm², respectively). Initial and maximum BMD showed significant negative correlation with the age at which adult-dose estrogen therapy was initiated (r = -0.57 and -0.45, respectively). Among the patients not treated with adult-dose estrogen therapy prior to the first evaluation, the annual increase in the rate and amount of BMD was significantly higher when adult-dose estrogen therapy was initiated before age 18 (rate, 4.4 % before age 18 vs. 3.1 % after age 18; amount, 0.03 g/cm² before age 18 vs. 0.02 g/cm² after age 18). In summary, estrogen therapy increased BMD in young TS patients and might be more effective if initiated by age 18.

2-({6-[(3R)-3-amino-3-methylpiperidine-1-yl]-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydro-5H-pyrrolo[3,2-d]pyrimidine-5-yl}methyl)-4-fluorobenzonitrile (DSR-12727): a potent, orally active dipeptidyl peptidase IV inhibitor without mechanism-based inactivation of CYP3A.

We report on the identification of 2-({6-[(3R)-3-amino-3-methylpiperidine-1-yl]-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydro-5H-pyrrolo[3,2-d]pyrimidine-5-yl}methyl)-4-fluorobenzonitrile (DSR-12727) (7a) as a potent and orally active DPP-4 inhibitor without mechanism-based inactivation of CYP3A. Compound 7a showed good DPP-4 inhibitory activity (IC(50)=1.1 nM), excellent selectivity against related peptidases and other off-targets, good pharmacokinetic and pharmacodynamic profile, great in vivo efficacy in Zucker-fatty rat, and no safety concerns both in vitro and in vivo.

Discovery of new chemotype dipeptidyl peptidase IV inhibitors having (R)-3-amino-3-methyl piperidine as a pharmacophore.

Structures containing the (R)-3-amino-3-methyl piperidine unit as a new pharmacophore moiety have been shown to possess moderate inhibitory activity for DPP-4 with good pharmacokinetics profile. One of these compounds was found to have good oral bioavailability and PK/PD profile in ZF-rat.

A case in which laparoscopic right salpingo-oophorectomy was performed in a patient with a lumboperitoneal shunt.

INTRODUCTION: Ventriculoperitoneal (VP shunts) and lumboperitoneal shunts (LP shunts) are used to treat hydrocephalus. The effectiveness of LP shunts has recently been demonstrated. Due to population aging, the number of patients with LP shunts is expected to increase. PRESENTATION OF CASE: A 51-year-old female, in whom an LP shunt had been inserted to treat hydrocephalus after a subarachnoid hemorrhage, underwent laparoscopic right salpingo-oophorectomy for a right endometriotic cyst. We consulted a neurosurgeon and confirmed the route of the shunt. We started a normal laparoscopic procedure. The head of the shunt tube was located in Douglas' pouch and was an obstacle to the procedure. We moved the head of the shunt tube to the vesicouterine pouch and successfully conducted the standard operation. We report the case together with a literature review. DISCUSSION: There have been several reports about gynecological laparoscopic surgery being performed in patients with VP shunts. On the other hand, we did not find any English literature about gynecological laparoscopic surgery being conducted in patients with LP shunts during a PubMed search. CONCLUSION: This is the first report about gynecological laparoscopic surgery being performed in a patient with an LP shunt.

Monoclonality of composite large cell neuroendocrine carcinoma and mucinous epithelial tumor of the ovary: a case study.

A rare case of mixed carcinoma of the ovary is reported, composed of a large cell neuroendocrine carcinoma and a mucinous borderline endocervical tumor. The large cell neuroendocrine carcinoma was composed of solid nests, sheets, and trabeculae of medium to large-sized cells, and was positive for synaptophysin. The mucinous epithelial tumor varied in appearance from a borderline to an intraepithelial carcinoma, and showed sparsely scattered immunoreactivity for chromogranin-A. Using an X-chromosome clonality assay, these 2 components showed patterns of monoclonality. These results suggest that the large cell neuroendocrine carcinoma may have arisen from the mucinous epithelial tumor.

Coexistence of a clear cell adenocarcinoma and an adenosarcoma with a heterologous rhabdomyosarcoma in an endometriotic cyst of the ovary: a case study.

SUMMARY: A rare case of a clear cell adenocarcinoma and an adenosarcoma coexisting with a heterologous rhabdomyosarcoma in an endometriotic cyst of the ovary is reported. The tumor was composed of a cystic area and a solid area arising from the cyst wall. In the cystic lesion, a detached polypoid mass was also identified. The cyst wall was lined with a single layer of endometrial-type cells, whereas the solid area was composed of a clear cell adenocarcinoma. In the detached polypoid mass, an exophytic leaf-like pattern containing benign endometrial-type cells and squamous epithelial and rhabdomyosarcoma components, which were positive for desmin and myoglobin, was observed. Using X-chromosomal clonality assay, these clear cell adenocarcinoma and adenosarcoma components showed patterns of polyclonality. To the authors' knowledge, this is the first reported case of a clear cell adenocarcinoma and an adenosarcoma coexisting with heterologous rhabdomyosarcoma in an endometriotic cyst of the ovary.

Cesarean scar pregnancies successfully treated with methotrexate.

Three cases of cesarean scar pregnancy successfully treated with methotrexate are described. The diagnosis was confirmed by transvaginal sonographic examinations showing a well-formed gestational sac in the myometrium of the lower uterine segment. Initial treatment with a systemic injection of 50 mg of methotrexate was not sufficient, and multiple doses were required to obtain a complete remission in two cases. In a case with a beta-hCG level of more than 20,000 mIU/mL with a viable embryo in a gestational sac, a combination of systemic and local treatment with methotrexate was required. It took 7-11 weeks for the beta-hCG level to become undetectable and 12-17 weeks for the cesarean scar pregnancy mass to disappear completely.

A phase I/II study of GLIF combination chemotherapy for taxane/platinum-refractory/resistant endometrial cancer (GOGO-EM2).

PURPOSE: Development of new treatment strategies for endometrial cancer that has become refractory or resistant to taxane/platinum is a critical need. The present study was a phase I/II study of gemcitabine, levofolinate, irinotecan, and 5-fluorouracil (5-FU) (GLIF) combination chemotherapy to determine optimal dosages, safety, and efficacy. METHODS: Taxane/platinum-resistant or -refractory endometrial disease was defined as tumor progression within 6 months after a taxane/platinum-based regimen. Maximum tolerated dose was investigated by a 3 + 3-designed phase I study. The phase II study was conducted using the recommended doses determined in the phase I study. RESULTS: The dosages recommended for the phase II trial were determined, in the phase I trial, to be: gemcitabine 800 mg/m2, levofolinate 100 mg/m2, irinotecan 80 mg/m2, and 5-FU 1000 mg/m2. Thirty patients were enrolled, including the three patients who received GLIF therapy at the same dose as the recommended phase II dose in the phase I study. Two patients were excluded at this point due to study protocol violations, and the remaining 28 patients were included for analysis. Phase II revealed that the response and disease control rates were 7.1% (2/28) and 39.3% (11/28), respectively, and that the median PFS and OS were 3 months [95% confidence interval (CI) 3-7] and 12 months (95% CI 9-17), respectively. Febrile or grade 4 neutropenia was observed in 14% (4/28) of the cases. Grade 3 or 4 thrombocytopenia was not observed. CONCLUSION: We found that GLIF combination chemotherapy is potentially a useful treatment option for endometrial cancers refractory or resistant to taxane/platinum-based chemotherapy.

Peripheral quantitative computed tomography (pQCT) is useful for monitoring bone mineral density of the patients who receive hormone replacement therapy.

OBJECTIVE: A forearm fracture (Colles' fracture) is often the first sign of osteoporosis and should alert the patient and physician to the possibility of underlying skeletal fragility. Therefore, the establishment of a more accurate and reliable method for the measurement of bone mineral density (BMD) at the distal radius would be beneficial for the patients who suffer from osteoporosis. The objective of the present study was to evaluate the usefulness of peripheral quantitative computed tomography (pQCT) to assess the change of BMD at the distal radius in early postmenopausal women who receive hormone replacement therapy (HRT). METHODS: Twenty healthy early postmenopausal women who were diagnosed as osteoporosis or osteopenia were randomized to either HRT or placebo treatment. We analyzed BMD of the distal radius by pQCT, lumbar spine by dual-energy X-ray absorptiometry (DXA) and the biochemical markers of bone turn over (osteocalcin, deoxypyridinoline) every 6 months. RESULTS: The placebo group showed a significant decrease from the baseline in the trabecular BMD of the radius at 12 months (7.4+/-2.5%) (p<0.05), whereas the HRT group showed a slight increase (0.7+/-2.2%). The changes in the trabecular BMD of the radius between the HRT and placebo groups were statistically different at 12 months (p<0.05). On the other hand, in the cortical BMD of the radius, no significant differences were seen between the changes of bone densities in the HRT and control groups after 1 year of treatment. pQCT could detect a significant loss of BMD of the radius in early postmenopausal women after 1 year and HRT prevented its loss. CONCLUSION: Our preliminary clinical trial showed that pQCT might be useful for the early detection of bone loss in early postmenopausal women and for the monitoring BMD of the patients who receive HRT.

Estrogen and raloxifene inhibit the monocytic chemoattractant protein-1-induced migration of human monocytic cells via nongenomic estrogen receptor alpha.

OBJECTIVE: To investigate the effects of estradiol (E2) and raloxifene on the migration of human monocytic THP-1 cells to endothelium. DESIGN: A prospective comparative study. THP-1 cells, a human acute monocytic leukemia cell line, were used for the study. Migration assays were performed using transwell inserts. THP-1 cells were exposed to E2 or raloxifene in the presence of monocytic chemoattractant protein-1 (MCP-1), a major chemoattractant for monocytes. The cells were transfected with small interfering RNA (siRNA) against estrogen receptor (ER) alpha and ERbeta for gene silencing. ER expression was evaluated by Western blot analysis. RESULTS: MCP-1 induced the migration of the cells for 90 minutes. The addition of E2 or raloxifene significantly inhibited the MCP-1-induced migration for 90 minutes. Preincubation of THP-1 cells with an ER antagonist, ICI 182780, significantly attenuated the inhibitory effects of E2 and raloxifene. Whereas transfection with siRNA of ERalpha significantly attenuated the inhibition by E2 of MCP-1-induced monocyte migration, transfection with control siRNA or siRNA of ERbeta had no effect on the rapid inhibitory action of E2. Moreover, preincubation of THP-1 cells with a transcriptional inhibitor, actinomycin D, had no effect on the rapid inhibitory action of E2. CONCLUSIONS: Our findings suggest that both E2 and raloxifene inhibited the MCP-1-induced monocyte migration through nongenomic ERalpha. This result may explain one of the antiatherosclerotic effects of E2 and raloxifene on vasculature.

Induction of hTERT expression and phosphorylation by estrogen via Akt cascade in human ovarian cancer cell lines.

We examined the mechanism by which estrogen regulates telomerase activity in Caov-3 human ovarian cancer cell lines, which express ER, to determine whether the regulation affects the expression and/or phosphorylation of the telomerase catalytic subunit (hTERT). 17beta-Estradiol (E(2)) induced telomerase activity and hTERT expression. Transient expression assays using luciferase reporter plasmids containing various fragments of hTERT promoter showed that the estrogen-responsive element appeared to be partially responsible for the E(2)-induced activation of the hTERT promoter. Either pretreatment with a phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002, or transfection with a dominant-negative Akt attenuated the E(2)-induced activation of the hTERT promoter. In addition, estrogen induced the phosphorylation of IkappaB inhibitor protein via the Akt cascade, and cotransfection with a dominant-negative subunit of NFkappaB attenuated the response of the ERE-deleted hTERT promoter to E(2). Moreover, E(2) induced the phosphorylation of hTERT, the association of 14-3-3 protein and NFkappaB with hTERT, and nuclear accumulation of hTERT in an Akt-dependent manner. These results indicate that E(2) induces telomerase activity not only by transcriptional regulation of hTERT via an ERE-dependent mechanism and a PI3K/Akt/NFkappaB cascade, but also by post-transcriptional regulation via Akt-dependent phosphorylation of hTERT. Thus, the phosphorylation of Akt is a key event in the induction of telomerase activity by E(2) in human ovarian cancer cells.

Regioselective aromatic C-H silylation of five-membered heteroarenes with fluorodisilanes catalyzed by iridium(I) complexes.

The aromatic C-H silylation of five-membered heteroarenes with 1,2-di-tert-butyl-1,1,2,2-tetrafluorodisilane regioselectively proceeded at 120 degrees C in octane in the presence of a catalytic amount of iridium(I) complexes generated from 1/2[Ir(OMe)(COD)]2 and 2-tert-butyl-1,10-phenanthroline.

Inhibition of inhibitor of nuclear factor-kappaB phosphorylation increases the efficacy of paclitaxel in in vitro and in vivo ovarian cancer models.

We investigated whether inhibition of nuclear factor-kappaB (NFkappaB) increases the efficacy of paclitaxel in in vitro and in vivo ovarian cancer models. Treatment of paclitaxel-sensitive Caov-3 cells with paclitaxel transiently activated the phosphorylation of Akt, the phosphorylation of IkappaB kinase (IKK), and the phosphorylation of inhibitor of NFkappaB (IkappaBalpha). Paclitaxel also caused a transient increase in NFkappaB activity, followed by a decrease in NFkappaB activity. We show an association between Akt and IKK and show that the phosphorylation of IKK induced by paclitaxel is blocked by treatment with a phosphatidylinositol 3-kinase inhibitor (wortmannin or LY294002). Furthermore, interference of the Akt signaling cascade inhibits the transient induction of IkappaBalpha phosphorylation and NFkappaB activity by paclitaxel. Inhibition of NFkappaB activity by treatment with an IkappaBalpha phosphorylation inhibitor (BAY 11-7085) attenuated both basal and transient induction of IkappaBalpha phosphorylation by paclitaxel. Treatment with BAY 11-7085 also enhanced the inhibition of NFkappaB activity by paclitaxel for up to 24 hours. In addition, treatment with BAY 11-7085 decreased the viability of cells treated with paclitaxel. Moreover, treatment with BAY 11-7085 increased the efficacy of paclitaxel-induced inhibition of intraabdominal dissemination and production of ascites in athymic nude mice inoculated intraperitoneally with Caov-3 cells. These results suggest that paclitaxel transiently induces NFkappaB activity via the phosphatidylinositol 3-kinase/Akt cascade and that combination therapy with paclitaxel and an NFkappaB inhibitor would increase the therapeutic efficacy of paclitaxel.

Regulation of the PRL promoter by Akt through cAMP response element binding protein.

Regulation of the PI3K-protein kinase B/Akt (serine/threonine kinase) cascade by PRL-releasing peptide (PrRP) and insulin in GH3 rat pituitary tumor cells was investigated. PrRP and insulin rapidly and transiently stimulated the activation of Akt, and the PI3K inhibitor wortmannin blocked the PrRP- or insulin-induced activation of Akt. Both pertussis toxin (10 ng/ml), which inactivates Gi/Go proteins, and expression of a peptide derived from the carboxyl terminus of the beta-adrenergic receptor kinase I, which specifically blocks signaling mediated by the betagamma subunits of G proteins, completely blocked the PrRP-induced Akt activation, suggesting that Gi/Go proteins are involved in PrRP-induced Akt activation, as they are in the activation of ERK by PrRP. Moreover, to determine whether a PI3K-Akt cascade regulates rat PRL (rPRL) promoter activity, we transfected the intact rPRL promoter ligated to the firefly luciferase reporter gene into GH3 cells. PrRP and insulin activated the rPRL promoter activity. Pretreatment with wortmannin or cotransfection with a dominant-negative Akt partially but significantly inhibited the induction of the rPRL promoter by PrRP or insulin. Cotransfection with a constitutively active Akt induced the rPRL promoter activity and cotransfection with a dominant-negative cAMP response element-binding protein (CREB) completely abolished the response of the rPRL promoter to the constitutively active Akt. Furthermore, either treatment with PrRP and insulin or transfection with the constitutively active Akt induced the phosphorylation of CREB. These results suggest that PrRP and insulin activate a PI3K-Akt cascade that is necessary to elicit rPRL promoter activity via a CREB-dependent mechanism.