Relationship of Metabolic Alterations and PD-L1 Expression in Cisplatin Resistant Lung Cancer.

Despite numerous reports on immune checkpoint inhibitor for the treatment of non-small cell lung cancer (NSCLC), the response rate remains low but durable. Thus cisplatin still plays a major role in the treatment of NSCLC. While there are many mechanisms involved in cisplatin resistance, alteration in metabolic phenotypes with elevated levels of reactive oxygen species (ROS) are found in several cisplatin resistant tumors. These resistant cells become more reliant on mitochondria oxidative metabolism instead of glucose. Consequently, high ROS and metabolic alteration contributed to epithelial-mesenchymal transition (EMT). Importantly, recent findings indicated that EMT has a crucial role in upregulating PD-L1 expression in cancer cells. Thus, it is very likely that cisplatin resistance will lead to high expression of PD-L1/PD-1 which makes them vulnerable to anti PD-1 or anti PD-L1 antibody treatment. An understanding of the interactions between cancer cells metabolic reprogramming and immune checkpoints is critical for combining metabolism targeted therapies with immunotherapies.

Gas6/Axl is the sensor of arginine-auxotrophic response in targeted chemotherapy with arginine-depleting agents.

Many human malignancies lack de novo biosynthesis of arginine (Arg) as the key enzyme argininosuccinate synthetase 1 (ASS1) is silenced. These tumors acquire ectopic Arg for survival, and depleting this source by Arg-depleting recombinant enzyme ADI-PEG20 results in cell death. Mechanisms underlying Arg auxotrophy in these tumors and how they respond to Arg-auxotrophic stress are poorly understood. Here, we report that an immediate-early event of Arg-auxotrophic response involves reactive oxygen species-mediated secretion of Gas6, which interacts with its receptor Axl and activates the downstream Ras/PI3K/Akt growth signal leading to accumulation of c-Myc by protein stabilization. Arg-auxotrophic challenge also transcriptionally upregulates c-Myc expression, which provides a feedback mechanism to enhance Axl expression. c-Myc is a positive regulator of ASS1, but elevated ASS1 provides a feedback mechanism to suppress c-Myc and Axl. Our results revealed multiple inter-regulatory pathways in Arg-auxotrophic response, consisting of Axl, c-Myc and ASS1, which regulate Arg homeostasis and ADI-PEG20 sensitivity. These pathways provide potential targets for improving the efficacy of treating Arg-auxotrophic tumors using Arg-deprivation strategies.

Negative argininosuccinate synthetase expression in melanoma tumours may predict clinical benefit from arginine-depleting therapy with pegylated arginine deiminase.

BACKGROUND: Arginine-depleting therapy with pegylated arginine deiminase (ADI-PEG20) was reported to have activity in advanced melanoma in early phase I-II trial, and clinical trials are currently underway in other cancers. However, the optimal patient population who benefit from this treatment is unknown. METHODS: Advanced melanoma patients with accessible tumours had biopsy performed before the start of treatment with ADI-PEG20 and at the time of progression or relapse when amenable to determine whether argininosuccinate synthetase (ASS) expression in tumour was predictive of response to ADI-PEG20. RESULTS: Twenty-seven of thirty-eight patients treated had melanoma tumours assessable for ASS staining before treatment. Clinical benefit rate (CBR) and longer time to progression were associated with negative expression of tumour ASS. Only 1 of 10 patients with ASS-positive tumours (ASS+) had stable disease, whereas 4 of 17 (24%) had partial response and 5 had stable disease, when ASS expression was negative (ASS-), giving CBR rates of 52.9 vs 10%, P=0.041. Two responding patients with negative ASS expression before therapy had rebiopsy after tumour progression and the ASS expression became positive. The survival of ASS- patients receiving at least four doses at 320 IU m(-2) was significantly better than the ASS+ group at 26.5 vs 8.5 months, P=0.024. CONCLUSION: ADI-PEG20 is safe and the drug is only efficacious in melanoma patients whose tumour has negative ASS expression. Argininosuccinate synthetase tumour positivity is associated with drug resistance and tumour progression.

Arginine deprivation, autophagy, apoptosis (AAA) for the treatment of melanoma.

The majority of melanoma cells do not express argininosuccinate synthetase (ASS), and hence cannot synthesize arginine from citrulline. Their growth and proliferation depend on exogenous supply of arginine. Arginine degradation using arginine deiminase (ADI) leads to growth inhibition and eventually cell death while normal cell which express ASS can survive. This notion has been translated into clinical trial. Pegylated ADI (ADI-PEG20) has shown antitumor activity in melanoma. However, the sensitivity to ADI is different among ASS(-) melanoma cells. We have investigated and reviewed the signaling pathways which are affected by arginine deprivation and their consequences which lead to cell death. We have found that arginine deprivation inhibits mTOR signaling but leads to activation of MEK and ERK with no changes in BRAF. These changes most likely lead to autophagy, a possible mechanism to survive by recycling intracellular arginine. However apoptosis does occur which can be both caspase dependent or independent In order to increase the therapeutic efficacy of this form of treatment, one should consider adding other agent(s) which can drive the cells toward apoptosis or inhibit the autophagic process.

Arginine deprivation as a targeted therapy for cancer.

Certain cancers may be auxotrophic for a particular amino acid, and amino acid deprivation is one method to treat these tumors. Arginine deprivation is a novel approach to target tumors which lack argininosuccinate synthetase (ASS) expression. ASS is a key enzyme which converts citrulline to arginine. Tumors which usually do not express ASS include melanoma, hepatocellular carcinoma, some mesotheliomas and some renal cell cancers. Arginine can be degraded by several enzymes including arginine deiminase (ADI). Although ADI is a microbial enzyme from mycoplasma, it has high affinity to arginine and catalyzes arginine to citrulline and ammonia. Citrulline can be recycled back to arginine in normal cells which express ASS, whereas ASS(-) tumor cells cannot. A pegylated form of ADI (ADI-PEG20) has been formulated and has shown in vitro and in vivo activity against melanoma and hepatocellular carcinoma. ADI-PEG20 induces apoptosis in melanoma cell lines. However, arginine deprivation can also induce ASS expression in certain melanoma cell lines which can lead to in vitro drug resistance. Phase I and II clinical trials with ADI-PEG20 have been conducted in patients with melanoma and hepatocellular carcinoma, and antitumor activity has been demonstrated in both cancers. This article reviews our laboratory and clinical experience as well as that from others with ADI-PEG20 as an antineoplastic agent. Future direction in utilizing this agent is also discussed.

Phase II study of vinorelbine with low dose prednisone in the treatment of hormone-refractory metastatic prostate cancer.

A phase II trial of vinorelbine and low dose prednisone in hormone-refractory metastatic prostate cancer was conducted in order to investigate its safety, efficacy and impact on quality of life. Vinorelbine was administered at the dose of 25 mg/m(2) i.v. weekly for 12 weeks and then biweekly, along with 10 mg of daily oral prednisone until time of progression. Fourteen patients, median age of 74 years, were treated. The treatment was generally well tolerated with leukopenia and anemia as the major side effects. One patient achieved partial remission and eleven remained with stable disease. One of the eleven patients with stable disease had a dramatic PSA response from 1000 to 236 ng/ml; seven of these progressed after week twelve when vinorelbine was given biweekly. PSA response occurred in 5 of 14 patients. The median time to progression was 28 weeks and the median survival was 17 months. Nine out of the 14 accrued patients were evaluable for quality of life assessment. Five of them improved, three remained unchanged and two had a slight worsening. Four patients had improvement in pain control and fatigue. Our preliminary data suggest that the combination of vinorelbine/prednisone has modest activity in metastatic prostate cancer with a very favorable toxicity profile and is very well tolerated in this group of elderly patients.

Correlation of a unique 220-kDa protein with vitamin D sensitivity in glioma cells.

We have investigated the antitumor and apoptotic effects of 1, 25-dihydroxyvitamin D(3) (VD(3)) in glioma cell lines and in primary cultures derived from surgical specimens from patients. Our results showed that certain glioma cells underwent apoptosis, whereas others were resistant. In an attempt to search for parameters that dictate VD(3) sensitivity, we discovered a unique 220-kDa protein in glioma cells that were sensitive to VD(3). This protein was not a classical vitamin D receptor (VDR), but was recognized by two different anti-VDR monoclonal antibodies. Furthermore, the level of the 220-kDa protein was inversely correlated with the IC(50) of VD(3) in these glioma cells. This 220-kDa protein was also present in frozen brain tumor samples, and the level of expression appeared to correlate with their corresponding primary cultures. Thus, our findings suggest that this 220-kDa protein may play an important role in determining VD(3) sensitivity in malignant glioma.

Early MRI findings in high grade glioma.

Magnetic resonance imaging (MRI) is more sensitive than computerized tomography in the detection of many intracerebral lesions; however, the significance of some MRI findings may be unclear. Over four years, nine patients, aged 40-79 years, have been encountered whose initial MRI scans were negative or had minimal abnormalities and soon thereafter had high grade glioma. Initial MRI was performed in eight patients for new-onset seizures and one patient for a focal deficit. MRI was negative in four of the patients and mildly abnormal in five of the patients (small areas of increased T2 and/or minimal enhancement). The initial diagnoses usually included inconclusive differentials of stroke and infection with neoplasm less frequently considered. Radiographic progression leading to the diagnosis of high grade glioma became evident on repeat MRI in 1-8 months with six patients showing progression within three months. All patients underwent surgery and had histologic diagnosis of glioma. Although MRI is quite sensitive, four of the initial scans were negative with reasonable quality studies. Conversely, in five of the initial scans, the tumors were detected when so small that the radiographic findings were not typically diagnostic. Glioma must be considered as a possible cause of initial seizures or new neurologic deficits in adults with normal or minimally abnormal MRI. In this group, seizures were the overwhelming hallmark of presentation. In such a clinical situation, close follow-up with short interval repeat MRI should be performed.

A clinical trial of intravenous vinorelbine tartrate plus tamoxifen in the treatment of patients with advanced malignant melanoma.

BACKGROUND: The aim of the current trial was to assess the efficacy and toxicity of weekly intravenous vinorelbine tartrate with daily oral tamoxifen in the treatment of patients with advanced or metastatic malignant melanoma. METHODS: Thirty-one patients were treated with vinorelbine tartrate, 30 mg/m(2) intravenously, weekly every 13 weeks and then every 2 weeks thereafter until progression of disease or severity of toxicity warranted discontinuation. Tamoxifen, 10 mg orally, twice a day was administered daily starting on Day 1 of chemotherapy with vinorelbine tartrate. Thirty patients had cutaneous melanoma with metastases and 1 patient had ocular melanoma with metastases. Eight patients had received prior chemotherapy. RESULTS: Of the 30 evaluable patients with cutaneous melanoma, 6 achieved a partial response, for an overall response rate of 20% (95% confidence interval, 7-38%). There was no response in the patient with ocular melanoma. Major sites of response include the adrenal gland, lung, tonsil, and cutaneous/subcutaneous tissues. Three patients had a prolonged duration of response lasting > or = 12 months. Side effects generally were mild and tolerable. Grade 3 or 4 hematologic toxicity occurred in 26% and 13% of patients, respectively. Nonhematologic toxicity included mild fatigue, paresthesia, and local arm discomfort from infusion. CONCLUSIONS: Weekly intravenous vinorelbine tartrate plus daily oral tamoxifen appears to be active in the treatment of patients with malignant melanoma. Further clinical trials in malignant melanoma patients treated with vinorelbine tartrate and tamoxifen appear warranted.

A phase I study of chemoembolization with cisplatin, thiotepa, and lipiodol for primary and metastatic liver cancer.

Thirty patients with primary hepatocellular carcinoma or liver metastases were entered into a program of chemoembolization with cisplatin, lipiodol, and escalating doses of thiotepa. Doses of cisplatin were 100/m2, and thiotepa doses ranged from 9 mg/m2 to 24 mg/m2. Two of three patients with ocular melanoma had partial responses in the liver metastases for 3+ and 16 months. In patients with either hepatocellular carcinoma (15 patients) or primary cholangiocarcinoma of the liver (three patients), there were two partial responses, for 22 and 33 months. Five patients had minor responses: four with a 40% reduction in tumor and one with a mixed response. There were four early deaths, which involved sepsis in two patients, respiratory failure in one, and acute myocardial infarction in one. Otherwise, toxicity was tolerable and reversible and included abdominal pain and transient elevation of serum creatinine, bilirubin, and transaminases. Less common toxicities included ototoxicity and peripheral neuropathy. Chemoembolization of the liver with cisplatin, thiotepa, and lipiodol can produce responses, but toxicity can be significant. The recommended starting phase II dose for future studies is thiotepa 24 mg/m2 and cisplatin 100 mg/m2.

A phase II study of intraperitoneal cisplatin and thiotepa in residual ovarian carcinoma: a Gynecologic Oncology Group study.

OBJECTIVE: Patients with advanced epithelial ovarian cancer treated with salvage therapy using new combinations of systemic chemotherapy, radiation therapy, and systemic immunotherapy have had limited success. Since the most common site of relapse or failure to conventional systemic chemotherapy has been the peritoneal cavity, intraperitoneal (IP) chemotherapy was selected to treat small-volume residual disease. METHODS: Sixty-five patients were entered on a protocol using intraperitoneal cisplatin and thiotepa following a response to intravenous cisplatin-based chemotherapy. Patients had surgically documented residual disease (0.5 cm or less maximum tumor diameter) at completion of preprotocol surgery and had no clinical, radiologic, or histologic evidence of extraperitoneal disease. Cisplatin (100 mg/m2) and thiotepa 30 mg/m2 was delivered intraperitoneally every 4 weeks for a maximum of six cycles. The dose of thiotepa was reduced to 12 mg/m2 due to unexpected severe myelosuppression. RESULTS: Of the 52 evaluable patients, grade 4 neutropenia, thrombocytopenia, neurotoxicity, and nephrotoxicity were observed in 31, 19, 13, and 6% of patients, respectively. For all evaluable patients, the complete response rate was 19% and the partial response rate was 2% for a total response rate of 21%. Of 16 patients who had a reassessment laparotomy, 10 patients achieved a surgically documented complete response and 1 patient had a partial response. Four patients are still in response for 67+, 70+, 70+, and 73+ months after third-look surgery. Three patients who did not undergo third-look surgery after chemotherapy are alive and clinically free of disease at 49+, 69+, and 85+ months. CONCLUSION: Thiotepa, when used with cisplatin for IP salvage therapy in patients with advanced or recurrent ovarian cancer, may produce significant myelosuppression and doses must be adjusted accordingly. In cisplatin-sensitive patients with small-volume residual ovarian cancer, IP cisplatin and thiotepa appears to have activity. Determining the utility of this approach will require a randomized trial.

Natural history and prognostic factors for survival in patients with acquired immune deficiency syndrome (AIDS)-related primary central nervous system lymphoma (PCNSL).

The incidence of primary central nervous system lymphoma (PCNSL) is increasing rapidly. It will be the most common primary malignant neoplasm of the brain by the year 2000. PCNSL is an important lethal complication in acquired immunodeficiency syndrome (AIDS) patients. Our objective was to study the natural history and prognostic factors for survival in patients with AIDS-related PCNSL. This is a retrospective cohort study of 75 patients with the diagnosis of AIDS-related PCNSL followed at Jackson Memorial Hospital/University of Miami. Medical records were abstracted for information about age, gender, race, and ethnicity. The method of diagnosis, treatment, and outcome of AIDS and PCNSL in this group were examined. Univariate and multivariate analyses were performed to identify prognostic factors for survival. The median age was 37 years. Males comprised 84% of the patients and 55% of the patients were Hispanic. The most common human immunodeficiency virus (HIV) risk factors were homosexuality and multiple sexual partners. The median cluster designation (CD) 4 count was 15/microl and the median lactic dehydrogensase (LDH) was 1.5x normal. Computed-assisted tomographic (CT) scans of the brain showed multiple lesions in 44% of the patients. Single-photon emission CT scan (SPECT) Thallium-201 of the brain was performed in two-thirds of patients. The most common histologies were immunoblastic and large cell lymphoma. Cranial radiation was given to 72% of the patients, and 55% of them did not complete treatment. The median survival of the group was 1.3 months. Univariate and multivariate analysis showed that longer survival was associated with good performance status (ECOG = 1 to 2 vs. 3 to 4). The presence of prior opportunistic infections, risk factors for AIDS, CD4 counts, level of LDH, ethnicity, gender, duration of symptoms before diagnosis, and race did not influence survival. PCNSL is a neoplasm with a very poor prognosis and short survival even with CNS radiation therapy. Performance status appears to be the main prognostic factor for survival. No significant differences in presentation or outcome were detected between the Hispanic and non-Hispanic patients.

Multidrug-resistant gene expression in small-cell lung cancer.

The development of drug resistance can contribute to treatment failure in small-cell lung cancer (SCLC). In this report, we investigate p-glycoprotein-mediated multidrug resistance (MDR) in these patients. Tumor tissue was obtained prior to treatment and at relapse if possible, short-term culture was carried out, and these tumor cells were analyzed for MDR gene expression by slot blot and reverse transcriptase polymerase chain reaction (RT-PCR) and northern blot analysis. Three cell lines were also established from short-term cultures. Twenty-four patients with MDR(-) and seven with MDR +(++) were available for survival analysis. Median survival for MDR (-) patients was 10 months, whereas for MDR +(++) patients it was 2 months. This was statistically significance (p < 0.0007). The presence of MDR1 gene expression also correlated with the lack of response to chemotherapy (p < 0.001). Increased MDR1 gene expression is usually present in patients with more tumor burden at initial diagnosis. Furthermore, loss of MDR1 gene expression can occur in intrinsically MDR(+) SCLC cells after multiple passages in drug-free media. We concluded that increased MDR1 gene expression is present in a small number of SCLC both before and after chemotherapy and usually signifies poor survival and no response to chemotherapy.

The role of hyperfractionated re-irradiation in metastatic brain disease: a single institutional trial.

Progression of brain metastases after brain irradiation has prompted several studies on retreatment of the brain. Increased durations of survival and improved quality of life have been reported. Fifteen patients with previously treated brain metastases were entered into this pilot study between May 1990 and January 1994. All patients had neurologic and/or radiologic evidence of progression of brain metastases. The lung was the primary site in 60% of cases. The remaining 40% had breast, ovarian, and skin primaries. The median interval between the first treatment and retreatment was 10 months. All patients received whole-brain irradiation with or without a boost for their initial treatment course. Doses ranged from 3,000 to 5,500 cGy for initial treatments (median, 3,000). Retreatment consisted of limited fields with a median side equivalent square of 8.8 cm. Patients were retreated with a median dose of 3,000 cGy (range, 600-3,000 cGy). A median cumulative dose of 6,000 cGy was achieved. Retreatment consisted of twice-daily fractions (150 cGy/fraction). Retreatment was tolerated without serious complications. Of the 15 patients treated, nine (60%) experienced improvement, and five (27%) had stabilization of neurologic function and/or radiographic parameters. Median survival was 3.2 months; two of the reirradiated patients survived > or = 9 months. In conclusion, reirradiation is a viable option in patients with recurrent metastatic lesions of the brain, and the use of a limited retreatment volume makes this a well-tolerated, low-morbidity treatment that leads to clinical benefits and, in some instances, enhanced survival. The influence of hyperfractionation on the outcome needs to be investigated further in large series.

Phase II trial of oral piritrexim in advanced, previously treated transitional cell cancer of bladder.

UNLABELLED: Oral piritrexim (PTX), a second generation antimetabolite, has been shown to be an active agent against methotrexate refractory transitional cell cancer (TCC) of the bladder in phase I trials. We conducted a phase II trial of this drug in patients with TCC of the bladder who failed a first line chemotherapy regimen. METHODS: Oral PTX was started at the dose of 25 mg three times per day for 5 days weekly for 3 weeks followed by one week of rest. If this was tolerated the dose was increased to 50 mg three times a day. Patients were monitored for response rate and toxicity. RESULTS: Seventeen patients were entered into the trial. Two patients did not complete the required 2 courses of treatment to be evaluable. There were 13 evaluable patients. Among the 13 no one achieved a complete response (CR), however, there were 3 partial responses (PRs = RR: 23%) and 5 stable diseases (SDs). The responses lasted 2, 8 and 14 months. The major dose-limiting toxicity was myelosuppression. Two patients died on treatment. One death was due to neutropenic fever and the cause of death in the second patient is thought to be a cerebral vascular accident (CVA). CONCLUSION: PTX is an active drug in the treatment of TCC of the bladder. Bone marrow suppression is the most common dose-limiting toxicity. In view of the observed responses and toxicities in this study and other studies, we suggest that the role of PTX be further investigated in the following clinical settings: 1. Palliative initial treatment in patients with TCC of the bladder who are not candidates for more aggressive chemotherapy. 2. As first line chemotherapy in combination with other active drugs.

Comparison of topoisomerase I and II expression in primary brain tumor and lung cancer.

Topoisomerase I (TOP I) and II (TOP II) activities and their corresponding levels were analyzed in 27 primary brain tumors and 32 lung cancers (28 NSCLC, 4 SCLC). The TOP I and II activities in primary brain tumors varied from 500-2,000 units/mg and 100-3,000 units/mg respectively. Their corresponding levels varied from <0.01-3.30 (TOP I) and 0.24-8.30 (TOP II) arbitrary units. In lung cancer, the TOP I and II activities ranged from 1,000-4,000 and 500-4,000 units/mg respectively with their levels ranging from 0.30-61.60 and 0.2-14.2 arbitrary units respectively. These parameters were compared in both tumors using the Wilcoxon rank sums test, the difference were statically significance for all four parameters with a p<0.0001 for TOP I and II activities and TOP I levels and p<0.09 for TOP II levels. Using linear regression analysis, there was no correlation between TOP I and II activities and their corresponding levels in primary brain tumor. However, in lung cancer, the relationship between TOP I activities and levels were linear with r(2)=0.2 and p<0.0094, but not for TOP II activity and their levels. There was no relationship between TOP I and TOP II levels in the same tumor for both types of cancer. The future clinical implication of these findings are discussed.

Phase II trial of mitoxantrone and cisplatin in advanced non-small-cell lung cancer.

Because in vitro data suggest that mitoxantrone may be synergistic with cisplatin, a Phase II trial of mitoxantrone and cisplatin was conducted in patients with advanced or metastatic non-small-cell lung cancer (NSLC). Twenty-four patients were evaluable for response. Toxicity was tolerable. Partial response occurred in three patients (13%). This response rate is similar to that reported for cisplatin alone in NSLC. Mitoxantrone did not improve the response rate when combined with cisplatin for patients with advanced NSLC.

Retrospective epidemiologic analysis of patients diagnosed with intracranial meningioma from 1977 to 1990 at the Jackson Memorial Hospital, Sylvester Comprehensive Cancer Center: the Jackson Memorial Hospital Tumor Registry experience.

A descriptive analysis was performed of the Tumor Registry data for intracranial meningioma by the Jackson Memorial Hospital, University of Miami School of Medicine Tumor Registry. A total of 108 cases of intracranial meningioma was collected and reviewed. Overall survival for 2, 5, and 10 years was 82, 72, and 60%, respectively. There was no difference in survival for males and females at 5 years, nor any difference in survival for race or ethnicity. There was a trend for improved survival for the young age group (18-55 years).

Phase II trial of piritrexim and DTIC using an alternating dose schedule in metastatic melanoma.

A Phase II trial was conducted in patients with metastatic malignant melanoma with DTIC 250 mg/m2 intravenously for 5 days alternating monthly with Piritrexim (PTX) using an intermittent, low-dose oral administration schedule. PTX was administered at a starting dose of 25 mg orally three times per day for 5 days weekly for 3 weeks followed by 1 week of rest. Twenty-one patients were entered into the study. Among the 17 patients assessable for response, 1 patient had a minor response, and 3 patients had stable disease. No partial or complete response were observed. Toxicity was tolerable and consistent mainly of myelosuppression. Using this alternating dose schedule, PTX and DTIC produced little response in metastatic melanoma.