Phase II trial of GTX chemotherapy in metastatic pancreatic cancer

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Background: Preclinical studies suggest synergy between gemcitabine (G), docetaxel (T) and capecitabine (X). This GTX regimen was designed to inhibit MEK-ERK phosphorylation and increase BAX and BAK and also decrease BCL-2 in pancreatic cancer cell lines. Based on these findings, we pursued a prospective clinical trial evaluating the activity of GTX in previously untreated patients with metastatic pancreatic cancer. Methods: Patients with histologically confirmed metastatic adenocarcinoma of the pancreas, median age 60, 63% male, ECOG PS 0–2, received capecitabine 1500mg/m2/day total orally in divided doses, days 1 thru 14, gemcitabine 750mg/m2 IV over 75 minutes followed by docetaxel 30mg/m2 IV on days 4 and 11 on a 21 day cycle. Scans were completed every 9 to 10 weeks to assess for tumor response by RECIST criteria. Treatment was continued until evidence of disease progression, intolerable toxicity, surgery or a delay in treatment greater than 6 weeks. The primary endpoint was response rate. Secondary endpoints were overall survival (OS) measured as time from start of GTX to death, time to treatment failure (TTF) measured as time from start of GTX to disease progression or other reason for a halt in therapy. Results: Forty-three patients were enrolled at two centers between May 2004 and January 2007. Forty-one patients were eligible for assessment by intent to treat analysis. 35 patients (85%) had liver metastases. 9 patients (21.9%) had partial responses and 17 patients (41.5%) had stable disease. The one year survival rate was 56%. Two year survival rate was 14.6%. The median OS was 14.5 months. The median TTF was 6.9 months. Grade 3 and 4 toxicities included leukopenia (31.6%), neutropenia (29.2%), thrombocytopenia (12.2%), infection (12.5%), and mucositis (7.5%). Conclusions: The combination of gemcitabine, docetaxel, and capecitabine has activity in metastatic pancreatic cancer with a median survival over 1 year. A randomized phase III trial is in planning.

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The Ti-B-N system: nanocomposite nc-TiN/a-(TiB2, BN) and nano-multilayer nc-TiN/a-TiBN thin films

The nanostructures and mechanical properties of nanocomposite nc-TiN/a-(TiB2, BN) and nanostructured multilayers nc-TiN/a-TiBN were investigated using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), microindentation, and stress measurements. It was found that the monolayer Ti-B-N thin films consisted of nanometer-sized crystalline (nc-) Ti(N, B) embedded into amorphous (a-) (TiB2, BN) matrix. When B content was below approximately 16 at.%, two different-sized nanocrystallites with mean grain sizes of approximately 3 and 9 nm respectively were embedded in a-TiB2. With increasing B incorporation (> approximately 27 at.%), more uniform nanograins was embedded a-(TiB2, BN). Incorporation of B not only decreased the size of nanocrystallites, but also gave rise to twinning deformation in nanocrystallites. A maximum hardness of approximately 44 GPa was achieved at B content of 19 at.%. It was also found that the nanostructure and mechanical behaviors of nc-TiN/a-TiBN multilayers was dependent on the modulation length (bilayer thickness A). Decrease of Lambda made the preferred orientation of nc-TiN gradually transform from (200) to (111). A maximum hardness of approximately 30 GPa was achieved at Lambda = 1.8 nm. Deflection from this Lambda value decreased hardness. By contrast, the residual compressive stress value monotonically increased with decrease of A. The enhancement of the hardness was due to the coherent stresses and the structural barriers to dislocation motion in the interface.

A viable mouse model of factor X deficiency provides evidence for maternal transfer of factor X

BACKGROUND

Activated factor X (FXa) is a vitamin K-dependent serine protease that plays a pivotal role in blood coagulation by converting prothrombin to thrombin. There are no reports of humans with complete deficiency of FX, and knockout of murine F10 is embryonic or perinatal lethal.

OBJECTIVE

We sought to generate a viable mouse model of FX deficiency.

METHODS

We used a socket-targeting construct to generate F10-knockout mice by eliminating F10 exon 8 (knockout allele termed F10(tm1Ccmt), abbreviated as '-'; wild-type '+'), and a plug-targeting construct to generate mice expressing a FX variant with normal antigen levels but low levels of FX activity [4-9% normal in humans carrying the defect, Pro343-->Ser, termed FX Friuli (mutant allele termed F10(tm2Ccmt), abbreviated as F)].

RESULTS

F10 knockout mice exhibited embryonic or perinatal lethality. In contrast, homozygous Friuli mice [F10 (F/F)] had FX activity levels of approximately 5.5% (sufficient to rescue both embryonic and perinatal lethality), but developed age-dependent iron deposition and cardiac fibrosis. Interestingly, F10 (-/F) mice with FX activity levels of 1-3% also showed complete rescue of lethality. Further study of this model provides evidence supporting a role of maternal FX transfer in the embryonic survival.

CONCLUSIONS

We demonstrate that, while complete absence of FX is incompatible with murine survival, minimal FX activity as low as 1-3% is sufficient to rescue the lethal phenotype. This viable low-FX mouse model will facilitate the development of FX-directed therapies as well as investigation of the FX role in embryonic development.

A viable mouse model of factor X deficiency provides evidence for maternal transfer of factor X

BACKGROUND

Activated factor X (FXa) is a vitamin K-dependent serine protease that plays a pivotal role in blood coagulation by converting prothrombin to thrombin. There are no reports of humans with complete deficiency of FX, and knockout of murine F10 is embryonic or perinatal lethal.

OBJECTIVE

We sought to generate a viable mouse model of FX deficiency.

METHODS

We used a socket-targeting construct to generate F10-knockout mice by eliminating F10 exon 8 (knockout allele termed F10(tm1Ccmt), abbreviated as '-'; wild-type '+'), and a plug-targeting construct to generate mice expressing a FX variant with normal antigen levels but low levels of FX activity [4-9% normal in humans carrying the defect, Pro343-->Ser, termed FX Friuli (mutant allele termed F10(tm2Ccmt), abbreviated as F)].

RESULTS

F10 knockout mice exhibited embryonic or perinatal lethality. In contrast, homozygous Friuli mice [F10 (F/F)] had FX activity levels of approximately 5.5% (sufficient to rescue both embryonic and perinatal lethality), but developed age-dependent iron deposition and cardiac fibrosis. Interestingly, F10 (-/F) mice with FX activity levels of 1-3% also showed complete rescue of lethality. Further study of this model provides evidence supporting a role of maternal FX transfer in the embryonic survival.

CONCLUSIONS

We demonstrate that, while complete absence of FX is incompatible with murine survival, minimal FX activity as low as 1-3% is sufficient to rescue the lethal phenotype. This viable low-FX mouse model will facilitate the development of FX-directed therapies as well as investigation of the FX role in embryonic development.

Increased response to morphine in mice lacking protein kinase C epsilon

The protein kinase C (PKC) family of serine-threonine kinases has been implicated in behavioral responses to opiates, but little is known about the individual PKC isozymes involved. Here, we show that mice lacking PKCepsilon have increased sensitivity to the rewarding effects of morphine, revealed as the expression of place preference and intravenous self-administration at very low doses of morphine that do not evoke place preference or self-administration in wild-type mice. The PKCepsilon null mice also show prolonged maintenance of morphine place preference in response to repeated testing when compared with wild-type mice. The supraspinal analgesic effects of morphine are enhanced in PKCepsilon null mice, and the development of tolerance to the spinal analgesic effects of morphine is delayed. The density of mu-opioid receptors and their coupling to G-proteins are normal. These studies identify PKCepsilon as a key regulator of opiate sensitivity in mice.